Imported Upstream version 2.16.0
[platform/upstream/git.git] / dir.c
diff --git a/dir.c b/dir.c
index 7b25634..7c4b45e 100644 (file)
--- a/dir.c
+++ b/dir.c
@@ -7,19 +7,18 @@
  * Copyright (C) Linus Torvalds, 2005-2006
  *              Junio Hamano, 2005-2006
  */
+#define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
+#include "config.h"
 #include "dir.h"
+#include "attr.h"
 #include "refs.h"
 #include "wildmatch.h"
 #include "pathspec.h"
 #include "utf8.h"
 #include "varint.h"
 #include "ewah/ewok.h"
-
-struct path_simplify {
-       int len;
-       const char *path;
-};
+#include "fsmonitor.h"
 
 /*
  * Tells read_directory_recursive how a file or directory should be treated.
@@ -49,26 +48,29 @@ struct cached_dir {
 };
 
 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
-       const char *path, int len, struct untracked_cache_dir *untracked,
-       int check_only, const struct path_simplify *simplify);
-static int get_dtype(struct dirent *de, const char *path, int len);
+       struct index_state *istate, const char *path, int len,
+       struct untracked_cache_dir *untracked,
+       int check_only, int stop_at_first_file, const struct pathspec *pathspec);
+static int get_dtype(struct dirent *de, struct index_state *istate,
+                    const char *path, int len);
 
-/* helper string functions with support for the ignore_case flag */
-int strcmp_icase(const char *a, const char *b)
+int count_slashes(const char *s)
 {
-       return ignore_case ? strcasecmp(a, b) : strcmp(a, b);
+       int cnt = 0;
+       while (*s)
+               if (*s++ == '/')
+                       cnt++;
+       return cnt;
 }
 
-int strncmp_icase(const char *a, const char *b, size_t count)
+int fspathcmp(const char *a, const char *b)
 {
-       return ignore_case ? strncasecmp(a, b, count) : strncmp(a, b, count);
+       return ignore_case ? strcasecmp(a, b) : strcmp(a, b);
 }
 
-int fnmatch_icase(const char *pattern, const char *string, int flags)
+int fspathncmp(const char *a, const char *b, size_t count)
 {
-       return wildmatch(pattern, string,
-                        flags | (ignore_case ? WM_CASEFOLD : 0),
-                        NULL);
+       return ignore_case ? strncasecmp(a, b, count) : strncmp(a, b, count);
 }
 
 int git_fnmatch(const struct pathspec_item *item,
@@ -91,13 +93,11 @@ int git_fnmatch(const struct pathspec_item *item,
        if (item->magic & PATHSPEC_GLOB)
                return wildmatch(pattern, string,
                                 WM_PATHNAME |
-                                (item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0),
-                                NULL);
+                                (item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0));
        else
                /* wildmatch has not learned no FNM_PATHNAME mode yet */
                return wildmatch(pattern, string,
-                                item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0,
-                                NULL);
+                                item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0);
 }
 
 static int fnmatch_icase_mem(const char *pattern, int patternlen,
@@ -121,7 +121,7 @@ static int fnmatch_icase_mem(const char *pattern, int patternlen,
 
        if (ignore_case)
                flags |= WM_CASEFOLD;
-       match_status = wildmatch(use_pat, use_str, flags, NULL);
+       match_status = wildmatch(use_pat, use_str, flags);
 
        strbuf_release(&pat_buf);
        strbuf_release(&str_buf);
@@ -147,7 +147,8 @@ static size_t common_prefix_len(const struct pathspec *pathspec)
                       PATHSPEC_LITERAL |
                       PATHSPEC_GLOB |
                       PATHSPEC_ICASE |
-                      PATHSPEC_EXCLUDE);
+                      PATHSPEC_EXCLUDE |
+                      PATHSPEC_ATTR);
 
        for (n = 0; n < pathspec->nr; n++) {
                size_t i = 0, len = 0, item_len;
@@ -185,19 +186,24 @@ char *common_prefix(const struct pathspec *pathspec)
        return len ? xmemdupz(pathspec->items[0].match, len) : NULL;
 }
 
-int fill_directory(struct dir_struct *dir, const struct pathspec *pathspec)
+int fill_directory(struct dir_struct *dir,
+                  struct index_state *istate,
+                  const struct pathspec *pathspec)
 {
-       size_t len;
+       const char *prefix;
+       size_t prefix_len;
 
        /*
         * Calculate common prefix for the pathspec, and
         * use that to optimize the directory walk
         */
-       len = common_prefix_len(pathspec);
+       prefix_len = common_prefix_len(pathspec);
+       prefix = prefix_len ? pathspec->items[0].match : "";
 
        /* Read the directory and prune it */
-       read_directory(dir, pathspec->nr ? pathspec->_raw[0] : "", len, pathspec);
-       return len;
+       read_directory(dir, istate, prefix, prefix_len, pathspec);
+
+       return prefix_len;
 }
 
 int within_depth(const char *name, int namelen,
@@ -215,8 +221,90 @@ int within_depth(const char *name, int namelen,
        return 1;
 }
 
-#define DO_MATCH_EXCLUDE   1
-#define DO_MATCH_DIRECTORY 2
+/*
+ * Read the contents of the blob with the given OID into a buffer.
+ * Append a trailing LF to the end if the last line doesn't have one.
+ *
+ * Returns:
+ *    -1 when the OID is invalid or unknown or does not refer to a blob.
+ *     0 when the blob is empty.
+ *     1 along with { data, size } of the (possibly augmented) buffer
+ *       when successful.
+ *
+ * Optionally updates the given sha1_stat with the given OID (when valid).
+ */
+static int do_read_blob(const struct object_id *oid,
+                       struct sha1_stat *sha1_stat,
+                       size_t *size_out,
+                       char **data_out)
+{
+       enum object_type type;
+       unsigned long sz;
+       char *data;
+
+       *size_out = 0;
+       *data_out = NULL;
+
+       data = read_sha1_file(oid->hash, &type, &sz);
+       if (!data || type != OBJ_BLOB) {
+               free(data);
+               return -1;
+       }
+
+       if (sha1_stat) {
+               memset(&sha1_stat->stat, 0, sizeof(sha1_stat->stat));
+               hashcpy(sha1_stat->sha1, oid->hash);
+       }
+
+       if (sz == 0) {
+               free(data);
+               return 0;
+       }
+
+       if (data[sz - 1] != '\n') {
+               data = xrealloc(data, st_add(sz, 1));
+               data[sz++] = '\n';
+       }
+
+       *size_out = xsize_t(sz);
+       *data_out = data;
+
+       return 1;
+}
+
+#define DO_MATCH_EXCLUDE   (1<<0)
+#define DO_MATCH_DIRECTORY (1<<1)
+#define DO_MATCH_SUBMODULE (1<<2)
+
+static int match_attrs(const char *name, int namelen,
+                      const struct pathspec_item *item)
+{
+       int i;
+
+       git_check_attr(name, item->attr_check);
+       for (i = 0; i < item->attr_match_nr; i++) {
+               const char *value;
+               int matched;
+               enum attr_match_mode match_mode;
+
+               value = item->attr_check->items[i].value;
+               match_mode = item->attr_match[i].match_mode;
+
+               if (ATTR_TRUE(value))
+                       matched = (match_mode == MATCH_SET);
+               else if (ATTR_FALSE(value))
+                       matched = (match_mode == MATCH_UNSET);
+               else if (ATTR_UNSET(value))
+                       matched = (match_mode == MATCH_UNSPECIFIED);
+               else
+                       matched = (match_mode == MATCH_VALUE &&
+                                  !strcmp(item->attr_match[i].value, value));
+               if (!matched)
+                       return 0;
+       }
+
+       return 1;
+}
 
 /*
  * Does 'match' match the given name?
@@ -270,6 +358,9 @@ static int match_pathspec_item(const struct pathspec_item *item, int prefix,
            strncmp(item->match, name - prefix, item->prefix))
                return 0;
 
+       if (item->attr_match_nr && !match_attrs(name, namelen, item))
+               return 0;
+
        /* If the match was just the prefix, we matched */
        if (!*match)
                return MATCHED_RECURSIVELY;
@@ -291,6 +382,32 @@ static int match_pathspec_item(const struct pathspec_item *item, int prefix,
                         item->nowildcard_len - prefix))
                return MATCHED_FNMATCH;
 
+       /* Perform checks to see if "name" is a super set of the pathspec */
+       if (flags & DO_MATCH_SUBMODULE) {
+               /* name is a literal prefix of the pathspec */
+               if ((namelen < matchlen) &&
+                   (match[namelen] == '/') &&
+                   !ps_strncmp(item, match, name, namelen))
+                       return MATCHED_RECURSIVELY;
+
+               /* name" doesn't match up to the first wild character */
+               if (item->nowildcard_len < item->len &&
+                   ps_strncmp(item, match, name,
+                              item->nowildcard_len - prefix))
+                       return 0;
+
+               /*
+                * Here is where we would perform a wildmatch to check if
+                * "name" can be matched as a directory (or a prefix) against
+                * the pathspec.  Since wildmatch doesn't have this capability
+                * at the present we have to punt and say that it is a match,
+                * potentially returning a false positive
+                * The submodules themselves will be able to perform more
+                * accurate matching to determine if the pathspec matches.
+                */
+               return MATCHED_RECURSIVELY;
+       }
+
        return 0;
 }
 
@@ -322,7 +439,8 @@ static int do_match_pathspec(const struct pathspec *ps,
                       PATHSPEC_LITERAL |
                       PATHSPEC_GLOB |
                       PATHSPEC_ICASE |
-                      PATHSPEC_EXCLUDE);
+                      PATHSPEC_EXCLUDE |
+                      PATHSPEC_ATTR);
 
        if (!ps->nr) {
                if (!ps->recursive ||
@@ -394,6 +512,21 @@ int match_pathspec(const struct pathspec *ps,
        return negative ? 0 : positive;
 }
 
+/**
+ * Check if a submodule is a superset of the pathspec
+ */
+int submodule_path_match(const struct pathspec *ps,
+                        const char *submodule_name,
+                        char *seen)
+{
+       int matched = do_match_pathspec(ps, submodule_name,
+                                       strlen(submodule_name),
+                                       0, seen,
+                                       DO_MATCH_DIRECTORY |
+                                       DO_MATCH_SUBMODULE);
+       return matched;
+}
+
 int report_path_error(const char *ps_matched,
                      const struct pathspec *pathspec,
                      const char *prefix)
@@ -457,7 +590,7 @@ int no_wildcard(const char *string)
 
 void parse_exclude_pattern(const char **pattern,
                           int *patternlen,
-                          int *flags,
+                          unsigned *flags,
                           int *nowildcardlen)
 {
        const char *p = *pattern;
@@ -498,17 +631,12 @@ void add_exclude(const char *string, const char *base,
 {
        struct exclude *x;
        int patternlen;
-       int flags;
+       unsigned flags;
        int nowildcardlen;
 
        parse_exclude_pattern(&string, &patternlen, &flags, &nowildcardlen);
        if (flags & EXC_FLAG_MUSTBEDIR) {
-               char *s;
-               x = xmalloc(sizeof(*x) + patternlen + 1);
-               s = (char *)(x+1);
-               memcpy(s, string, patternlen);
-               s[patternlen] = '\0';
-               x->pattern = s;
+               FLEXPTR_ALLOC_MEM(x, pattern, string, patternlen);
        } else {
                x = xmalloc(sizeof(*x));
                x->pattern = string;
@@ -524,31 +652,22 @@ void add_exclude(const char *string, const char *base,
        x->el = el;
 }
 
-static void *read_skip_worktree_file_from_index(const char *path, size_t *size,
-                                               struct sha1_stat *sha1_stat)
+static int read_skip_worktree_file_from_index(const struct index_state *istate,
+                                             const char *path,
+                                             size_t *size_out,
+                                             char **data_out,
+                                             struct sha1_stat *sha1_stat)
 {
        int pos, len;
-       unsigned long sz;
-       enum object_type type;
-       void *data;
 
        len = strlen(path);
-       pos = cache_name_pos(path, len);
+       pos = index_name_pos(istate, path, len);
        if (pos < 0)
-               return NULL;
-       if (!ce_skip_worktree(active_cache[pos]))
-               return NULL;
-       data = read_sha1_file(active_cache[pos]->sha1, &type, &sz);
-       if (!data || type != OBJ_BLOB) {
-               free(data);
-               return NULL;
-       }
-       *size = xsize_t(sz);
-       if (sha1_stat) {
-               memset(&sha1_stat->stat, 0, sizeof(sha1_stat->stat));
-               hashcpy(sha1_stat->sha1, active_cache[pos]->sha1);
-       }
-       return data;
+               return -1;
+       if (!ce_skip_worktree(istate->cache[pos]))
+               return -1;
+
+       return do_read_blob(&istate->cache[pos]->oid, sha1_stat, size_out, data_out);
 }
 
 /*
@@ -564,9 +683,7 @@ void clear_exclude_list(struct exclude_list *el)
        free(el->excludes);
        free(el->filebuf);
 
-       el->nr = 0;
-       el->excludes = NULL;
-       el->filebuf = NULL;
+       memset(el, 0, sizeof(*el));
 }
 
 static void trim_trailing_spaces(char *buf)
@@ -627,10 +744,7 @@ static struct untracked_cache_dir *lookup_untracked(struct untracked_cache *uc,
        }
 
        uc->dir_created++;
-       d = xmalloc(sizeof(*d) + len + 1);
-       memset(d, 0, sizeof(*d));
-       memcpy(d->name, name, len);
-       d->name[len] = '\0';
+       FLEX_ALLOC_MEM(d, name, name, len);
 
        ALLOC_GROW(dir->dirs, dir->dirs_nr + 1, dir->dirs_alloc);
        memmove(dir->dirs + first + 1, dir->dirs + first,
@@ -667,9 +781,13 @@ static void invalidate_directory(struct untracked_cache *uc,
                dir->dirs[i]->recurse = 0;
 }
 
+static int add_excludes_from_buffer(char *buf, size_t size,
+                                   const char *base, int baselen,
+                                   struct exclude_list *el);
+
 /*
  * Given a file with name "fname", read it (either from disk, or from
- * the index if "check_index" is non-zero), parse it and store the
+ * an index if 'istate' is non-null), parse it and store the
  * exclude rules in "el".
  *
  * If "ss" is not NULL, compute SHA-1 of the exclude file and fill
@@ -677,31 +795,29 @@ static void invalidate_directory(struct untracked_cache *uc,
  * ss_valid is non-zero, "ss" must contain good value as input.
  */
 static int add_excludes(const char *fname, const char *base, int baselen,
-                       struct exclude_list *el, int check_index,
+                       struct exclude_list *el,
+                       struct index_state *istate,
                        struct sha1_stat *sha1_stat)
 {
        struct stat st;
-       int fd, i, lineno = 1;
+       int r;
+       int fd;
        size_t size = 0;
-       char *buf, *entry;
+       char *buf;
 
        fd = open(fname, O_RDONLY);
        if (fd < 0 || fstat(fd, &st) < 0) {
-               if (errno != ENOENT)
-                       warn_on_inaccessible(fname);
-               if (0 <= fd)
+               if (fd < 0)
+                       warn_on_fopen_errors(fname);
+               else
                        close(fd);
-               if (!check_index ||
-                   (buf = read_skip_worktree_file_from_index(fname, &size, sha1_stat)) == NULL)
+               if (!istate)
                        return -1;
-               if (size == 0) {
-                       free(buf);
-                       return 0;
-               }
-               if (buf[size-1] != '\n') {
-                       buf = xrealloc(buf, size+1);
-                       buf[size++] = '\n';
-               }
+               r = read_skip_worktree_file_from_index(istate, fname,
+                                                      &size, &buf,
+                                                      sha1_stat);
+               if (r != 1)
+                       return r;
        } else {
                size = xsize_t(st.st_size);
                if (size == 0) {
@@ -713,7 +829,7 @@ static int add_excludes(const char *fname, const char *base, int baselen,
                        close(fd);
                        return 0;
                }
-               buf = xmalloc(size+1);
+               buf = xmallocz(size);
                if (read_in_full(fd, buf, size) != size) {
                        free(buf);
                        close(fd);
@@ -724,14 +840,15 @@ static int add_excludes(const char *fname, const char *base, int baselen,
                if (sha1_stat) {
                        int pos;
                        if (sha1_stat->valid &&
-                           !match_stat_data_racy(&the_index, &sha1_stat->stat, &st))
+                           !match_stat_data_racy(istate, &sha1_stat->stat, &st))
                                ; /* no content change, ss->sha1 still good */
-                       else if (check_index &&
-                                (pos = cache_name_pos(fname, strlen(fname))) >= 0 &&
-                                !ce_stage(active_cache[pos]) &&
-                                ce_uptodate(active_cache[pos]) &&
-                                !would_convert_to_git(fname))
-                               hashcpy(sha1_stat->sha1, active_cache[pos]->sha1);
+                       else if (istate &&
+                                (pos = index_name_pos(istate, fname, strlen(fname))) >= 0 &&
+                                !ce_stage(istate->cache[pos]) &&
+                                ce_uptodate(istate->cache[pos]) &&
+                                !would_convert_to_git(istate, fname))
+                               hashcpy(sha1_stat->sha1,
+                                       istate->cache[pos]->oid.hash);
                        else
                                hash_sha1_file(buf, size, "blob", sha1_stat->sha1);
                        fill_stat_data(&sha1_stat->stat, &st);
@@ -739,6 +856,17 @@ static int add_excludes(const char *fname, const char *base, int baselen,
                }
        }
 
+       add_excludes_from_buffer(buf, size, base, baselen, el);
+       return 0;
+}
+
+static int add_excludes_from_buffer(char *buf, size_t size,
+                                   const char *base, int baselen,
+                                   struct exclude_list *el)
+{
+       int i, lineno = 1;
+       char *entry;
+
        el->filebuf = buf;
 
        if (skip_utf8_bom(&buf, size))
@@ -762,9 +890,26 @@ static int add_excludes(const char *fname, const char *base, int baselen,
 
 int add_excludes_from_file_to_list(const char *fname, const char *base,
                                   int baselen, struct exclude_list *el,
-                                  int check_index)
+                                  struct index_state *istate)
 {
-       return add_excludes(fname, base, baselen, el, check_index, NULL);
+       return add_excludes(fname, base, baselen, el, istate, NULL);
+}
+
+int add_excludes_from_blob_to_list(
+       struct object_id *oid,
+       const char *base, int baselen,
+       struct exclude_list *el)
+{
+       char *buf;
+       size_t size;
+       int r;
+
+       r = do_read_blob(oid, NULL, &size, &buf);
+       if (r != 1)
+               return r;
+
+       add_excludes_from_buffer(buf, size, base, baselen, el);
+       return 0;
 }
 
 struct exclude_list *add_exclude_list(struct dir_struct *dir,
@@ -796,7 +941,7 @@ static void add_excludes_from_file_1(struct dir_struct *dir, const char *fname,
        if (!dir->untracked)
                dir->unmanaged_exclude_files++;
        el = add_exclude_list(dir, EXC_FILE, fname);
-       if (add_excludes(fname, "", 0, el, 0, sha1_stat) < 0)
+       if (add_excludes(fname, "", 0, el, NULL, sha1_stat) < 0)
                die("cannot use %s as an exclude file", fname);
 }
 
@@ -808,16 +953,16 @@ void add_excludes_from_file(struct dir_struct *dir, const char *fname)
 
 int match_basename(const char *basename, int basenamelen,
                   const char *pattern, int prefix, int patternlen,
-                  int flags)
+                  unsigned flags)
 {
        if (prefix == patternlen) {
                if (patternlen == basenamelen &&
-                   !strncmp_icase(pattern, basename, basenamelen))
+                   !fspathncmp(pattern, basename, basenamelen))
                        return 1;
        } else if (flags & EXC_FLAG_ENDSWITH) {
                /* "*literal" matching against "fooliteral" */
                if (patternlen - 1 <= basenamelen &&
-                   !strncmp_icase(pattern + 1,
+                   !fspathncmp(pattern + 1,
                                   basename + basenamelen - (patternlen - 1),
                                   patternlen - 1))
                        return 1;
@@ -833,7 +978,7 @@ int match_basename(const char *basename, int basenamelen,
 int match_pathname(const char *pathname, int pathlen,
                   const char *base, int baselen,
                   const char *pattern, int prefix, int patternlen,
-                  int flags)
+                  unsigned flags)
 {
        const char *name;
        int namelen;
@@ -854,7 +999,7 @@ int match_pathname(const char *pathname, int pathlen,
         */
        if (pathlen < baselen + 1 ||
            (baselen && pathname[baselen] != '/') ||
-           strncmp_icase(pathname, base, baselen))
+           fspathncmp(pathname, base, baselen))
                return 0;
 
        namelen = baselen ? pathlen - baselen - 1 : pathlen;
@@ -868,7 +1013,7 @@ int match_pathname(const char *pathname, int pathlen,
                if (prefix > namelen)
                        return 0;
 
-               if (strncmp_icase(pattern, name, prefix))
+               if (fspathncmp(pattern, name, prefix))
                        return 0;
                pattern += prefix;
                patternlen -= prefix;
@@ -899,8 +1044,10 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
                                                       int pathlen,
                                                       const char *basename,
                                                       int *dtype,
-                                                      struct exclude_list *el)
+                                                      struct exclude_list *el,
+                                                      struct index_state *istate)
 {
+       struct exclude *exc = NULL; /* undecided */
        int i;
 
        if (!el->nr)
@@ -913,7 +1060,7 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
 
                if (x->flags & EXC_FLAG_MUSTBEDIR) {
                        if (*dtype == DT_UNKNOWN)
-                               *dtype = get_dtype(NULL, pathname, pathlen);
+                               *dtype = get_dtype(NULL, istate, pathname, pathlen);
                        if (*dtype != DT_DIR)
                                continue;
                }
@@ -922,18 +1069,22 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
                        if (match_basename(basename,
                                           pathlen - (basename - pathname),
                                           exclude, prefix, x->patternlen,
-                                          x->flags))
-                               return x;
+                                          x->flags)) {
+                               exc = x;
+                               break;
+                       }
                        continue;
                }
 
                assert(x->baselen == 0 || x->base[x->baselen - 1] == '/');
                if (match_pathname(pathname, pathlen,
                                   x->base, x->baselen ? x->baselen - 1 : 0,
-                                  exclude, prefix, x->patternlen, x->flags))
-                       return x;
+                                  exclude, prefix, x->patternlen, x->flags)) {
+                       exc = x;
+                       break;
+               }
        }
-       return NULL; /* undecided */
+       return exc;
 }
 
 /*
@@ -942,16 +1093,18 @@ static struct exclude *last_exclude_matching_from_list(const char *pathname,
  */
 int is_excluded_from_list(const char *pathname,
                          int pathlen, const char *basename, int *dtype,
-                         struct exclude_list *el)
+                         struct exclude_list *el, struct index_state *istate)
 {
        struct exclude *exclude;
-       exclude = last_exclude_matching_from_list(pathname, pathlen, basename, dtype, el);
+       exclude = last_exclude_matching_from_list(pathname, pathlen, basename,
+                                                 dtype, el, istate);
        if (exclude)
                return exclude->flags & EXC_FLAG_NEGATIVE ? 0 : 1;
        return -1; /* undecided */
 }
 
 static struct exclude *last_exclude_matching_from_lists(struct dir_struct *dir,
+                                                       struct index_state *istate,
                const char *pathname, int pathlen, const char *basename,
                int *dtype_p)
 {
@@ -963,7 +1116,7 @@ static struct exclude *last_exclude_matching_from_lists(struct dir_struct *dir,
                for (j = group->nr - 1; j >= 0; j--) {
                        exclude = last_exclude_matching_from_list(
                                pathname, pathlen, basename, dtype_p,
-                               &group->el[j]);
+                               &group->el[j], istate);
                        if (exclude)
                                return exclude;
                }
@@ -975,7 +1128,9 @@ static struct exclude *last_exclude_matching_from_lists(struct dir_struct *dir,
  * Loads the per-directory exclude list for the substring of base
  * which has a char length of baselen.
  */
-static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
+static void prep_exclude(struct dir_struct *dir,
+                        struct index_state *istate,
+                        const char *base, int baselen)
 {
        struct exclude_list_group *group;
        struct exclude_list *el;
@@ -1054,6 +1209,7 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
                        int dt = DT_DIR;
                        dir->basebuf.buf[stk->baselen - 1] = 0;
                        dir->exclude = last_exclude_matching_from_lists(dir,
+                                                                       istate,
                                dir->basebuf.buf, stk->baselen - 1,
                                dir->basebuf.buf + current, &dt);
                        dir->basebuf.buf[stk->baselen - 1] = '/';
@@ -1095,7 +1251,7 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
                        strbuf_addbuf(&sb, &dir->basebuf);
                        strbuf_addstr(&sb, dir->exclude_per_dir);
                        el->src = strbuf_detach(&sb, NULL);
-                       add_excludes(el->src, el->src, stk->baselen, el, 1,
+                       add_excludes(el->src, el->src, stk->baselen, el, istate,
                                     untracked ? &sha1_stat : NULL);
                }
                /*
@@ -1130,19 +1286,20 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
  * undecided.
  */
 struct exclude *last_exclude_matching(struct dir_struct *dir,
-                                            const char *pathname,
-                                            int *dtype_p)
+                                     struct index_state *istate,
+                                     const char *pathname,
+                                     int *dtype_p)
 {
        int pathlen = strlen(pathname);
        const char *basename = strrchr(pathname, '/');
        basename = (basename) ? basename+1 : pathname;
 
-       prep_exclude(dir, pathname, basename-pathname);
+       prep_exclude(dir, istate, pathname, basename-pathname);
 
        if (dir->exclude)
                return dir->exclude;
 
-       return last_exclude_matching_from_lists(dir, pathname, pathlen,
+       return last_exclude_matching_from_lists(dir, istate, pathname, pathlen,
                        basename, dtype_p);
 }
 
@@ -1151,10 +1308,11 @@ struct exclude *last_exclude_matching(struct dir_struct *dir,
  * scans all exclude lists to determine whether pathname is excluded.
  * Returns 1 if true, otherwise 0.
  */
-int is_excluded(struct dir_struct *dir, const char *pathname, int *dtype_p)
+int is_excluded(struct dir_struct *dir, struct index_state *istate,
+               const char *pathname, int *dtype_p)
 {
        struct exclude *exclude =
-               last_exclude_matching(dir, pathname, dtype_p);
+               last_exclude_matching(dir, istate, pathname, dtype_p);
        if (exclude)
                return exclude->flags & EXC_FLAG_NEGATIVE ? 0 : 1;
        return 0;
@@ -1164,25 +1322,27 @@ static struct dir_entry *dir_entry_new(const char *pathname, int len)
 {
        struct dir_entry *ent;
 
-       ent = xmalloc(sizeof(*ent) + len + 1);
+       FLEX_ALLOC_MEM(ent, name, pathname, len);
        ent->len = len;
-       memcpy(ent->name, pathname, len);
-       ent->name[len] = 0;
        return ent;
 }
 
-static struct dir_entry *dir_add_name(struct dir_struct *dir, const char *pathname, int len)
+static struct dir_entry *dir_add_name(struct dir_struct *dir,
+                                     struct index_state *istate,
+                                     const char *pathname, int len)
 {
-       if (cache_file_exists(pathname, len, ignore_case))
+       if (index_file_exists(istate, pathname, len, ignore_case))
                return NULL;
 
        ALLOC_GROW(dir->entries, dir->nr+1, dir->alloc);
        return dir->entries[dir->nr++] = dir_entry_new(pathname, len);
 }
 
-struct dir_entry *dir_add_ignored(struct dir_struct *dir, const char *pathname, int len)
+struct dir_entry *dir_add_ignored(struct dir_struct *dir,
+                                 struct index_state *istate,
+                                 const char *pathname, int len)
 {
-       if (!cache_name_is_other(pathname, len))
+       if (!index_name_is_other(istate, pathname, len))
                return NULL;
 
        ALLOC_GROW(dir->ignored, dir->ignored_nr+1, dir->ignored_alloc);
@@ -1200,31 +1360,18 @@ enum exist_status {
  * the directory name; instead, use the case insensitive
  * directory hash.
  */
-static enum exist_status directory_exists_in_index_icase(const char *dirname, int len)
+static enum exist_status directory_exists_in_index_icase(struct index_state *istate,
+                                                        const char *dirname, int len)
 {
-       const struct cache_entry *ce = cache_dir_exists(dirname, len);
-       unsigned char endchar;
-
-       if (!ce)
-               return index_nonexistent;
-       endchar = ce->name[len];
+       struct cache_entry *ce;
 
-       /*
-        * The cache_entry structure returned will contain this dirname
-        * and possibly additional path components.
-        */
-       if (endchar == '/')
+       if (index_dir_exists(istate, dirname, len))
                return index_directory;
 
-       /*
-        * If there are no additional path components, then this cache_entry
-        * represents a submodule.  Submodules, despite being directories,
-        * are stored in the cache without a closing slash.
-        */
-       if (!endchar && S_ISGITLINK(ce->ce_mode))
+       ce = index_file_exists(istate, dirname, len, ignore_case);
+       if (ce && S_ISGITLINK(ce->ce_mode))
                return index_gitdir;
 
-       /* This should never be hit, but it exists just in case. */
        return index_nonexistent;
 }
 
@@ -1235,18 +1382,19 @@ static enum exist_status directory_exists_in_index_icase(const char *dirname, in
  * the files it contains) will sort with the '/' at the
  * end.
  */
-static enum exist_status directory_exists_in_index(const char *dirname, int len)
+static enum exist_status directory_exists_in_index(struct index_state *istate,
+                                                  const char *dirname, int len)
 {
        int pos;
 
        if (ignore_case)
-               return directory_exists_in_index_icase(dirname, len);
+               return directory_exists_in_index_icase(istate, dirname, len);
 
-       pos = cache_name_pos(dirname, len);
+       pos = index_name_pos(istate, dirname, len);
        if (pos < 0)
                pos = -pos-1;
-       while (pos < active_nr) {
-               const struct cache_entry *ce = active_cache[pos++];
+       while (pos < istate->cache_nr) {
+               const struct cache_entry *ce = istate->cache[pos++];
                unsigned char endchar;
 
                if (strncmp(ce->name, dirname, len))
@@ -1296,12 +1444,13 @@ static enum exist_status directory_exists_in_index(const char *dirname, int len)
  *  (c) otherwise, we recurse into it.
  */
 static enum path_treatment treat_directory(struct dir_struct *dir,
+       struct index_state *istate,
        struct untracked_cache_dir *untracked,
        const char *dirname, int len, int baselen, int exclude,
-       const struct path_simplify *simplify)
+       const struct pathspec *pathspec)
 {
        /* The "len-1" is to strip the final '/' */
-       switch (directory_exists_in_index(dirname, len-1)) {
+       switch (directory_exists_in_index(istate, dirname, len-1)) {
        case index_directory:
                return path_recurse;
 
@@ -1311,10 +1460,34 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
        case index_nonexistent:
                if (dir->flags & DIR_SHOW_OTHER_DIRECTORIES)
                        break;
+               if (exclude &&
+                       (dir->flags & DIR_SHOW_IGNORED_TOO) &&
+                       (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING)) {
+
+                       /*
+                        * This is an excluded directory and we are
+                        * showing ignored paths that match an exclude
+                        * pattern.  (e.g. show directory as ignored
+                        * only if it matches an exclude pattern).
+                        * This path will either be 'path_excluded`
+                        * (if we are showing empty directories or if
+                        * the directory is not empty), or will be
+                        * 'path_none' (empty directory, and we are
+                        * not showing empty directories).
+                        */
+                       if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
+                               return path_excluded;
+
+                       if (read_directory_recursive(dir, istate, dirname, len,
+                                                    untracked, 1, 1, pathspec) == path_excluded)
+                               return path_excluded;
+
+                       return path_none;
+               }
                if (!(dir->flags & DIR_NO_GITLINKS)) {
-                       unsigned char sha1[20];
-                       if (resolve_gitlink_ref(dirname, "HEAD", sha1) == 0)
-                               return path_untracked;
+                       struct object_id oid;
+                       if (resolve_gitlink_ref(dirname, "HEAD", &oid) == 0)
+                               return exclude ? path_excluded : path_untracked;
                }
                return path_recurse;
        }
@@ -1326,8 +1499,13 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 
        untracked = lookup_untracked(dir->untracked, untracked,
                                     dirname + baselen, len - baselen);
-       return read_directory_recursive(dir, dirname, len,
-                                       untracked, 1, simplify);
+
+       /*
+        * If this is an excluded directory, then we only need to check if
+        * the directory contains any files.
+        */
+       return read_directory_recursive(dir, istate, dirname, len,
+                                       untracked, 1, exclude, pathspec);
 }
 
 /*
@@ -1335,24 +1513,34 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
  * reading - if the path cannot possibly be in the pathspec,
  * return true, and we'll skip it early.
  */
-static int simplify_away(const char *path, int pathlen, const struct path_simplify *simplify)
+static int simplify_away(const char *path, int pathlen,
+                        const struct pathspec *pathspec)
 {
-       if (simplify) {
-               for (;;) {
-                       const char *match = simplify->path;
-                       int len = simplify->len;
+       int i;
 
-                       if (!match)
-                               break;
-                       if (len > pathlen)
-                               len = pathlen;
-                       if (!memcmp(path, match, len))
-                               return 0;
-                       simplify++;
-               }
-               return 1;
+       if (!pathspec || !pathspec->nr)
+               return 0;
+
+       GUARD_PATHSPEC(pathspec,
+                      PATHSPEC_FROMTOP |
+                      PATHSPEC_MAXDEPTH |
+                      PATHSPEC_LITERAL |
+                      PATHSPEC_GLOB |
+                      PATHSPEC_ICASE |
+                      PATHSPEC_EXCLUDE |
+                      PATHSPEC_ATTR);
+
+       for (i = 0; i < pathspec->nr; i++) {
+               const struct pathspec_item *item = &pathspec->items[i];
+               int len = item->nowildcard_len;
+
+               if (len > pathlen)
+                       len = pathlen;
+               if (!ps_strncmp(item, item->match, path, len))
+                       return 0;
        }
-       return 0;
+
+       return 1;
 }
 
 /*
@@ -1366,29 +1554,44 @@ static int simplify_away(const char *path, int pathlen, const struct path_simpli
  *   2. the path is a directory prefix of some element in the
  *      pathspec
  */
-static int exclude_matches_pathspec(const char *path, int len,
-               const struct path_simplify *simplify)
-{
-       if (simplify) {
-               for (; simplify->path; simplify++) {
-                       if (len == simplify->len
-                           && !memcmp(path, simplify->path, len))
-                               return 1;
-                       if (len < simplify->len
-                           && simplify->path[len] == '/'
-                           && !memcmp(path, simplify->path, len))
-                               return 1;
-               }
+static int exclude_matches_pathspec(const char *path, int pathlen,
+                                   const struct pathspec *pathspec)
+{
+       int i;
+
+       if (!pathspec || !pathspec->nr)
+               return 0;
+
+       GUARD_PATHSPEC(pathspec,
+                      PATHSPEC_FROMTOP |
+                      PATHSPEC_MAXDEPTH |
+                      PATHSPEC_LITERAL |
+                      PATHSPEC_GLOB |
+                      PATHSPEC_ICASE |
+                      PATHSPEC_EXCLUDE);
+
+       for (i = 0; i < pathspec->nr; i++) {
+               const struct pathspec_item *item = &pathspec->items[i];
+               int len = item->nowildcard_len;
+
+               if (len == pathlen &&
+                   !ps_strncmp(item, item->match, path, pathlen))
+                       return 1;
+               if (len > pathlen &&
+                   item->match[pathlen] == '/' &&
+                   !ps_strncmp(item, item->match, path, pathlen))
+                       return 1;
        }
        return 0;
 }
 
-static int get_index_dtype(const char *path, int len)
+static int get_index_dtype(struct index_state *istate,
+                          const char *path, int len)
 {
        int pos;
        const struct cache_entry *ce;
 
-       ce = cache_file_exists(path, len, 0);
+       ce = index_file_exists(istate, path, len, 0);
        if (ce) {
                if (!ce_uptodate(ce))
                        return DT_UNKNOWN;
@@ -1402,12 +1605,12 @@ static int get_index_dtype(const char *path, int len)
        }
 
        /* Try to look it up as a directory */
-       pos = cache_name_pos(path, len);
+       pos = index_name_pos(istate, path, len);
        if (pos >= 0)
                return DT_UNKNOWN;
        pos = -pos-1;
-       while (pos < active_nr) {
-               ce = active_cache[pos++];
+       while (pos < istate->cache_nr) {
+               ce = istate->cache[pos++];
                if (strncmp(ce->name, path, len))
                        break;
                if (ce->name[len] > '/')
@@ -1421,14 +1624,15 @@ static int get_index_dtype(const char *path, int len)
        return DT_UNKNOWN;
 }
 
-static int get_dtype(struct dirent *de, const char *path, int len)
+static int get_dtype(struct dirent *de, struct index_state *istate,
+                    const char *path, int len)
 {
        int dtype = de ? DTYPE(de) : DT_UNKNOWN;
        struct stat st;
 
        if (dtype != DT_UNKNOWN)
                return dtype;
-       dtype = get_index_dtype(path, len);
+       dtype = get_index_dtype(istate, path, len);
        if (dtype != DT_UNKNOWN)
                return dtype;
        if (lstat(path, &st))
@@ -1444,16 +1648,18 @@ static int get_dtype(struct dirent *de, const char *path, int len)
 
 static enum path_treatment treat_one_path(struct dir_struct *dir,
                                          struct untracked_cache_dir *untracked,
+                                         struct index_state *istate,
                                          struct strbuf *path,
                                          int baselen,
-                                         const struct path_simplify *simplify,
+                                         const struct pathspec *pathspec,
                                          int dtype, struct dirent *de)
 {
        int exclude;
-       int has_path_in_index = !!cache_file_exists(path->buf, path->len, ignore_case);
+       int has_path_in_index = !!index_file_exists(istate, path->buf, path->len, ignore_case);
+       enum path_treatment path_treatment;
 
        if (dtype == DT_UNKNOWN)
-               dtype = get_dtype(de, path->buf, path->len);
+               dtype = get_dtype(de, istate, path->buf, path->len);
 
        /* Always exclude indexed files */
        if (dtype != DT_DIR && has_path_in_index)
@@ -1480,10 +1686,10 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
        if ((dir->flags & DIR_COLLECT_KILLED_ONLY) &&
            (dtype == DT_DIR) &&
            !has_path_in_index &&
-           (directory_exists_in_index(path->buf, path->len) == index_nonexistent))
+           (directory_exists_in_index(istate, path->buf, path->len) == index_nonexistent))
                return path_none;
 
-       exclude = is_excluded(dir, path->buf, &dtype);
+       exclude = is_excluded(dir, istate, path->buf, &dtype);
 
        /*
         * Excluded? If we don't explicitly want to show
@@ -1497,8 +1703,23 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
                return path_none;
        case DT_DIR:
                strbuf_addch(path, '/');
-               return treat_directory(dir, untracked, path->buf, path->len,
-                                      baselen, exclude, simplify);
+               path_treatment = treat_directory(dir, istate, untracked,
+                                                path->buf, path->len,
+                                                baselen, exclude, pathspec);
+               /*
+                * If 1) we only want to return directories that
+                * match an exclude pattern and 2) this directory does
+                * not match an exclude pattern but all of its
+                * contents are excluded, then indicate that we should
+                * recurse into this directory (instead of marking the
+                * directory itself as an ignored path).
+                */
+               if (!exclude &&
+                   path_treatment == path_excluded &&
+                   (dir->flags & DIR_SHOW_IGNORED_TOO) &&
+                   (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING))
+                       return path_recurse;
+               return path_treatment;
        case DT_REG:
        case DT_LNK:
                return exclude ? path_excluded : path_untracked;
@@ -1508,9 +1729,10 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
 static enum path_treatment treat_path_fast(struct dir_struct *dir,
                                           struct untracked_cache_dir *untracked,
                                           struct cached_dir *cdir,
+                                          struct index_state *istate,
                                           struct strbuf *path,
                                           int baselen,
-                                          const struct path_simplify *simplify)
+                                          const struct pathspec *pathspec)
 {
        strbuf_setlen(path, baselen);
        if (!cdir->ucd) {
@@ -1519,16 +1741,15 @@ static enum path_treatment treat_path_fast(struct dir_struct *dir,
        }
        strbuf_addstr(path, cdir->ucd->name);
        /* treat_one_path() does this before it calls treat_directory() */
-       if (path->buf[path->len - 1] != '/')
-               strbuf_addch(path, '/');
+       strbuf_complete(path, '/');
        if (cdir->ucd->check_only)
                /*
                 * check_only is set as a result of treat_directory() getting
                 * to its bottom. Verify again the same set of directories
                 * with check_only set.
                 */
-               return read_directory_recursive(dir, path->buf, path->len,
-                                               cdir->ucd, 1, simplify);
+               return read_directory_recursive(dir, istate, path->buf, path->len,
+                                               cdir->ucd, 1, 0, pathspec);
        /*
         * We get path_recurse in the first run when
         * directory_exists_in_index() returns index_nonexistent. We
@@ -1541,25 +1762,26 @@ static enum path_treatment treat_path_fast(struct dir_struct *dir,
 static enum path_treatment treat_path(struct dir_struct *dir,
                                      struct untracked_cache_dir *untracked,
                                      struct cached_dir *cdir,
+                                     struct index_state *istate,
                                      struct strbuf *path,
                                      int baselen,
-                                     const struct path_simplify *simplify)
+                                     const struct pathspec *pathspec)
 {
        int dtype;
        struct dirent *de = cdir->de;
 
        if (!de)
-               return treat_path_fast(dir, untracked, cdir, path,
-                                      baselen, simplify);
+               return treat_path_fast(dir, untracked, cdir, istate, path,
+                                      baselen, pathspec);
        if (is_dot_or_dotdot(de->d_name) || !strcmp(de->d_name, ".git"))
                return path_none;
        strbuf_setlen(path, baselen);
        strbuf_addstr(path, de->d_name);
-       if (simplify_away(path->buf, path->len, simplify))
+       if (simplify_away(path->buf, path->len, pathspec))
                return path_none;
 
        dtype = DTYPE(de);
-       return treat_one_path(dir, untracked, path, baselen, simplify, dtype, de);
+       return treat_one_path(dir, untracked, istate, path, baselen, pathspec, dtype, de);
 }
 
 static void add_untracked(struct untracked_cache_dir *dir, const char *name)
@@ -1573,6 +1795,7 @@ static void add_untracked(struct untracked_cache_dir *dir, const char *name)
 
 static int valid_cached_dir(struct dir_struct *dir,
                            struct untracked_cache_dir *untracked,
+                           struct index_state *istate,
                            struct strbuf *path,
                            int check_only)
 {
@@ -1581,17 +1804,23 @@ static int valid_cached_dir(struct dir_struct *dir,
        if (!untracked)
                return 0;
 
-       if (stat(path->len ? path->buf : ".", &st)) {
-               invalidate_directory(dir->untracked, untracked);
-               memset(&untracked->stat_data, 0, sizeof(untracked->stat_data));
-               return 0;
-       }
-       if (!untracked->valid ||
-           match_stat_data_racy(&the_index, &untracked->stat_data, &st)) {
-               if (untracked->valid)
+       /*
+        * With fsmonitor, we can trust the untracked cache's valid field.
+        */
+       refresh_fsmonitor(istate);
+       if (!(dir->untracked->use_fsmonitor && untracked->valid)) {
+               if (stat(path->len ? path->buf : ".", &st)) {
                        invalidate_directory(dir->untracked, untracked);
-               fill_stat_data(&untracked->stat_data, &st);
-               return 0;
+                       memset(&untracked->stat_data, 0, sizeof(untracked->stat_data));
+                       return 0;
+               }
+               if (!untracked->valid ||
+                       match_stat_data_racy(istate, &untracked->stat_data, &st)) {
+                       if (untracked->valid)
+                               invalidate_directory(dir->untracked, untracked);
+                       fill_stat_data(&untracked->stat_data, &st);
+                       return 0;
+               }
        }
 
        if (untracked->check_only != !!check_only) {
@@ -1608,10 +1837,10 @@ static int valid_cached_dir(struct dir_struct *dir,
         */
        if (path->len && path->buf[path->len - 1] != '/') {
                strbuf_addch(path, '/');
-               prep_exclude(dir, path->buf, path->len);
+               prep_exclude(dir, istate, path->buf, path->len);
                strbuf_setlen(path, path->len - 1);
        } else
-               prep_exclude(dir, path->buf, path->len);
+               prep_exclude(dir, istate, path->buf, path->len);
 
        /* hopefully prep_exclude() haven't invalidated this entry... */
        return untracked->valid;
@@ -1620,12 +1849,13 @@ static int valid_cached_dir(struct dir_struct *dir,
 static int open_cached_dir(struct cached_dir *cdir,
                           struct dir_struct *dir,
                           struct untracked_cache_dir *untracked,
+                          struct index_state *istate,
                           struct strbuf *path,
                           int check_only)
 {
        memset(cdir, 0, sizeof(*cdir));
        cdir->untracked = untracked;
-       if (valid_cached_dir(dir, untracked, path, check_only))
+       if (valid_cached_dir(dir, untracked, istate, path, check_only))
                return 0;
        cdir->fdir = opendir(path->len ? path->buf : ".");
        if (dir->untracked)
@@ -1685,12 +1915,20 @@ static void close_cached_dir(struct cached_dir *cdir)
  * Also, we ignore the name ".git" (even if it is not a directory).
  * That likely will not change.
  *
+ * If 'stop_at_first_file' is specified, 'path_excluded' is returned
+ * to signal that a file was found. This is the least significant value that
+ * indicates that a file was encountered that does not depend on the order of
+ * whether an untracked or exluded path was encountered first.
+ *
  * Returns the most significant path_treatment value encountered in the scan.
+ * If 'stop_at_first_file' is specified, `path_excluded` is the most
+ * significant path_treatment value that will be returned.
  */
+
 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
-                                   const char *base, int baselen,
-                                   struct untracked_cache_dir *untracked, int check_only,
-                                   const struct path_simplify *simplify)
+       struct index_state *istate, const char *base, int baselen,
+       struct untracked_cache_dir *untracked, int check_only,
+       int stop_at_first_file, const struct pathspec *pathspec)
 {
        struct cached_dir cdir;
        enum path_treatment state, subdir_state, dir_state = path_none;
@@ -1698,7 +1936,7 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 
        strbuf_add(&path, base, baselen);
 
-       if (open_cached_dir(&cdir, dir, untracked, &path, check_only))
+       if (open_cached_dir(&cdir, dir, untracked, istate, &path, check_only))
                goto out;
 
        if (untracked)
@@ -1706,25 +1944,52 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 
        while (!read_cached_dir(&cdir)) {
                /* check how the file or directory should be treated */
-               state = treat_path(dir, untracked, &cdir, &path, baselen, simplify);
+               state = treat_path(dir, untracked, &cdir, istate, &path,
+                                  baselen, pathspec);
 
                if (state > dir_state)
                        dir_state = state;
 
                /* recurse into subdir if instructed by treat_path */
-               if (state == path_recurse) {
+               if ((state == path_recurse) ||
+                       ((state == path_untracked) &&
+                        (dir->flags & DIR_SHOW_IGNORED_TOO) &&
+                        (get_dtype(cdir.de, istate, path.buf, path.len) == DT_DIR))) {
                        struct untracked_cache_dir *ud;
                        ud = lookup_untracked(dir->untracked, untracked,
                                              path.buf + baselen,
                                              path.len - baselen);
                        subdir_state =
-                               read_directory_recursive(dir, path.buf, path.len,
-                                                        ud, check_only, simplify);
+                               read_directory_recursive(dir, istate, path.buf,
+                                                        path.len, ud,
+                                                        check_only, stop_at_first_file, pathspec);
                        if (subdir_state > dir_state)
                                dir_state = subdir_state;
                }
 
                if (check_only) {
+                       if (stop_at_first_file) {
+                               /*
+                                * If stopping at first file, then
+                                * signal that a file was found by
+                                * returning `path_excluded`. This is
+                                * to return a consistent value
+                                * regardless of whether an ignored or
+                                * excluded file happened to be
+                                * encountered 1st.
+                                *
+                                * In current usage, the
+                                * `stop_at_first_file` is passed when
+                                * an ancestor directory has matched
+                                * an exclude pattern, so any found
+                                * files will be excluded.
+                                */
+                               if (dir_state >= path_excluded) {
+                                       dir_state = path_excluded;
+                                       break;
+                               }
+                       }
+
                        /* abort early if maximum state has been reached */
                        if (dir_state == path_untracked) {
                                if (cdir.fdir)
@@ -1739,18 +2004,18 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
                switch (state) {
                case path_excluded:
                        if (dir->flags & DIR_SHOW_IGNORED)
-                               dir_add_name(dir, path.buf, path.len);
+                               dir_add_name(dir, istate, path.buf, path.len);
                        else if ((dir->flags & DIR_SHOW_IGNORED_TOO) ||
                                ((dir->flags & DIR_COLLECT_IGNORED) &&
                                exclude_matches_pathspec(path.buf, path.len,
-                                       simplify)))
-                               dir_add_ignored(dir, path.buf, path.len);
+                                                        pathspec)))
+                               dir_add_ignored(dir, istate, path.buf, path.len);
                        break;
 
                case path_untracked:
                        if (dir->flags & DIR_SHOW_IGNORED)
                                break;
-                       dir_add_name(dir, path.buf, path.len);
+                       dir_add_name(dir, istate, path.buf, path.len);
                        if (cdir.fdir)
                                add_untracked(untracked, path.buf + baselen);
                        break;
@@ -1766,7 +2031,7 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
        return dir_state;
 }
 
-static int cmp_name(const void *p1, const void *p2)
+int cmp_dir_entry(const void *p1, const void *p2)
 {
        const struct dir_entry *e1 = *(const struct dir_entry **)p1;
        const struct dir_entry *e2 = *(const struct dir_entry **)p2;
@@ -1774,36 +2039,18 @@ static int cmp_name(const void *p1, const void *p2)
        return name_compare(e1->name, e1->len, e2->name, e2->len);
 }
 
-static struct path_simplify *create_simplify(const char **pathspec)
-{
-       int nr, alloc = 0;
-       struct path_simplify *simplify = NULL;
-
-       if (!pathspec)
-               return NULL;
-
-       for (nr = 0 ; ; nr++) {
-               const char *match;
-               ALLOC_GROW(simplify, nr + 1, alloc);
-               match = *pathspec++;
-               if (!match)
-                       break;
-               simplify[nr].path = match;
-               simplify[nr].len = simple_length(match);
-       }
-       simplify[nr].path = NULL;
-       simplify[nr].len = 0;
-       return simplify;
-}
-
-static void free_simplify(struct path_simplify *simplify)
+/* check if *out lexically strictly contains *in */
+int check_dir_entry_contains(const struct dir_entry *out, const struct dir_entry *in)
 {
-       free(simplify);
+       return (out->len < in->len) &&
+               (out->name[out->len - 1] == '/') &&
+               !memcmp(out->name, in->name, out->len);
 }
 
 static int treat_leading_path(struct dir_struct *dir,
+                             struct index_state *istate,
                              const char *path, int len,
-                             const struct path_simplify *simplify)
+                             const struct pathspec *pathspec)
 {
        struct strbuf sb = STRBUF_INIT;
        int baselen, rc = 0;
@@ -1827,9 +2074,9 @@ static int treat_leading_path(struct dir_struct *dir,
                strbuf_add(&sb, path, baselen);
                if (!is_directory(sb.buf))
                        break;
-               if (simplify_away(sb.buf, sb.len, simplify))
+               if (simplify_away(sb.buf, sb.len, pathspec))
                        break;
-               if (treat_one_path(dir, NULL, &sb, baselen, simplify,
+               if (treat_one_path(dir, NULL, istate, &sb, baselen, pathspec,
                                   DT_DIR, NULL) == path_none)
                        break; /* do not recurse into it */
                if (len <= baselen) {
@@ -1851,31 +2098,67 @@ static const char *get_ident_string(void)
                return sb.buf;
        if (uname(&uts) < 0)
                die_errno(_("failed to get kernel name and information"));
-       strbuf_addf(&sb, "Location %s, system %s %s %s", get_git_work_tree(),
-                   uts.sysname, uts.release, uts.version);
+       strbuf_addf(&sb, "Location %s, system %s", get_git_work_tree(),
+                   uts.sysname);
        return sb.buf;
 }
 
 static int ident_in_untracked(const struct untracked_cache *uc)
 {
-       const char *end = uc->ident.buf + uc->ident.len;
-       const char *p   = uc->ident.buf;
+       /*
+        * Previous git versions may have saved many NUL separated
+        * strings in the "ident" field, but it is insane to manage
+        * many locations, so just take care of the first one.
+        */
 
-       for (p = uc->ident.buf; p < end; p += strlen(p) + 1)
-               if (!strcmp(p, get_ident_string()))
-                       return 1;
-       return 0;
+       return !strcmp(uc->ident.buf, get_ident_string());
 }
 
-void add_untracked_ident(struct untracked_cache *uc)
+static void set_untracked_ident(struct untracked_cache *uc)
 {
-       if (ident_in_untracked(uc))
-               return;
+       strbuf_reset(&uc->ident);
        strbuf_addstr(&uc->ident, get_ident_string());
-       /* this strbuf contains a list of strings, save NUL too */
+
+       /*
+        * This strbuf used to contain a list of NUL separated
+        * strings, so save NUL too for backward compatibility.
+        */
        strbuf_addch(&uc->ident, 0);
 }
 
+static void new_untracked_cache(struct index_state *istate)
+{
+       struct untracked_cache *uc = xcalloc(1, sizeof(*uc));
+       strbuf_init(&uc->ident, 100);
+       uc->exclude_per_dir = ".gitignore";
+       /* should be the same flags used by git-status */
+       uc->dir_flags = DIR_SHOW_OTHER_DIRECTORIES | DIR_HIDE_EMPTY_DIRECTORIES;
+       set_untracked_ident(uc);
+       istate->untracked = uc;
+       istate->cache_changed |= UNTRACKED_CHANGED;
+}
+
+void add_untracked_cache(struct index_state *istate)
+{
+       if (!istate->untracked) {
+               new_untracked_cache(istate);
+       } else {
+               if (!ident_in_untracked(istate->untracked)) {
+                       free_untracked_cache(istate->untracked);
+                       new_untracked_cache(istate);
+               }
+       }
+}
+
+void remove_untracked_cache(struct index_state *istate)
+{
+       if (istate->untracked) {
+               free_untracked_cache(istate->untracked);
+               istate->untracked = NULL;
+               istate->cache_changed |= UNTRACKED_CHANGED;
+       }
+}
+
 static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *dir,
                                                      int base_len,
                                                      const struct pathspec *pathspec)
@@ -1933,7 +2216,7 @@ static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *d
                return NULL;
 
        if (!ident_in_untracked(dir->untracked)) {
-               warning(_("Untracked cache is disabled on this system."));
+               warning(_("Untracked cache is disabled on this system or location."));
                return NULL;
        }
 
@@ -1961,33 +2244,14 @@ static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *d
        return root;
 }
 
-int read_directory(struct dir_struct *dir, const char *path, int len, const struct pathspec *pathspec)
+int read_directory(struct dir_struct *dir, struct index_state *istate,
+                  const char *path, int len, const struct pathspec *pathspec)
 {
-       struct path_simplify *simplify;
        struct untracked_cache_dir *untracked;
 
-       /*
-        * Check out create_simplify()
-        */
-       if (pathspec)
-               GUARD_PATHSPEC(pathspec,
-                              PATHSPEC_FROMTOP |
-                              PATHSPEC_MAXDEPTH |
-                              PATHSPEC_LITERAL |
-                              PATHSPEC_GLOB |
-                              PATHSPEC_ICASE |
-                              PATHSPEC_EXCLUDE);
-
        if (has_symlink_leading_path(path, len))
                return dir->nr;
 
-       /*
-        * exclude patterns are treated like positive ones in
-        * create_simplify. Usually exclude patterns should be a
-        * subset of positive ones, which has no impacts on
-        * create_simplify().
-        */
-       simplify = create_simplify(pathspec ? pathspec->_raw : NULL);
        untracked = validate_untracked_cache(dir, len, pathspec);
        if (!untracked)
                /*
@@ -1995,11 +2259,33 @@ int read_directory(struct dir_struct *dir, const char *path, int len, const stru
                 * e.g. prep_exclude()
                 */
                dir->untracked = NULL;
-       if (!len || treat_leading_path(dir, path, len, simplify))
-               read_directory_recursive(dir, path, len, untracked, 0, simplify);
-       free_simplify(simplify);
-       qsort(dir->entries, dir->nr, sizeof(struct dir_entry *), cmp_name);
-       qsort(dir->ignored, dir->ignored_nr, sizeof(struct dir_entry *), cmp_name);
+       if (!len || treat_leading_path(dir, istate, path, len, pathspec))
+               read_directory_recursive(dir, istate, path, len, untracked, 0, 0, pathspec);
+       QSORT(dir->entries, dir->nr, cmp_dir_entry);
+       QSORT(dir->ignored, dir->ignored_nr, cmp_dir_entry);
+
+       /*
+        * If DIR_SHOW_IGNORED_TOO is set, read_directory_recursive() will
+        * also pick up untracked contents of untracked dirs; by default
+        * we discard these, but given DIR_KEEP_UNTRACKED_CONTENTS we do not.
+        */
+       if ((dir->flags & DIR_SHOW_IGNORED_TOO) &&
+                    !(dir->flags & DIR_KEEP_UNTRACKED_CONTENTS)) {
+               int i, j;
+
+               /* remove from dir->entries untracked contents of untracked dirs */
+               for (i = j = 0; j < dir->nr; j++) {
+                       if (i &&
+                           check_dir_entry_contains(dir->entries[i - 1], dir->entries[j])) {
+                               FREE_AND_NULL(dir->entries[j]);
+                       } else {
+                               dir->entries[i++] = dir->entries[j];
+                       }
+               }
+
+               dir->nr = i;
+       }
+
        if (dir->untracked) {
                static struct trace_key trace_untracked_stats = TRACE_KEY_INIT(UNTRACKED_STATS);
                trace_printf_key(&trace_untracked_stats,
@@ -2011,14 +2297,13 @@ int read_directory(struct dir_struct *dir, const char *path, int len, const stru
                                 dir->untracked->gitignore_invalidated,
                                 dir->untracked->dir_invalidated,
                                 dir->untracked->dir_opened);
-               if (dir->untracked == the_index.untracked &&
+               if (dir->untracked == istate->untracked &&
                    (dir->untracked->dir_opened ||
                     dir->untracked->gitignore_invalidated ||
                     dir->untracked->dir_invalidated))
-                       the_index.cache_changed |= UNTRACKED_CHANGED;
-               if (dir->untracked != the_index.untracked) {
-                       free(dir->untracked);
-                       dir->untracked = NULL;
+                       istate->cache_changed |= UNTRACKED_CHANGED;
+               if (dir->untracked != istate->untracked) {
+                       FREE_AND_NULL(dir->untracked);
                }
        }
        return dir->nr;
@@ -2030,6 +2315,15 @@ int file_exists(const char *f)
        return lstat(f, &sb) == 0;
 }
 
+static int cmp_icase(char a, char b)
+{
+       if (a == b)
+               return 0;
+       if (ignore_case)
+               return toupper(a) - toupper(b);
+       return a - b;
+}
+
 /*
  * Given two normalized paths (a trailing slash is ok), if subdir is
  * outside dir, return -1.  Otherwise return the offset in subdir that
@@ -2041,7 +2335,7 @@ int dir_inside_of(const char *subdir, const char *dir)
 
        assert(dir && subdir && *dir && *subdir);
 
-       while (*dir && *subdir && *dir == *subdir) {
+       while (*dir && *subdir && !cmp_icase(*dir, *subdir)) {
                dir++;
                subdir++;
                offset++;
@@ -2102,10 +2396,10 @@ static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up)
        int ret = 0, original_len = path->len, len, kept_down = 0;
        int only_empty = (flag & REMOVE_DIR_EMPTY_ONLY);
        int keep_toplevel = (flag & REMOVE_DIR_KEEP_TOPLEVEL);
-       unsigned char submodule_head[20];
+       struct object_id submodule_head;
 
        if ((flag & REMOVE_DIR_KEEP_NESTED_GIT) &&
-           !resolve_gitlink_ref(path->buf, "HEAD", submodule_head)) {
+           !resolve_gitlink_ref(path->buf, "HEAD", &submodule_head)) {
                /* Do not descend and nuke a nested git work tree. */
                if (kept_up)
                        *kept_up = 1;
@@ -2126,8 +2420,7 @@ static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up)
                else
                        return -1;
        }
-       if (path->buf[original_len - 1] != '/')
-               strbuf_addch(path, '/');
+       strbuf_complete(path, '/');
 
        len = path->len;
        while ((e = readdir(dir)) != NULL) {
@@ -2180,8 +2473,6 @@ static GIT_PATH_FUNC(git_path_info_exclude, "info/exclude")
 
 void setup_standard_excludes(struct dir_struct *dir)
 {
-       const char *path;
-
        dir->exclude_per_dir = ".gitignore";
 
        /* core.excludefile defaulting to $XDG_HOME/git/ignore */
@@ -2192,17 +2483,19 @@ void setup_standard_excludes(struct dir_struct *dir)
                                         dir->untracked ? &dir->ss_excludes_file : NULL);
 
        /* per repository user preference */
-       path = git_path_info_exclude();
-       if (!access_or_warn(path, R_OK, 0))
-               add_excludes_from_file_1(dir, path,
-                                        dir->untracked ? &dir->ss_info_exclude : NULL);
+       if (startup_info->have_repository) {
+               const char *path = git_path_info_exclude();
+               if (!access_or_warn(path, R_OK, 0))
+                       add_excludes_from_file_1(dir, path,
+                                                dir->untracked ? &dir->ss_info_exclude : NULL);
+       }
 }
 
 int remove_path(const char *name)
 {
        char *slash;
 
-       if (unlink(name) && errno != ENOENT && errno != ENOTDIR)
+       if (unlink(name) && !is_missing_file_error(errno))
                return -1;
 
        slash = strrchr(name, '/');
@@ -2257,7 +2550,8 @@ struct ondisk_untracked_cache {
        char exclude_per_dir[FLEX_ARRAY];
 };
 
-#define ouc_size(len) (offsetof(struct ondisk_untracked_cache, exclude_per_dir) + len + 1)
+#define ouc_offset(x) offsetof(struct ondisk_untracked_cache, x)
+#define ouc_size(len) (ouc_offset(exclude_per_dir) + len + 1)
 
 struct write_data {
        int index;         /* number of written untracked_cache_dir */
@@ -2338,24 +2632,22 @@ void write_untracked_extension(struct strbuf *out, struct untracked_cache *untra
        struct ondisk_untracked_cache *ouc;
        struct write_data wd;
        unsigned char varbuf[16];
-       int len = 0, varint_len;
-       if (untracked->exclude_per_dir)
-               len = strlen(untracked->exclude_per_dir);
-       ouc = xmalloc(sizeof(*ouc) + len + 1);
+       int varint_len;
+       size_t len = strlen(untracked->exclude_per_dir);
+
+       FLEX_ALLOC_MEM(ouc, exclude_per_dir, untracked->exclude_per_dir, len);
        stat_data_to_disk(&ouc->info_exclude_stat, &untracked->ss_info_exclude.stat);
        stat_data_to_disk(&ouc->excludes_file_stat, &untracked->ss_excludes_file.stat);
        hashcpy(ouc->info_exclude_sha1, untracked->ss_info_exclude.sha1);
        hashcpy(ouc->excludes_file_sha1, untracked->ss_excludes_file.sha1);
        ouc->dir_flags = htonl(untracked->dir_flags);
-       memcpy(ouc->exclude_per_dir, untracked->exclude_per_dir, len + 1);
 
        varint_len = encode_varint(untracked->ident.len, varbuf);
        strbuf_add(out, varbuf, varint_len);
-       strbuf_add(out, untracked->ident.buf, untracked->ident.len);
+       strbuf_addbuf(out, &untracked->ident);
 
        strbuf_add(out, ouc, ouc_size(len));
-       free(ouc);
-       ouc = NULL;
+       FREE_AND_NULL(ouc);
 
        if (!untracked->root) {
                varint_len = encode_varint(0, varbuf);
@@ -2421,17 +2713,18 @@ struct read_data {
        const unsigned char *end;
 };
 
-static void stat_data_from_disk(struct stat_data *to, const struct stat_data *from)
+static void stat_data_from_disk(struct stat_data *to, const unsigned char *data)
 {
-       to->sd_ctime.sec  = get_be32(&from->sd_ctime.sec);
-       to->sd_ctime.nsec = get_be32(&from->sd_ctime.nsec);
-       to->sd_mtime.sec  = get_be32(&from->sd_mtime.sec);
-       to->sd_mtime.nsec = get_be32(&from->sd_mtime.nsec);
-       to->sd_dev        = get_be32(&from->sd_dev);
-       to->sd_ino        = get_be32(&from->sd_ino);
-       to->sd_uid        = get_be32(&from->sd_uid);
-       to->sd_gid        = get_be32(&from->sd_gid);
-       to->sd_size       = get_be32(&from->sd_size);
+       memcpy(to, data, sizeof(*to));
+       to->sd_ctime.sec  = ntohl(to->sd_ctime.sec);
+       to->sd_ctime.nsec = ntohl(to->sd_ctime.nsec);
+       to->sd_mtime.sec  = ntohl(to->sd_mtime.sec);
+       to->sd_mtime.nsec = ntohl(to->sd_mtime.nsec);
+       to->sd_dev        = ntohl(to->sd_dev);
+       to->sd_ino        = ntohl(to->sd_ino);
+       to->sd_uid        = ntohl(to->sd_uid);
+       to->sd_gid        = ntohl(to->sd_gid);
+       to->sd_size       = ntohl(to->sd_size);
 }
 
 static int read_one_dir(struct untracked_cache_dir **untracked_,
@@ -2452,21 +2745,21 @@ static int read_one_dir(struct untracked_cache_dir **untracked_,
        ud.untracked_alloc = value;
        ud.untracked_nr    = value;
        if (ud.untracked_nr)
-               ud.untracked = xmalloc(sizeof(*ud.untracked) * ud.untracked_nr);
+               ALLOC_ARRAY(ud.untracked, ud.untracked_nr);
        data = next;
 
        next = data;
        ud.dirs_alloc = ud.dirs_nr = decode_varint(&next);
        if (next > end)
                return -1;
-       ud.dirs = xmalloc(sizeof(*ud.dirs) * ud.dirs_nr);
+       ALLOC_ARRAY(ud.dirs, ud.dirs_nr);
        data = next;
 
        len = strlen((const char *)data);
        next = data + len + 1;
        if (next > rd->end)
                return -1;
-       *untracked_ = untracked = xmalloc(sizeof(*untracked) + len);
+       *untracked_ = untracked = xmalloc(st_add(sizeof(*untracked), len));
        memcpy(untracked, &ud, sizeof(ud));
        memcpy(untracked->name, data, len + 1);
        data = next;
@@ -2506,7 +2799,7 @@ static void read_stat(size_t pos, void *cb)
                rd->data = rd->end + 1;
                return;
        }
-       stat_data_from_disk(&ud->stat_data, (struct stat_data *)rd->data);
+       stat_data_from_disk(&ud->stat_data, rd->data);
        rd->data += sizeof(struct stat_data);
        ud->valid = 1;
 }
@@ -2524,22 +2817,22 @@ static void read_sha1(size_t pos, void *cb)
 }
 
 static void load_sha1_stat(struct sha1_stat *sha1_stat,
-                          const struct stat_data *stat,
+                          const unsigned char *data,
                           const unsigned char *sha1)
 {
-       stat_data_from_disk(&sha1_stat->stat, stat);
+       stat_data_from_disk(&sha1_stat->stat, data);
        hashcpy(sha1_stat->sha1, sha1);
        sha1_stat->valid = 1;
 }
 
 struct untracked_cache *read_untracked_extension(const void *data, unsigned long sz)
 {
-       const struct ondisk_untracked_cache *ouc;
        struct untracked_cache *uc;
        struct read_data rd;
        const unsigned char *next = data, *end = (const unsigned char *)data + sz;
        const char *ident;
        int ident_len, len;
+       const char *exclude_per_dir;
 
        if (sz <= 1 || end[-1] != '\0')
                return NULL;
@@ -2551,21 +2844,23 @@ struct untracked_cache *read_untracked_extension(const void *data, unsigned long
        ident = (const char *)next;
        next += ident_len;
 
-       ouc = (const struct ondisk_untracked_cache *)next;
        if (next + ouc_size(0) > end)
                return NULL;
 
        uc = xcalloc(1, sizeof(*uc));
        strbuf_init(&uc->ident, ident_len);
        strbuf_add(&uc->ident, ident, ident_len);
-       load_sha1_stat(&uc->ss_info_exclude, &ouc->info_exclude_stat,
-                      ouc->info_exclude_sha1);
-       load_sha1_stat(&uc->ss_excludes_file, &ouc->excludes_file_stat,
-                      ouc->excludes_file_sha1);
-       uc->dir_flags = get_be32(&ouc->dir_flags);
-       uc->exclude_per_dir = xstrdup(ouc->exclude_per_dir);
+       load_sha1_stat(&uc->ss_info_exclude,
+                      next + ouc_offset(info_exclude_stat),
+                      next + ouc_offset(info_exclude_sha1));
+       load_sha1_stat(&uc->ss_excludes_file,
+                      next + ouc_offset(excludes_file_stat),
+                      next + ouc_offset(excludes_file_sha1));
+       uc->dir_flags = get_be32(next + ouc_offset(dir_flags));
+       exclude_per_dir = (const char *)next + ouc_offset(exclude_per_dir);
+       uc->exclude_per_dir = xstrdup(exclude_per_dir);
        /* NUL after exclude_per_dir is covered by sizeof(*ouc) */
-       next += ouc_size(strlen(ouc->exclude_per_dir));
+       next += ouc_size(strlen(exclude_per_dir));
        if (next >= end)
                goto done2;
 
@@ -2579,7 +2874,7 @@ struct untracked_cache *read_untracked_extension(const void *data, unsigned long
        rd.data       = next;
        rd.end        = end;
        rd.index      = 0;
-       rd.ucd        = xmalloc(sizeof(*rd.ucd) * len);
+       ALLOC_ARRAY(rd.ucd, len);
 
        if (read_one_dir(&uc->root, &rd) || rd.index != len)
                goto done;
@@ -2692,3 +2987,50 @@ void untracked_cache_add_to_index(struct index_state *istate,
 {
        untracked_cache_invalidate_path(istate, path);
 }
+
+/* Update gitfile and core.worktree setting to connect work tree and git dir */
+void connect_work_tree_and_git_dir(const char *work_tree_, const char *git_dir_)
+{
+       struct strbuf gitfile_sb = STRBUF_INIT;
+       struct strbuf cfg_sb = STRBUF_INIT;
+       struct strbuf rel_path = STRBUF_INIT;
+       char *git_dir, *work_tree;
+
+       /* Prepare .git file */
+       strbuf_addf(&gitfile_sb, "%s/.git", work_tree_);
+       if (safe_create_leading_directories_const(gitfile_sb.buf))
+               die(_("could not create directories for %s"), gitfile_sb.buf);
+
+       /* Prepare config file */
+       strbuf_addf(&cfg_sb, "%s/config", git_dir_);
+       if (safe_create_leading_directories_const(cfg_sb.buf))
+               die(_("could not create directories for %s"), cfg_sb.buf);
+
+       git_dir = real_pathdup(git_dir_, 1);
+       work_tree = real_pathdup(work_tree_, 1);
+
+       /* Write .git file */
+       write_file(gitfile_sb.buf, "gitdir: %s",
+                  relative_path(git_dir, work_tree, &rel_path));
+       /* Update core.worktree setting */
+       git_config_set_in_file(cfg_sb.buf, "core.worktree",
+                              relative_path(work_tree, git_dir, &rel_path));
+
+       strbuf_release(&gitfile_sb);
+       strbuf_release(&cfg_sb);
+       strbuf_release(&rel_path);
+       free(work_tree);
+       free(git_dir);
+}
+
+/*
+ * Migrate the git directory of the given path from old_git_dir to new_git_dir.
+ */
+void relocate_gitdir(const char *path, const char *old_git_dir, const char *new_git_dir)
+{
+       if (rename(old_git_dir, new_git_dir) < 0)
+               die_errno(_("could not migrate git directory from '%s' to '%s'"),
+                       old_git_dir, new_git_dir);
+
+       connect_work_tree_and_git_dir(path, new_git_dir);
+}