Imported Upstream version 2.14.3
[platform/upstream/git.git] / combine-diff.c
index bb1cc96..9e163d5 100644 (file)
@@ -5,19 +5,30 @@
 #include "diffcore.h"
 #include "quote.h"
 #include "xdiff-interface.h"
+#include "xdiff/xmacros.h"
 #include "log-tree.h"
 #include "refs.h"
 #include "userdiff.h"
 #include "sha1-array.h"
+#include "revision.h"
+
+static int compare_paths(const struct combine_diff_path *one,
+                         const struct diff_filespec *two)
+{
+       if (!S_ISDIR(one->mode) && !S_ISDIR(two->mode))
+               return strcmp(one->path, two->path);
+
+       return base_name_compare(one->path, strlen(one->path), one->mode,
+                                two->path, strlen(two->path), two->mode);
+}
 
 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
-       struct combine_diff_path *p;
-       int i;
+       struct combine_diff_path *p, **tail = &curr;
+       int i, cmp;
 
        if (!n) {
-               struct combine_diff_path *list = NULL, **tail = &list;
                for (i = 0; i < q->nr; i++) {
                        int len;
                        const char *path;
@@ -29,60 +40,73 @@ static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr,
                        p->path = (char *) &(p->parent[num_parent]);
                        memcpy(p->path, path, len);
                        p->path[len] = 0;
-                       p->len = len;
                        p->next = NULL;
                        memset(p->parent, 0,
                               sizeof(p->parent[0]) * num_parent);
 
-                       hashcpy(p->sha1, q->queue[i]->two->sha1);
+                       oidcpy(&p->oid, &q->queue[i]->two->oid);
                        p->mode = q->queue[i]->two->mode;
-                       hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
+                       oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
                        p->parent[n].mode = q->queue[i]->one->mode;
                        p->parent[n].status = q->queue[i]->status;
                        *tail = p;
                        tail = &p->next;
                }
-               return list;
+               return curr;
        }
 
-       for (p = curr; p; p = p->next) {
-               int found = 0;
-               if (!p->len)
+       /*
+        * paths in curr (linked list) and q->queue[] (array) are
+        * both sorted in the tree order.
+        */
+       i = 0;
+       while ((p = *tail) != NULL) {
+               cmp = ((i >= q->nr)
+                      ? -1 : compare_paths(p, q->queue[i]->two));
+
+               if (cmp < 0) {
+                       /* p->path not in q->queue[]; drop it */
+                       *tail = p->next;
+                       free(p);
                        continue;
-               for (i = 0; i < q->nr; i++) {
-                       const char *path;
-                       int len;
+               }
 
-                       if (diff_unmodified_pair(q->queue[i]))
-                               continue;
-                       path = q->queue[i]->two->path;
-                       len = strlen(path);
-                       if (len == p->len && !memcmp(path, p->path, len)) {
-                               found = 1;
-                               hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
-                               p->parent[n].mode = q->queue[i]->one->mode;
-                               p->parent[n].status = q->queue[i]->status;
-                               break;
-                       }
+               if (cmp > 0) {
+                       /* q->queue[i] not in p->path; skip it */
+                       i++;
+                       continue;
                }
-               if (!found)
-                       p->len = 0;
+
+               oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
+               p->parent[n].mode = q->queue[i]->one->mode;
+               p->parent[n].status = q->queue[i]->status;
+
+               tail = &p->next;
+               i++;
        }
        return curr;
 }
 
 /* Lines lost from parent */
 struct lline {
-       struct lline *next;
+       struct lline *next, *prev;
        int len;
        unsigned long parent_map;
        char line[FLEX_ARRAY];
 };
 
+/* Lines lost from current parent (before coalescing) */
+struct plost {
+       struct lline *lost_head, *lost_tail;
+       int len;
+};
+
 /* Lines surviving in the merge result */
 struct sline {
-       struct lline *lost_head, **lost_tail;
-       struct lline *next_lost;
+       /* Accumulated and coalesced lost lines */
+       struct lline *lost;
+       int lenlost;
+       struct plost plost;
        char *bol;
        int len;
        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
@@ -94,7 +118,173 @@ struct sline {
        unsigned long *p_lno;
 };
 
-static char *grab_blob(const unsigned char *sha1, unsigned int mode,
+static int match_string_spaces(const char *line1, int len1,
+                              const char *line2, int len2,
+                              long flags)
+{
+       if (flags & XDF_WHITESPACE_FLAGS) {
+               for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
+               for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
+       }
+
+       if (!(flags & (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE)))
+               return (len1 == len2 && !memcmp(line1, line2, len1));
+
+       while (len1 > 0 && len2 > 0) {
+               len1--;
+               len2--;
+               if (XDL_ISSPACE(line1[len1]) || XDL_ISSPACE(line2[len2])) {
+                       if ((flags & XDF_IGNORE_WHITESPACE_CHANGE) &&
+                           (!XDL_ISSPACE(line1[len1]) || !XDL_ISSPACE(line2[len2])))
+                               return 0;
+
+                       for (; len1 > 0 && XDL_ISSPACE(line1[len1]); len1--);
+                       for (; len2 > 0 && XDL_ISSPACE(line2[len2]); len2--);
+               }
+               if (line1[len1] != line2[len2])
+                       return 0;
+       }
+
+       if (flags & XDF_IGNORE_WHITESPACE) {
+               /* Consume remaining spaces */
+               for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
+               for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
+       }
+
+       /* We matched full line1 and line2 */
+       if (!len1 && !len2)
+               return 1;
+
+       return 0;
+}
+
+enum coalesce_direction { MATCH, BASE, NEW };
+
+/* Coalesce new lines into base by finding LCS */
+static struct lline *coalesce_lines(struct lline *base, int *lenbase,
+                                   struct lline *new, int lennew,
+                                   unsigned long parent, long flags)
+{
+       int **lcs;
+       enum coalesce_direction **directions;
+       struct lline *baseend, *newend = NULL;
+       int i, j, origbaselen = *lenbase;
+
+       if (new == NULL)
+               return base;
+
+       if (base == NULL) {
+               *lenbase = lennew;
+               return new;
+       }
+
+       /*
+        * Coalesce new lines into base by finding the LCS
+        * - Create the table to run dynamic programming
+        * - Compute the LCS
+        * - Then reverse read the direction structure:
+        *   - If we have MATCH, assign parent to base flag, and consume
+        *   both baseend and newend
+        *   - Else if we have BASE, consume baseend
+        *   - Else if we have NEW, insert newend lline into base and
+        *   consume newend
+        */
+       lcs = xcalloc(st_add(origbaselen, 1), sizeof(int*));
+       directions = xcalloc(st_add(origbaselen, 1), sizeof(enum coalesce_direction*));
+       for (i = 0; i < origbaselen + 1; i++) {
+               lcs[i] = xcalloc(st_add(lennew, 1), sizeof(int));
+               directions[i] = xcalloc(st_add(lennew, 1), sizeof(enum coalesce_direction));
+               directions[i][0] = BASE;
+       }
+       for (j = 1; j < lennew + 1; j++)
+               directions[0][j] = NEW;
+
+       for (i = 1, baseend = base; i < origbaselen + 1; i++) {
+               for (j = 1, newend = new; j < lennew + 1; j++) {
+                       if (match_string_spaces(baseend->line, baseend->len,
+                                               newend->line, newend->len, flags)) {
+                               lcs[i][j] = lcs[i - 1][j - 1] + 1;
+                               directions[i][j] = MATCH;
+                       } else if (lcs[i][j - 1] >= lcs[i - 1][j]) {
+                               lcs[i][j] = lcs[i][j - 1];
+                               directions[i][j] = NEW;
+                       } else {
+                               lcs[i][j] = lcs[i - 1][j];
+                               directions[i][j] = BASE;
+                       }
+                       if (newend->next)
+                               newend = newend->next;
+               }
+               if (baseend->next)
+                       baseend = baseend->next;
+       }
+
+       for (i = 0; i < origbaselen + 1; i++)
+               free(lcs[i]);
+       free(lcs);
+
+       /* At this point, baseend and newend point to the end of each lists */
+       i--;
+       j--;
+       while (i != 0 || j != 0) {
+               if (directions[i][j] == MATCH) {
+                       baseend->parent_map |= 1<<parent;
+                       baseend = baseend->prev;
+                       newend = newend->prev;
+                       i--;
+                       j--;
+               } else if (directions[i][j] == NEW) {
+                       struct lline *lline;
+
+                       lline = newend;
+                       /* Remove lline from new list and update newend */
+                       if (lline->prev)
+                               lline->prev->next = lline->next;
+                       else
+                               new = lline->next;
+                       if (lline->next)
+                               lline->next->prev = lline->prev;
+
+                       newend = lline->prev;
+                       j--;
+
+                       /* Add lline to base list */
+                       if (baseend) {
+                               lline->next = baseend->next;
+                               lline->prev = baseend;
+                               if (lline->prev)
+                                       lline->prev->next = lline;
+                       }
+                       else {
+                               lline->next = base;
+                               base = lline;
+                       }
+                       (*lenbase)++;
+
+                       if (lline->next)
+                               lline->next->prev = lline;
+
+               } else {
+                       baseend = baseend->prev;
+                       i--;
+               }
+       }
+
+       newend = new;
+       while (newend) {
+               struct lline *lline = newend;
+               newend = newend->next;
+               free(lline);
+       }
+
+       for (i = 0; i < origbaselen + 1; i++)
+               free(directions[i]);
+       free(directions);
+
+       return base;
+}
+
+static char *grab_blob(const struct object_id *oid, unsigned int mode,
                       unsigned long *size, struct userdiff_driver *textconv,
                       const char *path)
 {
@@ -102,22 +292,23 @@ static char *grab_blob(const unsigned char *sha1, unsigned int mode,
        enum object_type type;
 
        if (S_ISGITLINK(mode)) {
-               blob = xmalloc(100);
-               *size = snprintf(blob, 100,
-                                "Subproject commit %s\n", sha1_to_hex(sha1));
-       } else if (is_null_sha1(sha1)) {
+               struct strbuf buf = STRBUF_INIT;
+               strbuf_addf(&buf, "Subproject commit %s\n", oid_to_hex(oid));
+               *size = buf.len;
+               blob = strbuf_detach(&buf, NULL);
+       } else if (is_null_oid(oid)) {
                /* deleted blob */
                *size = 0;
                return xcalloc(1, 1);
        } else if (textconv) {
                struct diff_filespec *df = alloc_filespec(path);
-               fill_filespec(df, sha1, 1, mode);
+               fill_filespec(df, oid, 1, mode);
                *size = fill_textconv(textconv, df, &blob);
                free_filespec(df);
        } else {
-               blob = read_sha1_file(sha1, &type, size);
+               blob = read_sha1_file(oid->hash, &type, size);
                if (type != OBJ_BLOB)
-                       die("object '%s' is not a blob!", sha1_to_hex(sha1));
+                       die("object '%s' is not a blob!", oid_to_hex(oid));
        }
        return blob;
 }
@@ -129,29 +320,17 @@ static void append_lost(struct sline *sline, int n, const char *line, int len)
        if (line[len-1] == '\n')
                len--;
 
-       /* Check to see if we can squash things */
-       if (sline->lost_head) {
-               lline = sline->next_lost;
-               while (lline) {
-                       if (lline->len == len &&
-                           !memcmp(lline->line, line, len)) {
-                               lline->parent_map |= this_mask;
-                               sline->next_lost = lline->next;
-                               return;
-                       }
-                       lline = lline->next;
-               }
-       }
-
-       lline = xmalloc(sizeof(*lline) + len + 1);
+       FLEX_ALLOC_MEM(lline, line, line, len);
        lline->len = len;
        lline->next = NULL;
+       lline->prev = sline->plost.lost_tail;
+       if (lline->prev)
+               lline->prev->next = lline;
+       else
+               sline->plost.lost_head = lline;
+       sline->plost.lost_tail = lline;
+       sline->plost.len++;
        lline->parent_map = this_mask;
-       memcpy(lline->line, line, len);
-       lline->line[len] = 0;
-       *sline->lost_tail = lline;
-       sline->lost_tail = &lline->next;
-       sline->next_lost = NULL;
 }
 
 struct combine_diff_state {
@@ -194,7 +373,6 @@ static void consume_line(void *state_, char *line, unsigned long len)
                                xcalloc(state->num_parent,
                                        sizeof(unsigned long));
                state->sline[state->nb-1].p_lno[state->n] = state->ob;
-               state->lost_bucket->next_lost = state->lost_bucket->lost_head;
                return;
        }
        if (!state->lost_bucket)
@@ -210,12 +388,12 @@ static void consume_line(void *state_, char *line, unsigned long len)
        }
 }
 
-static void combine_diff(const unsigned char *parent, unsigned int mode,
+static void combine_diff(const struct object_id *parent, unsigned int mode,
                         mmfile_t *result_file,
                         struct sline *sline, unsigned int cnt, int n,
                         int num_parent, int result_deleted,
                         struct userdiff_driver *textconv,
-                        const char *path)
+                        const char *path, long flags)
 {
        unsigned int p_lno, lno;
        unsigned long nmask = (1UL << n);
@@ -231,7 +409,7 @@ static void combine_diff(const unsigned char *parent, unsigned int mode,
        parent_file.ptr = grab_blob(parent, mode, &sz, textconv, path);
        parent_file.size = sz;
        memset(&xpp, 0, sizeof(xpp));
-       xpp.flags = 0;
+       xpp.flags = flags;
        memset(&xecfg, 0, sizeof(xecfg));
        memset(&state, 0, sizeof(state));
        state.nmask = nmask;
@@ -240,8 +418,10 @@ static void combine_diff(const unsigned char *parent, unsigned int mode,
        state.num_parent = num_parent;
        state.n = n;
 
-       xdi_diff_outf(&parent_file, result_file, consume_line, &state,
-                     &xpp, &xecfg);
+       if (xdi_diff_outf(&parent_file, result_file, consume_line, &state,
+                         &xpp, &xecfg))
+               die("unable to generate combined diff for %s",
+                   oid_to_hex(parent));
        free(parent_file.ptr);
 
        /* Assign line numbers for this parent.
@@ -255,8 +435,18 @@ static void combine_diff(const unsigned char *parent, unsigned int mode,
                struct lline *ll;
                sline[lno].p_lno[n] = p_lno;
 
+               /* Coalesce new lines */
+               if (sline[lno].plost.lost_head) {
+                       struct sline *sl = &sline[lno];
+                       sl->lost = coalesce_lines(sl->lost, &sl->lenlost,
+                                                 sl->plost.lost_head,
+                                                 sl->plost.len, n, flags);
+                       sl->plost.lost_head = sl->plost.lost_tail = NULL;
+                       sl->plost.len = 0;
+               }
+
                /* How many lines would this sline advance the p_lno? */
-               ll = sline[lno].lost_head;
+               ll = sline[lno].lost;
                while (ll) {
                        if (ll->parent_map & nmask)
                                p_lno++; /* '-' means parent had it */
@@ -276,7 +466,7 @@ static int interesting(struct sline *sline, unsigned long all_mask)
        /* If some parents lost lines here, or if we have added to
         * some parent, it is interesting.
         */
-       return ((sline->flag & all_mask) || sline->lost_head);
+       return ((sline->flag & all_mask) || sline->lost);
 }
 
 static unsigned long adjust_hunk_tail(struct sline *sline,
@@ -344,8 +534,11 @@ static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
                unsigned long k;
 
                /* Paint a few lines before the first interesting line. */
-               while (j < i)
-                       sline[j++].flag |= mark | no_pre_delete;
+               while (j < i) {
+                       if (!(sline[j].flag & mark))
+                               sline[j].flag |= no_pre_delete;
+                       sline[j++].flag |= mark;
+               }
 
        again:
                /* we know up to i is to be included.  where does the
@@ -459,7 +652,7 @@ static int make_hunks(struct sline *sline, unsigned long cnt,
                has_interesting = 0;
                for (j = i; j < hunk_end && !has_interesting; j++) {
                        unsigned long this_diff = sline[j].flag & all_mask;
-                       struct lline *ll = sline[j].lost_head;
+                       struct lline *ll = sline[j].lost;
                        if (this_diff) {
                                /* This has some changes.  Is it the
                                 * same as others?
@@ -526,7 +719,8 @@ static void show_line_to_eol(const char *line, int len, const char *reset)
               saw_cr_at_eol ? "\r" : "");
 }
 
-static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
+static void dump_sline(struct sline *sline, const char *line_prefix,
+                      unsigned long cnt, int num_parent,
                       int use_color, int result_deleted)
 {
        unsigned long mark = (1UL<<num_parent);
@@ -537,7 +731,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
        const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
-       const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
+       const char *c_context = diff_get_color(use_color, DIFF_CONTEXT);
        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 
        if (result_deleted)
@@ -582,7 +776,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
                        rlines -= null_context;
                }
 
-               fputs(c_frag, stdout);
+               printf("%s%s", line_prefix, c_frag);
                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
                for (i = 0; i < num_parent; i++)
                        show_parent_lno(sline, lno, hunk_end, i, null_context);
@@ -600,7 +794,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
                        }
                        if (comment_end)
                                printf("%s%s %s%s", c_reset,
-                                                   c_plain, c_reset,
+                                                   c_context, c_reset,
                                                    c_func);
                        for (i = 0; i < comment_end; i++)
                                putchar(hunk_comment[i]);
@@ -612,9 +806,9 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
                        int j;
                        unsigned long p_mask;
                        struct sline *sl = &sline[lno++];
-                       ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
+                       ll = (sl->flag & no_pre_delete) ? NULL : sl->lost;
                        while (ll) {
-                               fputs(c_old, stdout);
+                               printf("%s%s", line_prefix, c_old);
                                for (j = 0; j < num_parent; j++) {
                                        if (ll->parent_map & (1UL<<j))
                                                putchar('-');
@@ -627,6 +821,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
                        if (cnt < lno)
                                break;
                        p_mask = 1;
+                       fputs(line_prefix, stdout);
                        if (!(sl->flag & (mark-1))) {
                                /*
                                 * This sline was here to hang the
@@ -634,7 +829,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
                                 */
                                if (!context)
                                        continue;
-                               fputs(c_plain, stdout);
+                               fputs(c_context, stdout);
                        }
                        else
                                fputs(c_new, stdout);
@@ -662,7 +857,7 @@ static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
        jmask = (1UL<<j);
 
        for (lno = 0; lno <= cnt; lno++) {
-               struct lline *ll = sline->lost_head;
+               struct lline *ll = sline->lost;
                sline->p_lno[i] = sline->p_lno[j];
                while (ll) {
                        if (ll->parent_map & jmask)
@@ -680,11 +875,13 @@ static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 static void dump_quoted_path(const char *head,
                             const char *prefix,
                             const char *path,
+                            const char *line_prefix,
                             const char *c_meta, const char *c_reset)
 {
        static struct strbuf buf = STRBUF_INIT;
 
        strbuf_reset(&buf);
+       strbuf_addstr(&buf, line_prefix);
        strbuf_addstr(&buf, c_meta);
        strbuf_addstr(&buf, head);
        quote_two_c_style(&buf, prefix, path, 0);
@@ -696,11 +893,12 @@ static void show_combined_header(struct combine_diff_path *elem,
                                 int num_parent,
                                 int dense,
                                 struct rev_info *rev,
+                                const char *line_prefix,
                                 int mode_differs,
                                 int show_file_header)
 {
        struct diff_options *opt = &rev->diffopt;
-       int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
+       int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? GIT_SHA1_HEXSZ : DEFAULT_ABBREV;
        const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
        const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
        const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
@@ -714,14 +912,14 @@ static void show_combined_header(struct combine_diff_path *elem,
                show_log(rev);
 
        dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
-                        "", elem->path, c_meta, c_reset);
-       printf("%sindex ", c_meta);
+                        "", elem->path, line_prefix, c_meta, c_reset);
+       printf("%s%sindex ", line_prefix, c_meta);
        for (i = 0; i < num_parent; i++) {
-               abb = find_unique_abbrev(elem->parent[i].sha1,
+               abb = find_unique_abbrev(elem->parent[i].oid.hash,
                                         abbrev);
                printf("%s%s", i ? "," : "", abb);
        }
-       abb = find_unique_abbrev(elem->sha1, abbrev);
+       abb = find_unique_abbrev(elem->oid.hash, abbrev);
        printf("..%s%s\n", abb, c_reset);
 
        if (mode_differs) {
@@ -734,11 +932,12 @@ static void show_combined_header(struct combine_diff_path *elem,
                            DIFF_STATUS_ADDED)
                                added = 0;
                if (added)
-                       printf("%snew file mode %06o",
-                              c_meta, elem->mode);
+                       printf("%s%snew file mode %06o",
+                              line_prefix, c_meta, elem->mode);
                else {
                        if (deleted)
-                               printf("%sdeleted file ", c_meta);
+                               printf("%s%sdeleted file ",
+                                      line_prefix, c_meta);
                        printf("mode ");
                        for (i = 0; i < num_parent; i++) {
                                printf("%s%06o", i ? "," : "",
@@ -755,16 +954,16 @@ static void show_combined_header(struct combine_diff_path *elem,
 
        if (added)
                dump_quoted_path("--- ", "", "/dev/null",
-                                c_meta, c_reset);
+                                line_prefix, c_meta, c_reset);
        else
                dump_quoted_path("--- ", a_prefix, elem->path,
-                                c_meta, c_reset);
+                                line_prefix, c_meta, c_reset);
        if (deleted)
                dump_quoted_path("+++ ", "", "/dev/null",
-                                c_meta, c_reset);
+                                line_prefix, c_meta, c_reset);
        else
                dump_quoted_path("+++ ", b_prefix, elem->path,
-                                c_meta, c_reset);
+                                line_prefix, c_meta, c_reset);
 }
 
 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
@@ -782,6 +981,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
        struct userdiff_driver *userdiff;
        struct userdiff_driver *textconv = NULL;
        int is_binary;
+       const char *line_prefix = diff_line_prefix(opt);
 
        context = opt->context;
        userdiff = userdiff_find_by_path(elem->path);
@@ -792,7 +992,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 
        /* Read the result of merge first */
        if (!working_tree_file)
-               result = grab_blob(elem->sha1, elem->mode, &result_size,
+               result = grab_blob(&elem->oid, elem->mode, &result_size,
                                   textconv, elem->path);
        else {
                /* Used by diff-tree to read from the working tree */
@@ -806,24 +1006,23 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
                        struct strbuf buf = STRBUF_INIT;
 
                        if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
-                               error("readlink(%s): %s", elem->path,
-                                     strerror(errno));
+                               error_errno("readlink(%s)", elem->path);
                                return;
                        }
                        result_size = buf.len;
                        result = strbuf_detach(&buf, NULL);
                        elem->mode = canon_mode(st.st_mode);
                } else if (S_ISDIR(st.st_mode)) {
-                       unsigned char sha1[20];
-                       if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
-                               result = grab_blob(elem->sha1, elem->mode,
+                       struct object_id oid;
+                       if (resolve_gitlink_ref(elem->path, "HEAD", oid.hash) < 0)
+                               result = grab_blob(&elem->oid, elem->mode,
                                                   &result_size, NULL, NULL);
                        else
-                               result = grab_blob(sha1, elem->mode,
+                               result = grab_blob(&oid, elem->mode,
                                                   &result_size, NULL, NULL);
                } else if (textconv) {
                        struct diff_filespec *df = alloc_filespec(elem->path);
-                       fill_filespec(df, null_sha1, 0, st.st_mode);
+                       fill_filespec(df, &null_oid, 0, st.st_mode);
                        result_size = fill_textconv(textconv, df, &result);
                        free_filespec(df);
                } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
@@ -842,7 +1041,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
                                elem->mode = canon_mode(S_IFLNK);
 
                        result_size = len;
-                       result = xmalloc(len + 1);
+                       result = xmallocz(len);
 
                        done = read_in_full(fd, result, len);
                        if (done < 0)
@@ -850,13 +1049,11 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
                        else if (done < len)
                                die("early EOF '%s'", elem->path);
 
-                       result[len] = 0;
-
                        /* If not a fake symlink, apply filters, e.g. autocrlf */
                        if (is_file) {
                                struct strbuf buf = STRBUF_INIT;
 
-                               if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
+                               if (convert_to_git(&the_index, elem->path, result, len, &buf, safe_crlf)) {
                                        free(result);
                                        result = strbuf_detach(&buf, &len);
                                        result_size = len;
@@ -891,7 +1088,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
                for (i = 0; !is_binary && i < num_parent; i++) {
                        char *buf;
                        unsigned long size;
-                       buf = grab_blob(elem->parent[i].sha1,
+                       buf = grab_blob(&elem->parent[i].oid,
                                        elem->parent[i].mode,
                                        &size, NULL, NULL);
                        if (buffer_is_binary(buf, size))
@@ -901,7 +1098,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
        }
        if (is_binary) {
                show_combined_header(elem, num_parent, dense, rev,
-                                    mode_differs, 0);
+                                    line_prefix, mode_differs, 0);
                printf("Binary files differ\n");
                free(result);
                return;
@@ -914,12 +1111,8 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
        if (result_size && result[result_size-1] != '\n')
                cnt++; /* incomplete line */
 
-       sline = xcalloc(cnt+2, sizeof(*sline));
+       sline = xcalloc(st_add(cnt, 2), sizeof(*sline));
        sline[0].bol = result;
-       for (lno = 0; lno <= cnt + 1; lno++) {
-               sline[lno].lost_tail = &sline[lno].lost_head;
-               sline[lno].flag = 0;
-       }
        for (lno = 0, cp = result; cp < result + result_size; cp++) {
                if (*cp == '\n') {
                        sline[lno].len = cp - sline[lno].bol;
@@ -937,40 +1130,40 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
        /* Even p_lno[cnt+1] is valid -- that is for the end line number
         * for deletion hunk at the end.
         */
-       sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
+       sline[0].p_lno = xcalloc(st_mult(st_add(cnt, 2), num_parent), sizeof(unsigned long));
        for (lno = 0; lno <= cnt; lno++)
                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 
        for (i = 0; i < num_parent; i++) {
                int j;
                for (j = 0; j < i; j++) {
-                       if (!hashcmp(elem->parent[i].sha1,
-                                    elem->parent[j].sha1)) {
+                       if (!oidcmp(&elem->parent[i].oid,
+                                    &elem->parent[j].oid)) {
                                reuse_combine_diff(sline, cnt, i, j);
                                break;
                        }
                }
                if (i <= j)
-                       combine_diff(elem->parent[i].sha1,
+                       combine_diff(&elem->parent[i].oid,
                                     elem->parent[i].mode,
                                     &result_file, sline,
                                     cnt, i, num_parent, result_deleted,
-                                    textconv, elem->path);
+                                    textconv, elem->path, opt->xdl_opts);
        }
 
        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 
        if (show_hunks || mode_differs || working_tree_file) {
                show_combined_header(elem, num_parent, dense, rev,
-                                    mode_differs, 1);
-               dump_sline(sline, cnt, num_parent,
+                                    line_prefix, mode_differs, 1);
+               dump_sline(sline, line_prefix, cnt, num_parent,
                           opt->use_color, result_deleted);
        }
        free(result);
 
        for (lno = 0; lno < cnt; lno++) {
-               if (sline[lno].lost_head) {
-                       struct lline *ll = sline[lno].lost_head;
+               if (sline[lno].lost) {
+                       struct lline *ll = sline[lno].lost;
                        while (ll) {
                                struct lline *tmp = ll;
                                ll = ll->next;
@@ -982,14 +1175,11 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
        free(sline);
 }
 
-#define COLONS "::::::::::::::::::::::::::::::::"
-
 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 {
        struct diff_options *opt = &rev->diffopt;
-       int i, offset;
-       const char *prefix;
-       int line_termination, inter_name_termination;
+       int line_termination, inter_name_termination, i;
+       const char *line_prefix = diff_line_prefix(opt);
 
        line_termination = opt->line_termination;
        inter_name_termination = '\t';
@@ -999,24 +1189,24 @@ static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct re
        if (rev->loginfo && !rev->no_commit_id)
                show_log(rev);
 
+
        if (opt->output_format & DIFF_FORMAT_RAW) {
-               offset = strlen(COLONS) - num_parent;
-               if (offset < 0)
-                       offset = 0;
-               prefix = COLONS + offset;
+               printf("%s", line_prefix);
+
+               /* As many colons as there are parents */
+               for (i = 0; i < num_parent; i++)
+                       putchar(':');
 
                /* Show the modes */
-               for (i = 0; i < num_parent; i++) {
-                       printf("%s%06o", prefix, p->parent[i].mode);
-                       prefix = " ";
-               }
-               printf("%s%06o", prefix, p->mode);
+               for (i = 0; i < num_parent; i++)
+                       printf("%06o ", p->parent[i].mode);
+               printf("%06o", p->mode);
 
                /* Show sha1's */
                for (i = 0; i < num_parent; i++)
-                       printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
-                                                        opt->abbrev));
-               printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
+                       printf(" %s", diff_aligned_abbrev(&p->parent[i].oid,
+                                                         opt->abbrev));
+               printf(" %s ", diff_aligned_abbrev(&p->oid, opt->abbrev));
        }
 
        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
@@ -1040,8 +1230,7 @@ void show_combined_diff(struct combine_diff_path *p,
                       struct rev_info *rev)
 {
        struct diff_options *opt = &rev->diffopt;
-       if (!p->len)
-               return;
+
        if (opt->output_format & (DIFF_FORMAT_RAW |
                                  DIFF_FORMAT_NAME |
                                  DIFF_FORMAT_NAME_STATUS))
@@ -1073,23 +1262,23 @@ static struct diff_filepair *combined_pair(struct combine_diff_path *p,
        struct diff_filespec *pool;
 
        pair = xmalloc(sizeof(*pair));
-       pool = xcalloc(num_parent + 1, sizeof(struct diff_filespec));
+       pool = xcalloc(st_add(num_parent, 1), sizeof(struct diff_filespec));
        pair->one = pool + 1;
        pair->two = pool;
 
        for (i = 0; i < num_parent; i++) {
                pair->one[i].path = p->path;
                pair->one[i].mode = p->parent[i].mode;
-               hashcpy(pair->one[i].sha1, p->parent[i].sha1);
-               pair->one[i].sha1_valid = !is_null_sha1(p->parent[i].sha1);
+               oidcpy(&pair->one[i].oid, &p->parent[i].oid);
+               pair->one[i].oid_valid = !is_null_oid(&p->parent[i].oid);
                pair->one[i].has_more_entries = 1;
        }
        pair->one[num_parent - 1].has_more_entries = 0;
 
        pair->two->path = p->path;
        pair->two->mode = p->mode;
-       hashcpy(pair->two->sha1, p->sha1);
-       pair->two->sha1_valid = !is_null_sha1(p->sha1);
+       oidcpy(&pair->two->oid, &p->oid);
+       pair->two->oid_valid = !is_null_oid(&p->oid);
        return pair;
 }
 
@@ -1105,70 +1294,213 @@ static void handle_combined_callback(struct diff_options *opt,
        q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
        q.alloc = num_paths;
        q.nr = num_paths;
-       for (i = 0, p = paths; p; p = p->next) {
-               if (!p->len)
-                       continue;
+       for (i = 0, p = paths; p; p = p->next)
                q.queue[i++] = combined_pair(p, num_parent);
-       }
        opt->format_callback(&q, opt, opt->format_callback_data);
        for (i = 0; i < num_paths; i++)
                free_combined_pair(q.queue[i]);
        free(q.queue);
 }
 
-void diff_tree_combined(const unsigned char *sha1,
-                       const struct sha1_array *parents,
+static const char *path_path(void *obj)
+{
+       struct combine_diff_path *path = (struct combine_diff_path *)obj;
+
+       return path->path;
+}
+
+
+/* find set of paths that every parent touches */
+static struct combine_diff_path *find_paths_generic(const struct object_id *oid,
+       const struct oid_array *parents, struct diff_options *opt)
+{
+       struct combine_diff_path *paths = NULL;
+       int i, num_parent = parents->nr;
+
+       int output_format = opt->output_format;
+       const char *orderfile = opt->orderfile;
+
+       opt->output_format = DIFF_FORMAT_NO_OUTPUT;
+       /* tell diff_tree to emit paths in sorted (=tree) order */
+       opt->orderfile = NULL;
+
+       /* D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn)  (wrt paths) */
+       for (i = 0; i < num_parent; i++) {
+               /*
+                * show stat against the first parent even when doing
+                * combined diff.
+                */
+               int stat_opt = (output_format &
+                               (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
+               if (i == 0 && stat_opt)
+                       opt->output_format = stat_opt;
+               else
+                       opt->output_format = DIFF_FORMAT_NO_OUTPUT;
+               diff_tree_oid(&parents->oid[i], oid, "", opt);
+               diffcore_std(opt);
+               paths = intersect_paths(paths, i, num_parent);
+
+               /* if showing diff, show it in requested order */
+               if (opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
+                   orderfile) {
+                       diffcore_order(orderfile);
+               }
+
+               diff_flush(opt);
+       }
+
+       opt->output_format = output_format;
+       opt->orderfile = orderfile;
+       return paths;
+}
+
+
+/*
+ * find set of paths that everybody touches, assuming diff is run without
+ * rename/copy detection, etc, comparing all trees simultaneously (= faster).
+ */
+static struct combine_diff_path *find_paths_multitree(
+       const struct object_id *oid, const struct oid_array *parents,
+       struct diff_options *opt)
+{
+       int i, nparent = parents->nr;
+       const struct object_id **parents_oid;
+       struct combine_diff_path paths_head;
+       struct strbuf base;
+
+       ALLOC_ARRAY(parents_oid, nparent);
+       for (i = 0; i < nparent; i++)
+               parents_oid[i] = &parents->oid[i];
+
+       /* fake list head, so worker can assume it is non-NULL */
+       paths_head.next = NULL;
+
+       strbuf_init(&base, PATH_MAX);
+       diff_tree_paths(&paths_head, oid, parents_oid, nparent, &base, opt);
+
+       strbuf_release(&base);
+       free(parents_oid);
+       return paths_head.next;
+}
+
+
+void diff_tree_combined(const struct object_id *oid,
+                       const struct oid_array *parents,
                        int dense,
                        struct rev_info *rev)
 {
        struct diff_options *opt = &rev->diffopt;
        struct diff_options diffopts;
-       struct combine_diff_path *p, *paths = NULL;
+       struct combine_diff_path *p, *paths;
        int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
+       int need_generic_pathscan;
+
+       /* nothing to do, if no parents */
+       if (!num_parent)
+               return;
+
+       show_log_first = !!rev->loginfo && !rev->no_commit_id;
+       needsep = 0;
+       if (show_log_first) {
+               show_log(rev);
+
+               if (rev->verbose_header && opt->output_format &&
+                   opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
+                   !commit_format_is_empty(rev->commit_format))
+                       printf("%s%c", diff_line_prefix(opt),
+                              opt->line_termination);
+       }
 
        diffopts = *opt;
-       diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
+       copy_pathspec(&diffopts.pathspec, &opt->pathspec);
        DIFF_OPT_SET(&diffopts, RECURSIVE);
        DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
 
-       show_log_first = !!rev->loginfo && !rev->no_commit_id;
-       needsep = 0;
-       /* find set of paths that everybody touches */
-       for (i = 0; i < num_parent; i++) {
-               /* show stat against the first parent even
+       /* find set of paths that everybody touches
+        *
+        * NOTE
+        *
+        * Diffcore transformations are bound to diff_filespec and logic
+        * comparing two entries - i.e. they do not apply directly to combine
+        * diff.
+        *
+        * If some of such transformations is requested - we launch generic
+        * path scanning, which works significantly slower compared to
+        * simultaneous all-trees-in-one-go scan in find_paths_multitree().
+        *
+        * TODO some of the filters could be ported to work on
+        * combine_diff_paths - i.e. all functionality that skips paths, so in
+        * theory, we could end up having only multitree path scanning.
+        *
+        * NOTE please keep this semantically in sync with diffcore_std()
+        */
+       need_generic_pathscan = opt->skip_stat_unmatch  ||
+                       DIFF_OPT_TST(opt, FOLLOW_RENAMES)       ||
+                       opt->break_opt != -1    ||
+                       opt->detect_rename      ||
+                       opt->pickaxe            ||
+                       opt->filter;
+
+
+       if (need_generic_pathscan) {
+               /*
+                * NOTE generic case also handles --stat, as it computes
+                * diff(sha1,parent_i) for all i to do the job, specifically
+                * for parent0.
+                */
+               paths = find_paths_generic(oid, parents, &diffopts);
+       }
+       else {
+               int stat_opt;
+               paths = find_paths_multitree(oid, parents, &diffopts);
+
+               /*
+                * show stat against the first parent even
                 * when doing combined diff.
                 */
-               int stat_opt = (opt->output_format &
+               stat_opt = (opt->output_format &
                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
-               if (i == 0 && stat_opt)
+               if (stat_opt) {
                        diffopts.output_format = stat_opt;
-               else
-                       diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
-               diff_tree_sha1(parents->sha1[i], sha1, "", &diffopts);
-               diffcore_std(&diffopts);
-               paths = intersect_paths(paths, i, num_parent);
 
-               if (show_log_first && i == 0) {
-                       show_log(rev);
-                       if (rev->verbose_header && opt->output_format)
-                               putchar(opt->line_termination);
+                       diff_tree_oid(&parents->oid[0], oid, "", &diffopts);
+                       diffcore_std(&diffopts);
+                       if (opt->orderfile)
+                               diffcore_order(opt->orderfile);
+                       diff_flush(&diffopts);
                }
-               diff_flush(&diffopts);
        }
 
-       /* find out surviving paths */
-       for (num_paths = 0, p = paths; p; p = p->next) {
-               if (p->len)
-                       num_paths++;
+       /* find out number of surviving paths */
+       for (num_paths = 0, p = paths; p; p = p->next)
+               num_paths++;
+
+       /* order paths according to diffcore_order */
+       if (opt->orderfile && num_paths) {
+               struct obj_order *o;
+
+               ALLOC_ARRAY(o, num_paths);
+               for (i = 0, p = paths; p; p = p->next, i++)
+                       o[i].obj = p;
+               order_objects(opt->orderfile, path_path, o, num_paths);
+               for (i = 0; i < num_paths - 1; i++) {
+                       p = o[i].obj;
+                       p->next = o[i+1].obj;
+               }
+
+               p = o[num_paths-1].obj;
+               p->next = NULL;
+               paths = o[0].obj;
+               free(o);
        }
+
+
        if (num_paths) {
                if (opt->output_format & (DIFF_FORMAT_RAW |
                                          DIFF_FORMAT_NAME |
                                          DIFF_FORMAT_NAME_STATUS)) {
-                       for (p = paths; p; p = p->next) {
-                               if (p->len)
-                                       show_raw_diff(p, num_parent, rev);
-                       }
+                       for (p = paths; p; p = p->next)
+                               show_raw_diff(p, num_parent, rev);
                        needsep = 1;
                }
                else if (opt->output_format &
@@ -1179,12 +1511,11 @@ void diff_tree_combined(const unsigned char *sha1,
 
                if (opt->output_format & DIFF_FORMAT_PATCH) {
                        if (needsep)
-                               putchar(opt->line_termination);
-                       for (p = paths; p; p = p->next) {
-                               if (p->len)
-                                       show_patch_diff(p, num_parent, dense,
-                                                       0, rev);
-                       }
+                               printf("%s%c", diff_line_prefix(opt),
+                                      opt->line_termination);
+                       for (p = paths; p; p = p->next)
+                               show_patch_diff(p, num_parent, dense,
+                                               0, rev);
                }
        }
 
@@ -1194,18 +1525,20 @@ void diff_tree_combined(const unsigned char *sha1,
                paths = paths->next;
                free(tmp);
        }
+
+       clear_pathspec(&diffopts.pathspec);
 }
 
 void diff_tree_combined_merge(const struct commit *commit, int dense,
                              struct rev_info *rev)
 {
-       struct commit_list *parent = commit->parents;
-       struct sha1_array parents = SHA1_ARRAY_INIT;
+       struct commit_list *parent = get_saved_parents(rev, commit);
+       struct oid_array parents = OID_ARRAY_INIT;
 
        while (parent) {
-               sha1_array_append(&parents, parent->item->object.sha1);
+               oid_array_append(&parents, &parent->item->object.oid);
                parent = parent->next;
        }
-       diff_tree_combined(commit->object.sha1, &parents, dense, rev);
-       sha1_array_clear(&parents);
+       diff_tree_combined(&commit->object.oid, &parents, dense, rev);
+       oid_array_clear(&parents);
 }