Imported Upstream version 2.12.4
[platform/upstream/git.git] / refs.c
diff --git a/refs.c b/refs.c
index b0e6ece..2d71774 100644 (file)
--- a/refs.c
+++ b/refs.c
 #include "tag.h"
 
 /*
+ * List of all available backends
+ */
+static struct ref_storage_be *refs_backends = &refs_be_files;
+
+static struct ref_storage_be *find_ref_storage_backend(const char *name)
+{
+       struct ref_storage_be *be;
+       for (be = refs_backends; be; be = be->next)
+               if (!strcmp(be->name, name))
+                       return be;
+       return NULL;
+}
+
+int ref_storage_backend_exists(const char *name)
+{
+       return find_ref_storage_backend(name) != NULL;
+}
+
+/*
  * How to handle various characters in refnames:
  * 0: An acceptable character for refs
  * 1: End-of-component
@@ -120,25 +139,33 @@ int check_refname_format(const char *refname, int flags)
 
 int refname_is_safe(const char *refname)
 {
-       if (starts_with(refname, "refs/")) {
+       const char *rest;
+
+       if (skip_prefix(refname, "refs/", &rest)) {
                char *buf;
                int result;
+               size_t restlen = strlen(rest);
+
+               /* rest must not be empty, or start or end with "/" */
+               if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
+                       return 0;
 
-               buf = xmallocz(strlen(refname));
                /*
                 * Does the refname try to escape refs/?
                 * For example: refs/foo/../bar is safe but refs/foo/../../bar
                 * is not.
                 */
-               result = !normalize_path_copy(buf, refname + strlen("refs/"));
+               buf = xmallocz(restlen);
+               result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
                free(buf);
                return result;
        }
-       while (*refname) {
+
+       do {
                if (!isupper(*refname) && *refname != '_')
                        return 0;
                refname++;
-       }
+       } while (*refname);
        return 1;
 }
 
@@ -377,7 +404,7 @@ int refname_match(const char *abbrev_name, const char *full_name)
 static char *substitute_branch_name(const char **string, int *len)
 {
        struct strbuf buf = STRBUF_INIT;
-       int ret = interpret_branch_name(*string, *len, &buf);
+       int ret = interpret_branch_name(*string, *len, &buf, 0);
 
        if (ret == *len) {
                size_t size;
@@ -392,6 +419,13 @@ static char *substitute_branch_name(const char **string, int *len)
 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
 {
        char *last_branch = substitute_branch_name(&str, &len);
+       int   refs_found  = expand_ref(str, len, sha1, ref);
+       free(last_branch);
+       return refs_found;
+}
+
+int expand_ref(const char *str, int len, unsigned char *sha1, char **ref)
+{
        const char **p, *r;
        int refs_found = 0;
 
@@ -417,7 +451,6 @@ int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
                        warning("ignoring broken ref %s.", fullref);
                }
        }
-       free(last_branch);
        return refs_found;
 }
 
@@ -496,7 +529,7 @@ static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
        filename = git_path("%s", pseudoref);
        fd = hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR);
        if (fd < 0) {
-               strbuf_addf(err, "Could not open '%s' for writing: %s",
+               strbuf_addf(err, "could not open '%s' for writing: %s",
                            filename, strerror(errno));
                return -1;
        }
@@ -507,14 +540,14 @@ static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
                if (read_ref(pseudoref, actual_old_sha1))
                        die("could not read ref '%s'", pseudoref);
                if (hashcmp(actual_old_sha1, old_sha1)) {
-                       strbuf_addf(err, "Unexpected sha1 when writing %s", pseudoref);
+                       strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
                        rollback_lock_file(&lock);
                        goto done;
                }
        }
 
        if (write_in_full(fd, buf.buf, buf.len) != buf.len) {
-               strbuf_addf(err, "Could not write to '%s'", filename);
+               strbuf_addf(err, "could not write to '%s'", filename);
                rollback_lock_file(&lock);
                goto done;
        }
@@ -605,12 +638,17 @@ int copy_reflog_msg(char *buf, const char *msg)
 
 int should_autocreate_reflog(const char *refname)
 {
-       if (!log_all_ref_updates)
+       switch (log_all_ref_updates) {
+       case LOG_REFS_ALWAYS:
+               return 1;
+       case LOG_REFS_NORMAL:
+               return starts_with(refname, "refs/heads/") ||
+                       starts_with(refname, "refs/remotes/") ||
+                       starts_with(refname, "refs/notes/") ||
+                       !strcmp(refname, "HEAD");
+       default:
                return 0;
-       return starts_with(refname, "refs/heads/") ||
-               starts_with(refname, "refs/remotes/") ||
-               starts_with(refname, "refs/notes/") ||
-               !strcmp(refname, "HEAD");
+       }
 }
 
 int is_branch(const char *refname)
@@ -758,13 +796,32 @@ void ref_transaction_free(struct ref_transaction *transaction)
        free(transaction);
 }
 
-static struct ref_update *add_update(struct ref_transaction *transaction,
-                                    const char *refname)
+struct ref_update *ref_transaction_add_update(
+               struct ref_transaction *transaction,
+               const char *refname, unsigned int flags,
+               const unsigned char *new_sha1,
+               const unsigned char *old_sha1,
+               const char *msg)
 {
        struct ref_update *update;
+
+       if (transaction->state != REF_TRANSACTION_OPEN)
+               die("BUG: update called for transaction that is not open");
+
+       if ((flags & REF_ISPRUNING) && !(flags & REF_NODEREF))
+               die("BUG: REF_ISPRUNING set without REF_NODEREF");
+
        FLEX_ALLOC_STR(update, refname, refname);
        ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
        transaction->updates[transaction->nr++] = update;
+
+       update->flags = flags;
+
+       if (flags & REF_HAVE_NEW)
+               hashcpy(update->new_sha1, new_sha1);
+       if (flags & REF_HAVE_OLD)
+               hashcpy(update->old_sha1, old_sha1);
+       update->msg = xstrdup_or_null(msg);
        return update;
 }
 
@@ -775,32 +832,20 @@ int ref_transaction_update(struct ref_transaction *transaction,
                           unsigned int flags, const char *msg,
                           struct strbuf *err)
 {
-       struct ref_update *update;
-
        assert(err);
 
-       if (transaction->state != REF_TRANSACTION_OPEN)
-               die("BUG: update called for transaction that is not open");
-
-       if (new_sha1 && !is_null_sha1(new_sha1) &&
-           check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
-               strbuf_addf(err, "refusing to update ref with bad name %s",
+       if ((new_sha1 && !is_null_sha1(new_sha1)) ?
+           check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
+           !refname_is_safe(refname)) {
+               strbuf_addf(err, "refusing to update ref with bad name '%s'",
                            refname);
                return -1;
        }
 
-       update = add_update(transaction, refname);
-       if (new_sha1) {
-               hashcpy(update->new_sha1, new_sha1);
-               flags |= REF_HAVE_NEW;
-       }
-       if (old_sha1) {
-               hashcpy(update->old_sha1, old_sha1);
-               flags |= REF_HAVE_OLD;
-       }
-       update->flags = flags;
-       if (msg)
-               update->msg = xstrdup(msg);
+       flags |= (new_sha1 ? REF_HAVE_NEW : 0) | (old_sha1 ? REF_HAVE_OLD : 0);
+
+       ref_transaction_add_update(transaction, refname, flags,
+                                  new_sha1, old_sha1, msg);
        return 0;
 }
 
@@ -842,6 +887,14 @@ int ref_transaction_verify(struct ref_transaction *transaction,
                                      flags, NULL, err);
 }
 
+int update_ref_oid(const char *msg, const char *refname,
+              const struct object_id *new_oid, const struct object_id *old_oid,
+              unsigned int flags, enum action_on_err onerr)
+{
+       return update_ref(msg, refname, new_oid ? new_oid->hash : NULL,
+               old_oid ? old_oid->hash : NULL, flags, onerr);
+}
+
 int update_ref(const char *msg, const char *refname,
               const unsigned char *new_sha1, const unsigned char *old_sha1,
               unsigned int flags, enum action_on_err onerr)
@@ -906,7 +959,7 @@ char *shorten_unambiguous_ref(const char *refname, int strict)
                        /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
                        total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
 
-               scanf_fmts = xmalloc(st_add(st_mult(nr_rules, sizeof(char *)), total_len));
+               scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
 
                offset = 0;
                for (i = 0; i < nr_rules; i++) {
@@ -981,10 +1034,10 @@ static struct string_list *hide_refs;
 
 int parse_hide_refs_config(const char *var, const char *value, const char *section)
 {
+       const char *key;
        if (!strcmp("transfer.hiderefs", var) ||
-           /* NEEDSWORK: use parse_config_key() once both are merged */
-           (starts_with(var, section) && var[strlen(section)] == '.' &&
-            !strcmp(var + strlen(section), ".hiderefs"))) {
+           (!parse_config_key(var, section, NULL, NULL, &key) &&
+            !strcmp(key, "hiderefs"))) {
                char *ref;
                int len;
 
@@ -1065,18 +1118,457 @@ const char *find_descendant_ref(const char *dirname,
        return NULL;
 }
 
-int rename_ref_available(const char *oldname, const char *newname)
+int rename_ref_available(const char *old_refname, const char *new_refname)
 {
        struct string_list skip = STRING_LIST_INIT_NODUP;
        struct strbuf err = STRBUF_INIT;
-       int ret;
+       int ok;
 
-       string_list_insert(&skip, oldname);
-       ret = !verify_refname_available(newname, NULL, &skip, &err);
-       if (!ret)
+       string_list_insert(&skip, old_refname);
+       ok = !verify_refname_available(new_refname, NULL, &skip, &err);
+       if (!ok)
                error("%s", err.buf);
 
        string_list_clear(&skip, 0);
        strbuf_release(&err);
+       return ok;
+}
+
+int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
+{
+       struct object_id oid;
+       int flag;
+
+       if (submodule) {
+               if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0)
+                       return fn("HEAD", &oid, 0, cb_data);
+
+               return 0;
+       }
+
+       if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag))
+               return fn("HEAD", &oid, flag, cb_data);
+
+       return 0;
+}
+
+int head_ref(each_ref_fn fn, void *cb_data)
+{
+       return head_ref_submodule(NULL, fn, cb_data);
+}
+
+/*
+ * Call fn for each reference in the specified submodule for which the
+ * refname begins with prefix. If trim is non-zero, then trim that
+ * many characters off the beginning of each refname before passing
+ * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
+ * include broken references in the iteration. If fn ever returns a
+ * non-zero value, stop the iteration and return that value;
+ * otherwise, return 0.
+ */
+static int do_for_each_ref(const char *submodule, const char *prefix,
+                          each_ref_fn fn, int trim, int flags, void *cb_data)
+{
+       struct ref_store *refs = get_ref_store(submodule);
+       struct ref_iterator *iter;
+
+       if (!refs)
+               return 0;
+
+       iter = refs->be->iterator_begin(refs, prefix, flags);
+       iter = prefix_ref_iterator_begin(iter, prefix, trim);
+
+       return do_for_each_ref_iterator(iter, fn, cb_data);
+}
+
+int for_each_ref(each_ref_fn fn, void *cb_data)
+{
+       return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
+}
+
+int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
+{
+       return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
+}
+
+int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
+{
+       return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
+}
+
+int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
+{
+       unsigned int flag = 0;
+
+       if (broken)
+               flag = DO_FOR_EACH_INCLUDE_BROKEN;
+       return do_for_each_ref(NULL, prefix, fn, 0, flag, cb_data);
+}
+
+int for_each_ref_in_submodule(const char *submodule, const char *prefix,
+               each_ref_fn fn, void *cb_data)
+{
+       return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
+}
+
+int for_each_replace_ref(each_ref_fn fn, void *cb_data)
+{
+       return do_for_each_ref(NULL, git_replace_ref_base, fn,
+                              strlen(git_replace_ref_base), 0, cb_data);
+}
+
+int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
+{
+       struct strbuf buf = STRBUF_INIT;
+       int ret;
+       strbuf_addf(&buf, "%srefs/", get_git_namespace());
+       ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
+       strbuf_release(&buf);
        return ret;
 }
+
+int for_each_rawref(each_ref_fn fn, void *cb_data)
+{
+       return do_for_each_ref(NULL, "", fn, 0,
+                              DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
+}
+
+/* This function needs to return a meaningful errno on failure */
+static const char *resolve_ref_recursively(struct ref_store *refs,
+                                          const char *refname,
+                                          int resolve_flags,
+                                          unsigned char *sha1, int *flags)
+{
+       static struct strbuf sb_refname = STRBUF_INIT;
+       int unused_flags;
+       int symref_count;
+
+       if (!flags)
+               flags = &unused_flags;
+
+       *flags = 0;
+
+       if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+               if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
+                   !refname_is_safe(refname)) {
+                       errno = EINVAL;
+                       return NULL;
+               }
+
+               /*
+                * dwim_ref() uses REF_ISBROKEN to distinguish between
+                * missing refs and refs that were present but invalid,
+                * to complain about the latter to stderr.
+                *
+                * We don't know whether the ref exists, so don't set
+                * REF_ISBROKEN yet.
+                */
+               *flags |= REF_BAD_NAME;
+       }
+
+       for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
+               unsigned int read_flags = 0;
+
+               if (refs->be->read_raw_ref(refs, refname,
+                                          sha1, &sb_refname, &read_flags)) {
+                       *flags |= read_flags;
+                       if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
+                               return NULL;
+                       hashclr(sha1);
+                       if (*flags & REF_BAD_NAME)
+                               *flags |= REF_ISBROKEN;
+                       return refname;
+               }
+
+               *flags |= read_flags;
+
+               if (!(read_flags & REF_ISSYMREF)) {
+                       if (*flags & REF_BAD_NAME) {
+                               hashclr(sha1);
+                               *flags |= REF_ISBROKEN;
+                       }
+                       return refname;
+               }
+
+               refname = sb_refname.buf;
+               if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
+                       hashclr(sha1);
+                       return refname;
+               }
+               if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+                       if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
+                           !refname_is_safe(refname)) {
+                               errno = EINVAL;
+                               return NULL;
+                       }
+
+                       *flags |= REF_ISBROKEN | REF_BAD_NAME;
+               }
+       }
+
+       errno = ELOOP;
+       return NULL;
+}
+
+/* backend functions */
+int refs_init_db(struct strbuf *err)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->init_db(refs, err);
+}
+
+const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
+                              unsigned char *sha1, int *flags)
+{
+       return resolve_ref_recursively(get_ref_store(NULL), refname,
+                                      resolve_flags, sha1, flags);
+}
+
+int resolve_gitlink_ref(const char *submodule, const char *refname,
+                       unsigned char *sha1)
+{
+       size_t len = strlen(submodule);
+       struct ref_store *refs;
+       int flags;
+
+       while (len && submodule[len - 1] == '/')
+               len--;
+
+       if (!len)
+               return -1;
+
+       if (submodule[len]) {
+               /* We need to strip off one or more trailing slashes */
+               char *stripped = xmemdupz(submodule, len);
+
+               refs = get_ref_store(stripped);
+               free(stripped);
+       } else {
+               refs = get_ref_store(submodule);
+       }
+
+       if (!refs)
+               return -1;
+
+       if (!resolve_ref_recursively(refs, refname, 0, sha1, &flags) ||
+           is_null_sha1(sha1))
+               return -1;
+       return 0;
+}
+
+/* A pointer to the ref_store for the main repository: */
+static struct ref_store *main_ref_store;
+
+/* A linked list of ref_stores for submodules: */
+static struct ref_store *submodule_ref_stores;
+
+void base_ref_store_init(struct ref_store *refs,
+                        const struct ref_storage_be *be,
+                        const char *submodule)
+{
+       refs->be = be;
+       if (!submodule) {
+               if (main_ref_store)
+                       die("BUG: main_ref_store initialized twice");
+
+               refs->submodule = "";
+               refs->next = NULL;
+               main_ref_store = refs;
+       } else {
+               if (lookup_ref_store(submodule))
+                       die("BUG: ref_store for submodule '%s' initialized twice",
+                           submodule);
+
+               refs->submodule = xstrdup(submodule);
+               refs->next = submodule_ref_stores;
+               submodule_ref_stores = refs;
+       }
+}
+
+struct ref_store *ref_store_init(const char *submodule)
+{
+       const char *be_name = "files";
+       struct ref_storage_be *be = find_ref_storage_backend(be_name);
+
+       if (!be)
+               die("BUG: reference backend %s is unknown", be_name);
+
+       if (!submodule || !*submodule)
+               return be->init(NULL);
+       else
+               return be->init(submodule);
+}
+
+struct ref_store *lookup_ref_store(const char *submodule)
+{
+       struct ref_store *refs;
+
+       if (!submodule || !*submodule)
+               return main_ref_store;
+
+       for (refs = submodule_ref_stores; refs; refs = refs->next) {
+               if (!strcmp(submodule, refs->submodule))
+                       return refs;
+       }
+
+       return NULL;
+}
+
+struct ref_store *get_ref_store(const char *submodule)
+{
+       struct ref_store *refs;
+
+       if (!submodule || !*submodule) {
+               refs = lookup_ref_store(NULL);
+
+               if (!refs)
+                       refs = ref_store_init(NULL);
+       } else {
+               refs = lookup_ref_store(submodule);
+
+               if (!refs) {
+                       struct strbuf submodule_sb = STRBUF_INIT;
+
+                       strbuf_addstr(&submodule_sb, submodule);
+                       if (is_nonbare_repository_dir(&submodule_sb))
+                               refs = ref_store_init(submodule);
+                       strbuf_release(&submodule_sb);
+               }
+       }
+
+       return refs;
+}
+
+void assert_main_repository(struct ref_store *refs, const char *caller)
+{
+       if (*refs->submodule)
+               die("BUG: %s called for a submodule", caller);
+}
+
+/* backend functions */
+int pack_refs(unsigned int flags)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->pack_refs(refs, flags);
+}
+
+int peel_ref(const char *refname, unsigned char *sha1)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->peel_ref(refs, refname, sha1);
+}
+
+int create_symref(const char *ref_target, const char *refs_heads_master,
+                 const char *logmsg)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->create_symref(refs, ref_target, refs_heads_master,
+                                      logmsg);
+}
+
+int ref_transaction_commit(struct ref_transaction *transaction,
+                          struct strbuf *err)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->transaction_commit(refs, transaction, err);
+}
+
+int verify_refname_available(const char *refname,
+                            const struct string_list *extra,
+                            const struct string_list *skip,
+                            struct strbuf *err)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->verify_refname_available(refs, refname, extra, skip, err);
+}
+
+int for_each_reflog(each_ref_fn fn, void *cb_data)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+       struct ref_iterator *iter;
+
+       iter = refs->be->reflog_iterator_begin(refs);
+
+       return do_for_each_ref_iterator(iter, fn, cb_data);
+}
+
+int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
+                               void *cb_data)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->for_each_reflog_ent_reverse(refs, refname,
+                                                    fn, cb_data);
+}
+
+int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
+                       void *cb_data)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
+}
+
+int reflog_exists(const char *refname)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->reflog_exists(refs, refname);
+}
+
+int safe_create_reflog(const char *refname, int force_create,
+                      struct strbuf *err)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->create_reflog(refs, refname, force_create, err);
+}
+
+int delete_reflog(const char *refname)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->delete_reflog(refs, refname);
+}
+
+int reflog_expire(const char *refname, const unsigned char *sha1,
+                 unsigned int flags,
+                 reflog_expiry_prepare_fn prepare_fn,
+                 reflog_expiry_should_prune_fn should_prune_fn,
+                 reflog_expiry_cleanup_fn cleanup_fn,
+                 void *policy_cb_data)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->reflog_expire(refs, refname, sha1, flags,
+                                      prepare_fn, should_prune_fn,
+                                      cleanup_fn, policy_cb_data);
+}
+
+int initial_ref_transaction_commit(struct ref_transaction *transaction,
+                                  struct strbuf *err)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->initial_transaction_commit(refs, transaction, err);
+}
+
+int delete_refs(struct string_list *refnames, unsigned int flags)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->delete_refs(refs, refnames, flags);
+}
+
+int rename_ref(const char *oldref, const char *newref, const char *logmsg)
+{
+       struct ref_store *refs = get_ref_store(NULL);
+
+       return refs->be->rename_ref(refs, oldref, newref, logmsg);
+}