Merge branch 'jk/misc-resolve-ref-unsafe-fixes'
[gitweb.git] / refs.c
diff --git a/refs.c b/refs.c
index 41aec6505d1309fa2efed2bd9aca0a0ef2646444..c590a992fb19ce92dcf0932b58f83b65028f8316 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -174,6 +174,24 @@ int refname_is_safe(const char *refname)
        return 1;
 }
 
+/*
+ * Return true if refname, which has the specified oid and flags, can
+ * be resolved to an object in the database. If the referred-to object
+ * does not exist, emit a warning and return false.
+ */
+int ref_resolves_to_object(const char *refname,
+                          const struct object_id *oid,
+                          unsigned int flags)
+{
+       if (flags & REF_ISBROKEN)
+               return 0;
+       if (!has_sha1_file(oid->hash)) {
+               error("%s does not point to a valid object!", refname);
+               return 0;
+       }
+       return 1;
+}
+
 char *refs_resolve_refdup(struct ref_store *refs,
                          const char *refname, int resolve_flags,
                          unsigned char *sha1, int *flags)
@@ -221,8 +239,7 @@ int read_ref(const char *refname, unsigned char *sha1)
 
 int ref_exists(const char *refname)
 {
-       unsigned char sha1[20];
-       return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
+       return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
 }
 
 static int filter_refs(const char *refname, const struct object_id *oid,
@@ -268,12 +285,11 @@ static int warn_if_dangling_symref(const char *refname, const struct object_id *
 {
        struct warn_if_dangling_data *d = cb_data;
        const char *resolves_to;
-       struct object_id junk;
 
        if (!(flags & REF_ISSYMREF))
                return 0;
 
-       resolves_to = resolve_ref_unsafe(refname, 0, junk.hash, NULL);
+       resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
        if (!resolves_to
            || (d->refname
                ? strcmp(resolves_to, d->refname)
@@ -318,12 +334,6 @@ int for_each_tag_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_tag_ref(get_submodule_ref_store(submodule),
-                                    fn, cb_data);
-}
-
 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
        return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
@@ -334,12 +344,6 @@ int for_each_branch_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_branch_ref(get_submodule_ref_store(submodule),
-                                       fn, cb_data);
-}
-
 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 {
        return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
@@ -350,12 +354,6 @@ int for_each_remote_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
-                                       fn, cb_data);
-}
-
 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
 {
        struct strbuf buf = STRBUF_INIT;
@@ -561,6 +559,21 @@ enum ref_type ref_type(const char *refname)
        return REF_TYPE_NORMAL;
 }
 
+long get_files_ref_lock_timeout_ms(void)
+{
+       static int configured = 0;
+
+       /* The default timeout is 100 ms: */
+       static int timeout_ms = 100;
+
+       if (!configured) {
+               git_config_get_int("core.filesreflocktimeout", &timeout_ms);
+               configured = 1;
+       }
+
+       return timeout_ms;
+}
+
 static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
                           const unsigned char *old_sha1, struct strbuf *err)
 {
@@ -573,11 +586,13 @@ static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
        strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
 
        filename = git_path("%s", pseudoref);
-       fd = hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR);
+       fd = hold_lock_file_for_update_timeout(&lock, filename,
+                                              LOCK_DIE_ON_ERROR,
+                                              get_files_ref_lock_timeout_ms());
        if (fd < 0) {
                strbuf_addf(err, "could not open '%s' for writing: %s",
                            filename, strerror(errno));
-               return -1;
+               goto done;
        }
 
        if (old_sha1) {
@@ -592,7 +607,7 @@ static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
                }
        }
 
-       if (write_in_full(fd, buf.buf, buf.len) != buf.len) {
+       if (write_in_full(fd, buf.buf, buf.len) < 0) {
                strbuf_addf(err, "could not write to '%s'", filename);
                rollback_lock_file(&lock);
                goto done;
@@ -616,8 +631,9 @@ static int delete_pseudoref(const char *pseudoref, const unsigned char *old_sha1
                int fd;
                unsigned char actual_old_sha1[20];
 
-               fd = hold_lock_file_for_update(&lock, filename,
-                                              LOCK_DIE_ON_ERROR);
+               fd = hold_lock_file_for_update_timeout(
+                               &lock, filename, LOCK_DIE_ON_ERROR,
+                               get_files_ref_lock_timeout_ms());
                if (fd < 0)
                        die_errno(_("Could not open '%s' for writing"), filename);
                if (read_ref(pseudoref, actual_old_sha1))
@@ -818,7 +834,7 @@ int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, in
        for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 
        if (!cb.reccnt) {
-               if (flags & GET_SHA1_QUIETLY)
+               if (flags & GET_OID_QUIETLY)
                        exit(128);
                else
                        die("Log for %s is empty.", refname);
@@ -1232,19 +1248,13 @@ int refs_rename_ref_available(struct ref_store *refs,
        return ok;
 }
 
-int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
+int refs_head_ref(struct ref_store *refs, 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))
+       if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
+                               oid.hash, &flag))
                return fn("HEAD", &oid, flag, cb_data);
 
        return 0;
@@ -1252,7 +1262,7 @@ int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
 
 int head_ref(each_ref_fn fn, void *cb_data)
 {
-       return head_ref_submodule(NULL, fn, cb_data);
+       return refs_head_ref(get_main_ref_store(), fn, cb_data);
 }
 
 struct ref_iterator *refs_ref_iterator_begin(
@@ -1275,6 +1285,10 @@ struct ref_iterator *refs_ref_iterator_begin(
        if (trim)
                iter = prefix_ref_iterator_begin(iter, "", trim);
 
+       /* Sanity check for subclasses: */
+       if (!iter->ordered)
+               BUG("reference iterator is not ordered");
+
        return iter;
 }
 
@@ -1310,11 +1324,6 @@ int for_each_ref(each_ref_fn fn, void *cb_data)
        return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
 }
 
-int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
-{
-       return refs_for_each_ref(get_submodule_ref_store(submodule), fn, cb_data);
-}
-
 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
                         each_ref_fn fn, void *cb_data)
 {
@@ -1336,23 +1345,15 @@ int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsig
                               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 refs_for_each_ref_in(get_submodule_ref_store(submodule),
-                                   prefix, fn, cb_data);
-}
-
-int for_each_fullref_in_submodule(const char *submodule, const char *prefix,
-                                 each_ref_fn fn, void *cb_data,
-                                 unsigned int broken)
+int refs_for_each_fullref_in(struct ref_store *refs, 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(get_submodule_ref_store(submodule),
-                              prefix, fn, 0, flag, cb_data);
+       return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
 }
 
 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
@@ -1360,7 +1361,7 @@ int for_each_replace_ref(each_ref_fn fn, void *cb_data)
        return do_for_each_ref(get_main_ref_store(),
                               git_replace_ref_base, fn,
                               strlen(git_replace_ref_base),
-                              0, cb_data);
+                              DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
 }
 
 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
@@ -1399,9 +1400,12 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
                                    unsigned char *sha1, int *flags)
 {
        static struct strbuf sb_refname = STRBUF_INIT;
+       struct object_id unused_oid;
        int unused_flags;
        int symref_count;
 
+       if (!sha1)
+               sha1 = unused_oid.hash;
        if (!flags)
                flags = &unused_flags;
 
@@ -1431,8 +1435,21 @@ const char *refs_resolve_ref_unsafe(struct ref_store *refs,
                if (refs_read_raw_ref(refs, refname,
                                      sha1, &sb_refname, &read_flags)) {
                        *flags |= read_flags;
-                       if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
+
+                       /* In reading mode, refs must eventually resolve */
+                       if (resolve_flags & RESOLVE_REF_READING)
+                               return NULL;
+
+                       /*
+                        * Otherwise a missing ref is OK. But the files backend
+                        * may show errors besides ENOENT if there are
+                        * similarly-named refs.
+                        */
+                       if (errno != ENOENT &&
+                           errno != EISDIR &&
+                           errno != ENOTDIR)
                                return NULL;
+
                        hashclr(sha1);
                        if (*flags & REF_BAD_NAME)
                                *flags |= REF_ISBROKEN;
@@ -1487,25 +1504,10 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_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_submodule_ref_store(stripped);
-               free(stripped);
-       } else {
-               refs = get_submodule_ref_store(submodule);
-       }
+       refs = get_submodule_ref_store(submodule);
 
        if (!refs)
                return -1;
@@ -1620,31 +1622,32 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
 {
        struct strbuf submodule_sb = STRBUF_INIT;
        struct ref_store *refs;
-       int ret;
+       char *to_free = NULL;
+       size_t len;
 
-       if (!submodule || !*submodule) {
-               /*
-                * FIXME: This case is ideally not allowed. But that
-                * can't happen until we clean up all the callers.
-                */
-               return get_main_ref_store();
-       }
+       if (!submodule)
+               return NULL;
+
+       len = strlen(submodule);
+       while (len && is_dir_sep(submodule[len - 1]))
+               len--;
+       if (!len)
+               return NULL;
+
+       if (submodule[len])
+               /* We need to strip off one or more trailing slashes */
+               submodule = to_free = xmemdupz(submodule, len);
 
        refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
        if (refs)
-               return refs;
+               goto done;
 
        strbuf_addstr(&submodule_sb, submodule);
-       ret = is_nonbare_repository_dir(&submodule_sb);
-       strbuf_release(&submodule_sb);
-       if (!ret)
-               return NULL;
+       if (!is_nonbare_repository_dir(&submodule_sb))
+               goto done;
 
-       ret = submodule_to_gitdir(&submodule_sb, submodule);
-       if (ret) {
-               strbuf_release(&submodule_sb);
-               return NULL;
-       }
+       if (submodule_to_gitdir(&submodule_sb, submodule))
+               goto done;
 
        /* assume that add_submodule_odb() has been called */
        refs = ref_store_init(submodule_sb.buf,
@@ -1652,7 +1655,10 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
        register_ref_store_map(&submodule_ref_stores, "submodule",
                               refs, submodule);
 
+done:
        strbuf_release(&submodule_sb);
+       free(to_free);
+
        return refs;
 }
 
@@ -1697,7 +1703,23 @@ int refs_pack_refs(struct ref_store *refs, unsigned int flags)
 int refs_peel_ref(struct ref_store *refs, const char *refname,
                  unsigned char *sha1)
 {
-       return refs->be->peel_ref(refs, refname, sha1);
+       int flag;
+       unsigned char base[20];
+
+       if (current_ref_iter && current_ref_iter->refname == refname) {
+               struct object_id peeled;
+
+               if (ref_iterator_peel(current_ref_iter, &peeled))
+                       return -1;
+               hashcpy(sha1, peeled.hash);
+               return 0;
+       }
+
+       if (refs_read_ref_full(refs, refname,
+                              RESOLVE_REF_READING, base, &flag))
+               return -1;
+
+       return peel_object(base, sha1);
 }
 
 int peel_ref(const char *refname, unsigned char *sha1)
@@ -2047,3 +2069,14 @@ int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 {
        return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
 }
+
+int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
+                   const char *newref, const char *logmsg)
+{
+       return refs->be->copy_ref(refs, oldref, newref, logmsg);
+}
+
+int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
+{
+       return refs_copy_existing_ref(get_main_ref_store(), oldref, newref, logmsg);
+}