]> git.ipfire.org Git - thirdparty/git.git/blobdiff - refs.c
refname_is_safe(): improve docstring
[thirdparty/git.git] / refs.c
diff --git a/refs.c b/refs.c
index 4e15f60d98ea8affdef226bce199935fa694b195..f48c58a7b672920d3975c21a2bcd61f6b55ab8ec 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -304,6 +304,11 @@ struct ref_entry {
 };
 
 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
+static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len);
+static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
+                                         const char *dirname, size_t len,
+                                         int incomplete);
+static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry);
 
 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
 {
@@ -312,19 +317,41 @@ static struct ref_dir *get_ref_dir(struct ref_entry *entry)
        dir = &entry->u.subdir;
        if (entry->flag & REF_INCOMPLETE) {
                read_loose_refs(entry->name, dir);
+
+               /*
+                * Manually add refs/bisect, which, being
+                * per-worktree, might not appear in the directory
+                * listing for refs/ in the main repo.
+                */
+               if (!strcmp(entry->name, "refs/")) {
+                       int pos = search_ref_dir(dir, "refs/bisect/", 12);
+                       if (pos < 0) {
+                               struct ref_entry *child_entry;
+                               child_entry = create_dir_entry(dir->ref_cache,
+                                                              "refs/bisect/",
+                                                              12, 1);
+                               add_entry_to_dir(dir, child_entry);
+                               read_loose_refs("refs/bisect",
+                                               &child_entry->u.subdir);
+                       }
+               }
                entry->flag &= ~REF_INCOMPLETE;
        }
        return dir;
 }
 
 /*
- * Check if a refname is safe.
- * For refs that start with "refs/" we consider it safe as long they do
- * not try to resolve to outside of refs/.
+ * Return true iff refname is minimally safe. "Safe" here means that
+ * deleting a loose reference by this name will not do any damage, for
+ * example by causing a file that is not a reference to be deleted.
+ * This function does not check that the reference name is legal; for
+ * that, use check_refname_format().
  *
- * For all other refs we only consider them safe iff they only contain
- * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like
- * "config").
+ * We consider a refname that starts with "refs/" to be safe as long
+ * as any ".." components that it might contain do not escape "refs/".
+ * Names that do not start with "refs/" are considered safe iff they
+ * consist entirely of upper case characters and '_' (like "HEAD" and
+ * "MERGE_HEAD" but not "config" or "FOO/BAR").
  */
 static int refname_is_safe(const char *refname)
 {
@@ -874,25 +901,13 @@ static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
 /*
  * Return 0 if a reference named refname could be created without
  * conflicting with the name of an existing reference in dir.
- * Otherwise, return a negative value and write an explanation to err.
- * If extras is non-NULL, it is a list of additional refnames with
- * which refname is not allowed to conflict. If skip is non-NULL,
- * ignore potential conflicts with refs in skip (e.g., because they
- * are scheduled for deletion in the same operation). Behavior is
- * undefined if the same name is listed in both extras and skip.
- *
- * Two reference names conflict if one of them exactly matches the
- * leading components of the other; e.g., "refs/foo/bar" conflicts
- * with both "refs/foo" and with "refs/foo/bar/baz" but not with
- * "refs/foo/bar" or "refs/foo/barbados".
- *
- * extras and skip must be sorted.
+ * See verify_refname_available for more information.
  */
-static int verify_refname_available(const char *refname,
-                                   const struct string_list *extras,
-                                   const struct string_list *skip,
-                                   struct ref_dir *dir,
-                                   struct strbuf *err)
+static int verify_refname_available_dir(const char *refname,
+                                       const struct string_list *extras,
+                                       const struct string_list *skip,
+                                       struct ref_dir *dir,
+                                       struct strbuf *err)
 {
        const char *slash;
        int pos;
@@ -1579,16 +1594,15 @@ static int resolve_missing_loose_ref(const char *refname,
 }
 
 /* This function needs to return a meaningful errno on failure */
-static const char *resolve_ref_unsafe_1(const char *refname,
-                                       int resolve_flags,
-                                       unsigned char *sha1,
-                                       int *flags,
-                                       struct strbuf *sb_path)
+static const char *resolve_ref_1(const char *refname,
+                                int resolve_flags,
+                                unsigned char *sha1,
+                                int *flags,
+                                struct strbuf *sb_refname,
+                                struct strbuf *sb_path,
+                                struct strbuf *sb_contents)
 {
        int depth = MAXDEPTH;
-       ssize_t len;
-       char buffer[256];
-       static char refname_buffer[256];
        int bad_name = 0;
 
        if (flags)
@@ -1654,19 +1668,18 @@ static const char *resolve_ref_unsafe_1(const char *refname,
 
                /* Follow "normalized" - ie "refs/.." symlinks by hand */
                if (S_ISLNK(st.st_mode)) {
-                       len = readlink(path, buffer, sizeof(buffer)-1);
-                       if (len < 0) {
+                       strbuf_reset(sb_contents);
+                       if (strbuf_readlink(sb_contents, path, 0) < 0) {
                                if (errno == ENOENT || errno == EINVAL)
                                        /* inconsistent with lstat; retry */
                                        goto stat_ref;
                                else
                                        return NULL;
                        }
-                       buffer[len] = 0;
-                       if (starts_with(buffer, "refs/") &&
-                                       !check_refname_format(buffer, 0)) {
-                               strcpy(refname_buffer, buffer);
-                               refname = refname_buffer;
+                       if (starts_with(sb_contents->buf, "refs/") &&
+                           !check_refname_format(sb_contents->buf, 0)) {
+                               strbuf_swap(sb_refname, sb_contents);
+                               refname = sb_refname->buf;
                                if (flags)
                                        *flags |= REF_ISSYMREF;
                                if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
@@ -1695,28 +1708,26 @@ static const char *resolve_ref_unsafe_1(const char *refname,
                        else
                                return NULL;
                }
-               len = read_in_full(fd, buffer, sizeof(buffer)-1);
-               if (len < 0) {
+               strbuf_reset(sb_contents);
+               if (strbuf_read(sb_contents, fd, 256) < 0) {
                        int save_errno = errno;
                        close(fd);
                        errno = save_errno;
                        return NULL;
                }
                close(fd);
-               while (len && isspace(buffer[len-1]))
-                       len--;
-               buffer[len] = '\0';
+               strbuf_rtrim(sb_contents);
 
                /*
                 * Is it a symbolic ref?
                 */
-               if (!starts_with(buffer, "ref:")) {
+               if (!starts_with(sb_contents->buf, "ref:")) {
                        /*
                         * Please note that FETCH_HEAD has a second
                         * line containing other data.
                         */
-                       if (get_sha1_hex(buffer, sha1) ||
-                           (buffer[40] != '\0' && !isspace(buffer[40]))) {
+                       if (get_sha1_hex(sb_contents->buf, sha1) ||
+                           (sb_contents->buf[40] != '\0' && !isspace(sb_contents->buf[40]))) {
                                if (flags)
                                        *flags |= REF_ISBROKEN;
                                errno = EINVAL;
@@ -1731,10 +1742,12 @@ static const char *resolve_ref_unsafe_1(const char *refname,
                }
                if (flags)
                        *flags |= REF_ISSYMREF;
-               buf = buffer + 4;
+               buf = sb_contents->buf + 4;
                while (isspace(*buf))
                        buf++;
-               refname = strcpy(refname_buffer, buf);
+               strbuf_reset(sb_refname);
+               strbuf_addstr(sb_refname, buf);
+               refname = sb_refname->buf;
                if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
                        hashclr(sha1);
                        return refname;
@@ -1756,10 +1769,15 @@ static const char *resolve_ref_unsafe_1(const char *refname,
 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
                               unsigned char *sha1, int *flags)
 {
+       static struct strbuf sb_refname = STRBUF_INIT;
+       struct strbuf sb_contents = STRBUF_INIT;
        struct strbuf sb_path = STRBUF_INIT;
-       const char *ret = resolve_ref_unsafe_1(refname, resolve_flags,
-                                              sha1, flags, &sb_path);
+       const char *ret;
+
+       ret = resolve_ref_1(refname, resolve_flags, sha1, flags,
+                           &sb_refname, &sb_path, &sb_contents);
        strbuf_release(&sb_path);
+       strbuf_release(&sb_contents);
        return ret;
 }
 
@@ -2108,6 +2126,15 @@ int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
        return do_for_each_ref(&ref_cache, 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(&ref_cache, 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)
 {
@@ -2190,8 +2217,7 @@ int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
 
        if (!has_glob_specials(pattern)) {
                /* Append implied '/' '*' if not present. */
-               if (real_pattern.buf[real_pattern.len - 1] != '/')
-                       strbuf_addch(&real_pattern, '/');
+               strbuf_complete(&real_pattern, '/');
                /* No need to check for '*', there is none. */
                strbuf_addch(&real_pattern, '*');
        }
@@ -2431,8 +2457,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
                strbuf_git_path(&orig_ref_file, "%s", orig_refname);
                if (remove_empty_directories(&orig_ref_file)) {
                        last_errno = errno;
-                       if (!verify_refname_available(orig_refname, extras, skip,
-                                                     get_loose_refs(&ref_cache), err))
+                       if (!verify_refname_available_dir(orig_refname, extras, skip,
+                                                         get_loose_refs(&ref_cache), err))
                                strbuf_addf(err, "there are still refs under '%s'",
                                            orig_refname);
                        goto error_return;
@@ -2445,8 +2471,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
        if (!refname) {
                last_errno = errno;
                if (last_errno != ENOTDIR ||
-                   !verify_refname_available(orig_refname, extras, skip,
-                                             get_loose_refs(&ref_cache), err))
+                   !verify_refname_available_dir(orig_refname, extras, skip,
+                                                 get_loose_refs(&ref_cache), err))
                        strbuf_addf(err, "unable to resolve reference %s: %s",
                                    orig_refname, strerror(last_errno));
 
@@ -2459,8 +2485,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
         * our refname.
         */
        if (is_null_oid(&lock->old_oid) &&
-           verify_refname_available(refname, extras, skip,
-                                    get_packed_refs(&ref_cache), err)) {
+           verify_refname_available_dir(refname, extras, skip,
+                                        get_packed_refs(&ref_cache), err)) {
                last_errno = ENOTDIR;
                goto error_return;
        }
@@ -2662,6 +2688,10 @@ static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
        struct ref_entry *packed_entry;
        int is_tag_ref = starts_with(entry->name, "refs/tags/");
 
+       /* Do not pack per-worktree refs: */
+       if (ref_type(entry->name) != REF_TYPE_NORMAL)
+               return 0;
+
        /* ALWAYS pack tags */
        if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
                return 0;
@@ -2692,7 +2722,7 @@ static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
                int namelen = strlen(entry->name) + 1;
                struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
                hashcpy(n->sha1, entry->u.value.oid.hash);
-               strcpy(n->name, entry->name);
+               memcpy(n->name, entry->name, namelen); /* includes NUL */
                n->next = cb->ref_to_prune;
                cb->ref_to_prune = n;
        }
@@ -2856,7 +2886,8 @@ static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
 
 static int is_per_worktree_ref(const char *refname)
 {
-       return !strcmp(refname, "HEAD");
+       return !strcmp(refname, "HEAD") ||
+               starts_with(refname, "refs/bisect/");
 }
 
 static int is_pseudoref_syntax(const char *refname)
@@ -3079,6 +3110,40 @@ out:
        return ret;
 }
 
+/*
+ * Return 0 if a reference named refname could be created without
+ * conflicting with the name of an existing reference. Otherwise,
+ * return a negative value and write an explanation to err. If extras
+ * is non-NULL, it is a list of additional refnames with which refname
+ * is not allowed to conflict. If skip is non-NULL, ignore potential
+ * conflicts with refs in skip (e.g., because they are scheduled for
+ * deletion in the same operation). Behavior is undefined if the same
+ * name is listed in both extras and skip.
+ *
+ * Two reference names conflict if one of them exactly matches the
+ * leading components of the other; e.g., "foo/bar" conflicts with
+ * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
+ * "foo/barbados".
+ *
+ * extras and skip must be sorted.
+ */
+static int verify_refname_available(const char *newname,
+                                   struct string_list *extras,
+                                   struct string_list *skip,
+                                   struct strbuf *err)
+{
+       struct ref_dir *packed_refs = get_packed_refs(&ref_cache);
+       struct ref_dir *loose_refs = get_loose_refs(&ref_cache);
+
+       if (verify_refname_available_dir(newname, extras, skip,
+                                        packed_refs, err) ||
+           verify_refname_available_dir(newname, extras, skip,
+                                        loose_refs, err))
+               return -1;
+
+       return 0;
+}
+
 static int rename_ref_available(const char *oldname, const char *newname)
 {
        struct string_list skip = STRING_LIST_INIT_NODUP;
@@ -3086,10 +3151,7 @@ static int rename_ref_available(const char *oldname, const char *newname)
        int ret;
 
        string_list_insert(&skip, oldname);
-       ret = !verify_refname_available(newname, NULL, &skip,
-                                       get_packed_refs(&ref_cache), &err)
-               && !verify_refname_available(newname, NULL, &skip,
-                                            get_loose_refs(&ref_cache), &err);
+       ret = !verify_refname_available(newname, NULL, &skip, &err);
        if (!ret)
                error("%s", err.buf);
 
@@ -3227,7 +3289,7 @@ static int commit_ref(struct ref_lock *lock)
  * large, while cleaning up the whitespaces.  Especially, convert LF to space,
  * because reflog file is one line per entry.
  */
-static int copy_msg(char *buf, const char *msg)
+static int copy_reflog_msg(char *buf, const char *msg)
 {
        char *cp = buf;
        char c;
@@ -3326,12 +3388,12 @@ static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
        msglen = msg ? strlen(msg) : 0;
        maxlen = strlen(committer) + msglen + 100;
        logrec = xmalloc(maxlen);
-       len = sprintf(logrec, "%s %s %s\n",
-                     sha1_to_hex(old_sha1),
-                     sha1_to_hex(new_sha1),
-                     committer);
+       len = xsnprintf(logrec, maxlen, "%s %s %s\n",
+                       sha1_to_hex(old_sha1),
+                       sha1_to_hex(new_sha1),
+                       committer);
        if (msglen)
-               len += copy_msg(logrec + len - 1, msg) - 1;
+               len += copy_reflog_msg(logrec + len - 1, msg) - 1;
 
        written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
        free(logrec);
@@ -3981,10 +4043,10 @@ void ref_transaction_free(struct ref_transaction *transaction)
 static struct ref_update *add_update(struct ref_transaction *transaction,
                                     const char *refname)
 {
-       size_t len = strlen(refname);
-       struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
+       size_t len = strlen(refname) + 1;
+       struct ref_update *update = xcalloc(1, sizeof(*update) + len);
 
-       strcpy((char *)update->refname, refname);
+       memcpy((char *)update->refname, refname, len); /* includes NUL */
        ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
        transaction->updates[transaction->nr++] = update;
        return update;
@@ -4293,8 +4355,6 @@ static int ref_present(const char *refname,
 int initial_ref_transaction_commit(struct ref_transaction *transaction,
                                   struct strbuf *err)
 {
-       struct ref_dir *loose_refs = get_loose_refs(&ref_cache);
-       struct ref_dir *packed_refs = get_packed_refs(&ref_cache);
        int ret = 0, i;
        int n = transaction->nr;
        struct ref_update **updates = transaction->updates;
@@ -4337,10 +4397,7 @@ int initial_ref_transaction_commit(struct ref_transaction *transaction,
                        die("BUG: initial ref transaction with old_sha1 set");
                if (verify_refname_available(update->refname,
                                             &affected_refnames, NULL,
-                                            loose_refs, err) ||
-                   verify_refname_available(update->refname,
-                                            &affected_refnames, NULL,
-                                            packed_refs, err)) {
+                                            err)) {
                        ret = TRANSACTION_NAME_CONFLICT;
                        goto cleanup;
                }