verify_refname_available(): report errors via a "struct strbuf *err"

It shouldn't be spewing errors directly to stderr.

For now, change its callers to spew the errors to stderr.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

diff --git a/refs.c b/refs.c
index 703e93dec993e217fdb155cf7e9d79d33fb157d2..43e7bdd896469b846b3c53c873f5ae3ebc2a1590 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -860,12 +860,12 @@ 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. 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.
+ * 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
@@ -877,7 +877,8 @@ static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
 static int verify_refname_available(const char *refname,
                                    const struct string_list *extras,
                                    const struct string_list *skip,
-                                   struct ref_dir *dir)
+                                   struct ref_dir *dir,
+                                   struct strbuf *err)
 {
        const char *slash;
        int pos;
@@ -889,6 +890,8 @@ static int verify_refname_available(const char *refname,
         * refname is "refs/foo/bar".
         */
 
+       assert(err);
+
        strbuf_grow(&dirname, strlen(refname) + 1);
        for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
                /* Expand dirname to the new prefix, not including the trailing slash: */
@@ -908,16 +911,16 @@ static int verify_refname_available(const char *refname,
                                 * a proper prefix of refname; e.g.,
                                 * "refs/foo", and is not in skip.
                                 */
-                               error("'%s' exists; cannot create '%s'",
-                                     dirname.buf, refname);
+                               strbuf_addf(err, "'%s' exists; cannot create '%s'",
+                                           dirname.buf, refname);
                                goto cleanup;
                        }
                }
 
                if (extras && string_list_has_string(extras, dirname.buf) &&
                    (!skip || !string_list_has_string(skip, dirname.buf))) {
-                       error("cannot process '%s' and '%s' at the same time",
-                             refname, dirname.buf);
+                       strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
+                                   refname, dirname.buf);
                        goto cleanup;
                }
 
@@ -976,8 +979,8 @@ static int verify_refname_available(const char *refname,
                        dir = get_ref_dir(dir->entries[pos]);
                        sort_ref_dir(dir);
                        if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) {
-                               error("'%s' exists; cannot create '%s'",
-                                     data.conflicting_refname, refname);
+                               strbuf_addf(err, "'%s' exists; cannot create '%s'",
+                                           data.conflicting_refname, refname);
                                goto cleanup;
                        }
                }
@@ -1000,8 +1003,8 @@ static int verify_refname_available(const char *refname,
                                break;
 
                        if (!skip || !string_list_has_string(skip, extra_refname)) {
-                               error("cannot process '%s' and '%s' at the same time",
-                                     refname, extra_refname);
+                               strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
+                                           refname, extra_refname);
                                goto cleanup;
                        }
                }
@@ -2340,6 +2343,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
        int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
        int resolve_flags = 0;
        int attempts_remaining = 3;
+       struct strbuf err = STRBUF_INIT;
 
        lock = xcalloc(1, sizeof(struct ref_lock));
        lock->lock_fd = -1;
@@ -2384,7 +2388,9 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
         * our refname.
         */
        if (is_null_sha1(lock->old_sha1) &&
-           verify_refname_available(refname, extras, skip, get_packed_refs(&ref_cache))) {
+           verify_refname_available(refname, extras, skip,
+                                    get_packed_refs(&ref_cache), &err)) {
+               error("%s", err.buf);
                last_errno = ENOTDIR;
                goto error_return;
        }
@@ -2425,10 +2431,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
                         */
                        goto retry;
                else {
-                       struct strbuf err = STRBUF_INIT;
                        unable_to_lock_message(ref_file, errno, &err);
                        error("%s", err.buf);
-                       strbuf_release(&err);
                        goto error_return;
                }
        }
@@ -2436,6 +2440,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 
  error_return:
        unlock_ref(lock);
+       strbuf_release(&err);
        errno = last_errno;
        return NULL;
 }
@@ -2822,14 +2827,19 @@ static int rename_tmp_log(const char *newrefname)
 static int rename_ref_available(const char *oldname, const char *newname)
 {
        struct string_list skip = STRING_LIST_INIT_NODUP;
+       struct strbuf err = STRBUF_INIT;
        int ret;
 
        string_list_insert(&skip, oldname);
        ret = !verify_refname_available(newname, NULL, &skip,
-                                       get_packed_refs(&ref_cache))
+                                       get_packed_refs(&ref_cache), &err)
                && !verify_refname_available(newname, NULL, &skip,
-                                            get_loose_refs(&ref_cache));
+                                            get_loose_refs(&ref_cache), &err);
+       if (!ret)
+               error("%s", err.buf);
+
        string_list_clear(&skip, 0);
+       strbuf_release(&err);
        return ret;
 }