lib-storage: If mailbox_rename() isn't possible and mail_debug=yes, log the reason...

diff --git a/src/lib-storage/mail-storage.c b/src/lib-storage/mail-storage.c
index c7e7773604d54b1e35fde62235fd12af8c62f244..a23df67a3007163ebe908c089980b1a848990503 100644 (file)
--- a/src/lib-storage/mail-storage.c
+++ b/src/lib-storage/mail-storage.c
@@ -805,15 +805,24 @@ int mailbox_delete(struct mailbox *box)
 
 static bool
 mail_storages_rename_compatible(struct mail_storage *storage1,
-                               struct mail_storage *storage2)
+                               struct mail_storage *storage2,
+                               const char **error_r)
 {
        if (storage1 == storage2)
                return TRUE;
 
-       if (strcmp(storage1->name, storage2->name) != 0)
+       if (strcmp(storage1->name, storage2->name) != 0) {
+               *error_r = t_strdup_printf("storage %s != %s",
+                                          storage1->name, storage2->name);
                return FALSE;
-       if ((storage1->class_flags & MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT) != 0)
+       }
+       if ((storage1->class_flags & MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT) != 0) {
+               /* e.g. mdbox where all mails are in storage/ directory and
+                  they can't be easily moved from there. */
+               *error_r = t_strdup_printf("storage %s uses unique root",
+                                          storage1->name);
                return FALSE;
+       }
        return TRUE;
 }
 
@@ -824,16 +833,29 @@ static bool nullequals(const void *p1, const void *p2)
 
 static bool
 mailbox_lists_rename_compatible(struct mailbox_list *list1,
-                               struct mailbox_list *list2)
+                               struct mailbox_list *list2,
+                               const char **error_r)
 {
-       return nullequals(list1->set.alt_dir, list2->set.alt_dir) &&
-               nullequals(list1->set.index_dir, list2->set.index_dir) &&
-               nullequals(list1->set.control_dir, list2->set.control_dir);
+       if (!nullequals(list1->set.alt_dir, list2->set.alt_dir)) {
+               *error_r = "alt dirs don't match";
+               return FALSE;
+       }
+       if (!nullequals(list1->set.index_dir, list2->set.index_dir)) {
+               *error_r = "index dirs don't match";
+               return FALSE;
+       }
+       if (!nullequals(list1->set.control_dir, list2->set.control_dir)) {
+               *error_r = "control dirs don't match";
+               return FALSE;
+       }
+       return TRUE;
 }
 
 int mailbox_rename(struct mailbox *src, struct mailbox *dest,
                   bool rename_children)
 {
+       const char *error = NULL;
+
        if (!mailbox_list_is_valid_existing_name(src->list, src->name) ||
            *src->name == '\0' ||
            !mailbox_list_is_valid_create_name(dest->list, dest->name)) {
@@ -841,8 +863,14 @@ int mailbox_rename(struct mailbox *src, struct mailbox *dest,
                                       "Invalid mailbox name");
                return -1;
        }
-       if (!mail_storages_rename_compatible(src->storage, dest->storage) ||
-           !mailbox_lists_rename_compatible(src->list, dest->list)) {
+       if (!mail_storages_rename_compatible(src->storage,
+                                            dest->storage, &error) ||
+           !mailbox_lists_rename_compatible(src->list,
+                                            dest->list, &error)) {
+               if (src->storage->set->mail_debug) {
+                       i_debug("Can't rename '%s' to '%s': %s",
+                               src->vname, dest->vname, error);
+               }
                mail_storage_set_error(src->storage, MAIL_ERROR_NOTPOSSIBLE,
                        "Can't rename mailboxes across specified storages.");
                return -1;