lib-fs: Add assert to make sure we never log "(null)" as the old error

diff --git a/src/lib-fs/fs-api.c b/src/lib-fs/fs-api.c
index 59e05a99c9141d780c37d58acd667fdb34083c72..12bce8a686799e70ca4368ee63807f946d7e1b7d 100644 (file)
--- a/src/lib-fs/fs-api.c
+++ b/src/lib-fs/fs-api.c
@@ -604,7 +604,9 @@ fs_set_verror(struct event *event, const char *fmt, va_list args)
                file = fs_file_get_error_file(file);
                char *old_error = file->last_error;
 
-               if (old_error != NULL && strcmp(old_error, new_error) == 0) {
+               if (old_error == NULL) {
+                       i_assert(!file->last_error_changed);
+               } else if (strcmp(old_error, new_error) == 0) {
                        /* identical error - ignore */
                } else if (file->last_error_changed) {
                        /* multiple fs_set_error() calls used without