Sort indexes: Don't assert-crash with broken sort IDs.

--HG--
branch : HEAD

diff --git a/src/lib-storage/index/index-sort-string.c b/src/lib-storage/index/index-sort-string.c
index 17a839e592a161eb5792292f44d591ff00bdeb19..775b7389c0f7e51fc130a028a14abe38b48647ec 100644 (file)
--- a/src/lib-storage/index/index-sort-string.c
+++ b/src/lib-storage/index/index-sort-string.c
@@ -607,7 +607,11 @@ index_sort_add_ids_range(struct sort_string_context *ctx,
                           messages */
                        skip = (right_sort_id - left_sort_id) /
                                (right_idx - i + 2);
-                       i_assert(skip > 0);
+                       if (skip == 0) {
+                               /* broken sort IDs (we previously assigned
+                                  left_sort_id=right_sort_id) */
+                               return -1;
+                       }
                        left_sort_id += skip;
                        i_assert(left_sort_id < right_sort_id);