From 4f82acce17ca51b03bea2abe3eefb7c3026138fe Mon Sep 17 00:00:00 2001 From: David Bremner Date: Sat, 25 Nov 2023 08:33:52 -0400 Subject: [PATCH] lib/string_map: simulate stable sorting qsort(3) does not promise stability, and recent versions of glibc have been showing more unstable behaviour [2]. Michael Gruber observed [1] test breakage due to changing output order for message properties. We provide a sorting order of (key,value) pairs that _looks_ stable by breaking ties based on value if keys are equal. Internally there may be some instability in the case of duplicate (key,value) pairs, but it should not be observable via the iterator API. [1]: id:CAA19uiSHjVFmwH0pMC7WwDYCOSzu3yqNbuYhu3ZMeNNRh313eA@mail.gmail.com [2]: id:87msv3i44u.fsf@oldenburg.str.redhat.com --- lib/string-map.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/string-map.c b/lib/string-map.c index e3a81b4f..99bc2ea2 100644 --- a/lib/string-map.c +++ b/lib/string-map.c @@ -86,10 +86,14 @@ _notmuch_string_map_append (notmuch_string_map_t *map, static int cmppair (const void *pa, const void *pb) { + int cmp = 0; notmuch_string_pair_t *a = (notmuch_string_pair_t *) pa; notmuch_string_pair_t *b = (notmuch_string_pair_t *) pb; - return strcmp (a->key, b->key); + cmp = strcmp (a->key, b->key); + if (cmp == 0) + cmp = strcmp (a->value, b->value); + return cmp; } static void