[commit] master: don't try to qsort() NULL array

[ossi <os...@us...>]

commit ceb0fa9803b27057c7a8413cf50a51f428f5d792
Author: Oswald Buddenhagen <os...@us...>
Date:   Thu Jul 4 09:09:17 2024 +0200

    don't try to qsort() NULL array
    
    while this actually works due to the array size being zero, it's
    undefined behavior which makes gcc eliminate a subsequent null check in
    the calling function.

 src/main_sync.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/main_sync.c b/src/main_sync.c
index 226e324..fff944c 100644
--- a/src/main_sync.c
+++ b/src/main_sync.c
@@ -186,7 +186,8 @@ filter_boxes( string_list_t *boxes, const char *prefix, string_list_t *patterns
 			boxarr[num] = NULL;
 		}
 	}
-	qsort( boxarr, num, sizeof(*boxarr), cmp_box_names );
+	if (boxarr)
+		qsort( boxarr, num, sizeof(*boxarr), cmp_box_names );
 	return boxarr;
 }