backport from head

(This used to be commit e05eb1437054286f14714c46099e867a396dac7d)

diff --git a/source3/lib/replace.c b/source3/lib/replace.c
index cd48b8d160fe4f7f249694492c62afb886351c1f..fe1cfc04eb11c2edd4487782277de60b117fd15a 100644 (file)
--- a/source3/lib/replace.c
+++ b/source3/lib/replace.c
@@ -65,6 +65,9 @@ ftruncate for operating systems that don't have it
        size_t len2 = strlen(s);
        size_t ret = len1 + len2;
 
+       if (len1 >= bufsize) {
+               return 0;
+       }
        if (len1+len2 >= bufsize) {
                len2 = bufsize - (len1+1);
        }