X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/bfe645c1570343d3adca657ab67998e122ca8792..4fab92fbc2b63bac2d89c1dae69fa1845cb640b7:/src/src/utf8.c

diff --git a/src/src/utf8.c b/src/src/utf8.c
index 84ad1dc18..e394db0a8 100644
--- a/src/src/utf8.c
+++ b/src/src/utf8.c
@@ -18,7 +18,7 @@ BOOL
 string_is_utf8(const uschar * s)
 {
 uschar c;
-while ((c = *s++)) if (c & 0x80) return TRUE;
+if (s) while ((c = *s++)) if (c & 0x80) return TRUE;
 return FALSE;
 }