utf8.c: Don't do ++ in macro parameter

The formal parameter gets evaluated multiple times on an EBCDIC
platform, thus incrementing more than the intended once.

1 files changed, 3 insertions, 2 deletions

diff --git a/utf8.c b/utf8.c
index 1570fc80f0..64da27db1d 100644
--- a/utf8.c
+++ b/utf8.c
@@ -1335,9 +1335,10 @@ Perl_bytes_from_utf8(pTHX_ const U8 *s, STRLEN *len, bool *is_utf8)
     s = start; start = d;
     while (s < send) {
 	U8 c = *s++;
-	if (!UTF8_IS_INVARIANT(c)) {
+	if (! UTF8_IS_INVARIANT(c)) {
 	    /* Then it is two-byte encoded */
-	    c = TWO_BYTE_UTF8_TO_NATIVE(c, *s++);
+	    c = TWO_BYTE_UTF8_TO_NATIVE(c, *s);
+            s++;
 	}
 	*d++ = c;
     }