From: Alexander Bluhm <alexander.bluhm@gmx.net>
Date: Sat, 20 Aug 2016 05:57:13 +0000 (-0700)
Subject: On OpenBSD 6.0 the test t/exotic_names.t fails sometimes. (RT#117072)
X-Git-Tag: v0.20~2
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=f90d35bed922539c764e57e02848e9e485e14242;p=p5sagit%2FSub-Name.git

On OpenBSD 6.0 the test t/exotic_names.t fails sometimes. (RT#117072)

Program received signal SIGSEGV, Segmentation fault.
0x00000a9bf44b686a in XS_Sub__Name_subname (cv=Variable "cv" is not available.
) at Name.xs:72
72                      else if (*s && s[-1] == '\'') {

(gdb) print s
$1 = 0xa9c6d507000 "test::SOME_y_STASH::SOME_y_NAME"

With OpenBSD malloc randomisation the storage for nameptr is sometimes
at the beginning of the page.  Then accessing s[-1] with s == nameptr
is fatal.
---

diff --git a/Name.xs b/Name.xs
index 3484085..9a4d493 100644
--- a/Name.xs
+++ b/Name.xs
@@ -63,13 +63,13 @@ subname(name, sub)
 		croak("Not a subroutine reference");
 
 	for (s = nameptr; s <= nameptr + namelen; s++) {
-		if (*s == ':' && s[-1] == ':') {
+		if (s > nameptr && *s == ':' && s[-1] == ':') {
 			end = s - 1;
 			begin = ++s;
 			if (seen_quote)
 				need_subst++;
 		}
-		else if (*s && s[-1] == '\'') {
+		else if (s > nameptr && *s != '\0' && s[-1] == '\'') {
 			end = s - 1;
 			begin = s;
 			if (seen_quote++)