[perl #131263] clear the UTF8 flag on a glob if it isn't UTF8

tonycoz · tonycoz · commit 1097da16b21f · 2017-06-07T15:00:26.000+10:00
Previously sv_2pv_flags() would set the UTF8 flag on a glob if it
had a UTF8 name, but wouldn't clear tha flag if it didn't.

This meant a name change, eg. if assigned another glob, from a UTF8
name to a non-UTF8 name would leave the flag set.
diff --git a/sv.c b/sv.c
@@ -3185,6 +3185,8 @@ Perl_sv_2pv_flags(pTHX_ SV *const sv, STRLEN *const lp, const I32 flags)
 	assert(SvPOK(buffer));
 	if (SvUTF8(buffer))
 	    SvUTF8_on(sv);
+        else
+            SvUTF8_off(sv);
 	if (lp)
 	    *lp = SvCUR(buffer);
 	return SvPVX(buffer);
diff --git a/t/op/gv.t b/t/op/gv.t
@@ -12,7 +12,7 @@ BEGIN {
 
 use warnings;
 
-plan(tests => 282);
+plan(tests => 284);
 
 # type coercion on assignment
 $foo = 'foo';
@@ -1170,6 +1170,14 @@ SKIP: {
     is ($? & 127, 0,"[perl #128597] No crash when gp_free calls ckWARN_d");
 }
 
+{
+    # [perl #131263]
+    *sym = "\N{U+0080}";
+    ok(*sym eq "*main::\N{U+0080}", "utf8 flag properly set");
+    *sym = "\xC3\x80";
+    ok(*sym eq "*main::\xC3\x80", "utf8 flag properly cleared");
+}
+
 # test gv_try_downgrade()
 # If a GV can be stored in a stash in a compact, non-GV form, then
 # whenever ops are freed which reference the GV, an attempt is made to
