utf8::upgrade: Don't coerce undef arg

This fixes GH Perl#20419
khwilliamson · Nov 2, 2022 · 6bdaa52 · 6bdaa52
1 parent fce4124
commit 6bdaa52
Showing 1 changed file with 13 additions and 3 deletions.
diff --git a/universal.c b/universal.c
@@ -593,11 +593,21 @@ XS(XS_utf8_upgrade)
         croak_xs_usage(cv, "sv");
     else {
         SV * const sv = ST(0);
-        STRLEN	RETVAL;
+        STRLEN	RETVAL = 0;
         dXSTARG;
 
-        RETVAL = sv_utf8_upgrade(sv);
-        XSprePUSH; PUSHi((IV)RETVAL);
+        XSprePUSH;
+        if (LIKELY(sv)) {
+            SvGETMAGIC(sv);
+            if (LIKELY(SvOK(sv))) {
+                RETVAL = sv_utf8_upgrade_nomg(sv);
+                PUSHi( (IV) RETVAL);
+            } else {
+                PUSHs(newSV(0));
+            }
+        } else {
+            PUSHs(newSV(0));
+        }
     }
     XSRETURN(1);
 }