utf8::upgrade: Don't coerce undef arg

This fixes GH #20419
Perl · Oct 28, 2022 · 6ea2a51 · 6ea2a51
1 parent fdc8a0b
commit 6ea2a51
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/universal.c b/universal.c
@@ -593,10 +593,13 @@ 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);
+        if (LIKELY(sv && SvANY(sv))) {
+            RETVAL = sv_utf8_upgrade(sv);
+        }
+
         XSprePUSH; PUSHi((IV)RETVAL);
     }
     XSRETURN(1);