croaking for readonly SVs in Perl_sv_utf8_upgrade_flags was a mistake

back this out until we have a tangible policy

p4raw-id: //depot/perl@22483

diff --git a/sv.c b/sv.c
index ad9c33a..70e157d 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -3477,10 +3477,6 @@ Perl_sv_utf8_upgrade_flags(pTHX_ register SV *sv, I32 flags)
         sv_force_normal_flags(sv, 0);
     }
 
-    if (SvREADONLY(sv)) {
-       Perl_croak(aTHX_ PL_no_modify);
-    }
-
     if (PL_encoding && !(flags & SV_UTF8_NO_ENCODING))
         sv_recode_to_utf8(sv, PL_encoding);
     else { /* Assume Latin-1/EBCDIC */