Fix SvGROW on an SV with SvLEN == 0 - copy in any existing data.

(Mis-feature discovered by Encode.)

p4raw-id: //depot/perlio@14526

1 files changed, 3 insertions, 0 deletions

diff --git a/sv.c b/sv.c
index 8f5b0a6172..217df878b7 100644
--- a/sv.c
+++ b/sv.c
@@ -1584,6 +1584,9 @@ Perl_sv_grow(pTHX_ register SV *sv, register STRLEN newlen)
 		SvREADONLY_off(sv);
 	    }
 	    New(703, s, newlen, char);
+	    if (SvPVX(sv) && SvCUR(sv)) {
+	        Move(SvPVX(sv), s, SvCUR(sv), char);
+	    }
 	}
 	SvPV_set(sv, s);
         SvLEN_set(sv, newlen);