From: Nicholas Clark <nick@ccl4.org>
Date: Thu, 22 Oct 2009 19:17:54 +0000 (+0100)
Subject: In S_utf16_textfilter() replace sv_chop() with code, as we move 1 byte at most.
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=e07286ed3e670b1b54d58add2acfdf6985372bf6;p=p5sagit%2Fp5-mst-13.2.git

In S_utf16_textfilter() replace sv_chop() with code, as we move 1 byte at most.
---

diff --git a/toke.c b/toke.c
index f105505..d83ac6a 100644
--- a/toke.c
+++ b/toke.c
@@ -12871,7 +12871,15 @@ S_utf16_textfilter(pTHX_ int idx, SV *sv, int maxlen)
 	SvCUR_set(utf8_buffer, have + newlen);
 	*end = '\0';
 
-	sv_chop(utf16_buffer, SvPVX(utf16_buffer) + chars * 2);
+	/* No need to keep this SV "well-formed" with a '\0' after the end, as
+	   it's private to us, and utf16_to_utf8{,reversed} take a
+	   (pointer,length) pair, rather than a NUL-terminated string.  */
+	if(SvCUR(utf16_buffer) & 1) {
+	    *SvPVX(utf16_buffer) = SvEND(utf16_buffer)[-1];
+	    SvCUR_set(utf16_buffer, 1);
+	} else {
+	    SvCUR_set(utf16_buffer, 0);
+	}
     }
     DEBUG_P(PerlIO_printf(Perl_debug_log,
 			  "utf16_textfilter: returns, status=%"IVdf" utf16=%"UVuf" utf8=%"UVuf"\n",