From 73031816b5ef6a74869c06e84bb621841a623d0a Mon Sep 17 00:00:00 2001
From: Nicholas Clark <nick@ccl4.org>
Date: Fri, 5 Oct 2007 21:46:39 +0000
Subject: [PATCH] Eliminate the Perl_sv_catpvf() in TRIE_STORE_REVCHAR

p4raw-id: //depot/perl@32036
---
 regcomp.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/regcomp.c b/regcomp.c
index 8757eb1..b302561 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -1163,11 +1163,19 @@ is the recommended Unicode-aware way of saying
 
 #define TRIE_STORE_REVCHAR                                                 \
     STMT_START {                                                           \
-	SV *tmp = newSVpvs("");                                            \
-	if (UTF) SvUTF8_on(tmp);                                           \
-	Perl_sv_catpvf( aTHX_ tmp, "%c", (int)uvc );                       \
-	av_push( revcharmap, tmp );                                        \
-    } STMT_END
+	if (UTF) {							   \
+	    SV *zlopp = newSV(2);					   \
+	    char *flrbbbbb = SvPVX(zlopp);				   \
+	    const char *const kapow = uvuni_to_utf8(flrbbbbb, uvc & 0xFF); \
+	    SvCUR_set(zlopp, kapow - flrbbbbb);				   \
+	    SvPOK_on(zlopp);						   \
+	    SvUTF8_on(zlopp);						   \
+	    av_push(revcharmap, zlopp);					   \
+	} else {							   \
+	    unsigned char ooooff = uvc;					   \
+	    av_push(revcharmap, newSVpvn(&ooooff, 1));			   \
+	}								   \
+        } STMT_END
 
 #define TRIE_READ_CHAR STMT_START {                                           \
     wordlen++;                                                                \
-- 
2.7.4