From 26eb8e4b4e39aee7c1e4e9c061c9c17daaafc78b Mon Sep 17 00:00:00 2001
From: usa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 17 Aug 2015 08:58:50 +0000
Subject: merge revision(s) 51470: [Backport #11413]

	* re.c (rb_memsearch): should match only char boundaries in wide
	  character encodings.  [ruby-core:70220] [Bug #11413]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@51615 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 re.c | 44 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 38 insertions(+), 6 deletions(-)

(limited to 're.c')

diff --git a/re.c b/re.c
index d26b783466..ceb72b9377 100644
--- a/re.c
+++ b/re.c
@@ -223,6 +223,32 @@ rb_memsearch_qs_utf8(const unsigned char *xs, long m, const unsigned char *ys, l
     return -1;
 }
 
+static inline long
+rb_memsearch_wchar(const unsigned char *xs, long m, const unsigned char *ys, long n)
+{
+    const unsigned char *x = xs, x0 = *xs, *y = ys;
+    enum {char_size = 2};
+
+    for (n -= m; n > 0; n -= char_size, y += char_size) {
+	if (x0 == *y && memcmp(x+1, y+1, m-1) == 0)
+	    return y - ys;
+    }
+    return -1;
+}
+
+static inline long
+rb_memsearch_qchar(const unsigned char *xs, long m, const unsigned char *ys, long n)
+{
+    const unsigned char *x = xs, x0 = *xs, *y = ys;
+    enum {char_size = 4};
+
+    for (n -= m; n > 0; n -= char_size, y += char_size) {
+	if (x0 == *y && memcmp(x+1, y+1, m-1) == 0)
+	    return y - ys;
+    }
+    return -1;
+}
+
 long
 rb_memsearch(const void *x0, long m, const void *y0, long n, rb_encoding *enc)
 {
@@ -243,15 +269,21 @@ rb_memsearch(const void *x0, long m, const void *y0, long n, rb_encoding *enc)
 	else
 	    return -1;
     }
-    else if (m <= SIZEOF_VALUE) {
-	return rb_memsearch_ss(x0, m, y0, n);
+    else if (rb_enc_mbminlen(enc) == 1) {
+	if (m <= SIZEOF_VALUE) {
+	    return rb_memsearch_ss(x0, m, y0, n);
+	}
+	else if (enc == rb_utf8_encoding()){
+	    return rb_memsearch_qs_utf8(x0, m, y0, n);
+	}
     }
-    else if (enc == rb_utf8_encoding()){
-	return rb_memsearch_qs_utf8(x0, m, y0, n);
+    else if (rb_enc_mbminlen(enc) == 2) {
+	return rb_memsearch_wchar(x0, m, y0, n);
     }
-    else {
-	return rb_memsearch_qs(x0, m, y0, n);
+    else if (rb_enc_mbminlen(enc) == 4) {
+	return rb_memsearch_qchar(x0, m, y0, n);
     }
+    return rb_memsearch_qs(x0, m, y0, n);
 }
 
 #define REG_LITERAL FL_USER5
-- 
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