Bug#6787 LIKE not working properly with _ and utf8 data

mysql-test/r/ctype_uca.result

@@ -19,6 +19,9 @@ select 'a ' = 'a\t', 'a ' < 'a\t', 'a ' > 'a\t';
 select 'a  a' > 'a', 'a  \t' < 'a';
 'a  a' > 'a'	'a  \t' < 'a'
 1	1
+select 'c' like '\_' as want0;
+want0
+0
 CREATE TABLE t (
 c char(20) NOT NULL
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

mysql-test/r/ctype_utf8.result

@@ -814,3 +814,6 @@ t2	CREATE TABLE `t2` (
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t2;
 drop table t1;
+select 'c' like '\_' as want0;
+want0
+0

mysql-test/t/ctype_uca.test

@@ -24,6 +24,11 @@ select 'a ' = 'a\t', 'a ' < 'a\t', 'a ' > 'a\t';
 
 select 'a  a' > 'a', 'a  \t' < 'a';
 
+#
+# Bug #6787 LIKE not working properly with _ and utf8 data
+#
+select 'c' like '\_' as want0; 
+
 #
 # Bug #5679 utf8_unicode_ci LIKE--trailing % doesn't equal zero characters
 #

mysql-test/t/ctype_utf8.test

@@ -660,3 +660,9 @@ create table t2 select concat(a,_utf8'') as a, concat(b,_utf8'')as b from t1;
 show create table t2;
 drop table t2;
 drop table t1;
+
+#
+# Bug #6787 LIKE not working properly with _ and utf8 data
+#
+select 'c' like '\_' as want0; 
+

strings/ctype-uca.c

@@ -7288,6 +7288,7 @@ int my_wildcmp_uca(CHARSET_INFO *cs,
   {
     while (1)
     {
+      my_bool escaped= 0;
       if ((scan= mb_wc(cs, &w_wc, (const uchar*)wildstr,
 		       (const uchar*)wildend)) <= 0)
 	return 1;
@@ -7305,6 +7306,7 @@ int my_wildcmp_uca(CHARSET_INFO *cs,
 			(const uchar*)wildend)) <= 0)
           return 1;
         wildstr+= scan;
+        escaped= 1;
       }
       
       if ((scan= mb_wc(cs, &s_wc, (const uchar*)str,
@@ -7312,7 +7314,7 @@ int my_wildcmp_uca(CHARSET_INFO *cs,
         return 1;
       str+= scan;
       
-      if (w_wc == (my_wc_t)w_one)
+      if (!escaped && w_wc == (my_wc_t)w_one)
       {
         result= 1;				/* Found an anchor char */
       }

strings/ctype-utf8.c

@@ -1545,18 +1545,11 @@ int my_wildcmp_unicode(CHARSET_INFO *cs,
   {
     while (1)
     {
+      my_bool escaped= 0;
       if ((scan= mb_wc(cs, &w_wc, (const uchar*)wildstr,
                        (const uchar*)wildend)) <= 0)
         return 1;
 
-      if (w_wc ==  (my_wc_t)escape)
-      {
-        wildstr+= scan;
-        if ((scan= mb_wc(cs,&w_wc, (const uchar*)wildstr,
-                         (const uchar*)wildend)) <= 0)
-          return 1;
-      }
-      
       if (w_wc == (my_wc_t)w_many)
       {
         result= 1;				/* Found an anchor char */
@@ -1564,12 +1557,21 @@ int my_wildcmp_unicode(CHARSET_INFO *cs,
       }
 
       wildstr+= scan;
+      if (w_wc ==  (my_wc_t)escape)
+      {
+        if ((scan= mb_wc(cs, &w_wc, (const uchar*)wildstr,
+                         (const uchar*)wildend)) <= 0)
+          return 1;
+        wildstr+= scan;
+        escaped= 1;
+      }
+      
       if ((scan= mb_wc(cs, &s_wc, (const uchar*)str,
-                       (const uchar*)str_end)) <=0)
+                       (const uchar*)str_end)) <= 0)
         return 1;
       str+= scan;
       
-      if (w_wc == (my_wc_t)w_one)
+      if (!escaped && w_wc == (my_wc_t)w_one)
       {
         result= 1;				/* Found an anchor char */
       }