From cfa78c2645d3a0c3eaf02a256f63d2d284ed2b3b Mon Sep 17 00:00:00 2001
From: unknown <bar@mysql.com>
Date: Fri, 18 Feb 2005 16:10:12 +0400
Subject: [PATCH] Bug #7878 with utf_general_ci, equals (=) has problem with
 accent insensitivity Backporting Monty's fix for 5.0 into 4.1.

---
 include/my_base.h                   |  1 +
 myisam/mi_rnext_same.c              |  8 ++++++--
 mysql-test/r/ctype_latin1_de.result | 12 ++++++++++++
 mysql-test/t/ctype_latin1_de.test   | 16 ++++++++++++++++
 4 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/include/my_base.h b/include/my_base.h
index 7290d0da09b..d702ec45140 100644
--- a/include/my_base.h
+++ b/include/my_base.h
@@ -340,6 +340,7 @@ enum ha_base_keytype {
 #define HA_STATE_BUFF_SAVED	512	/* If current keybuff is info->buff */
 #define HA_STATE_ROW_CHANGED	1024	/* To invalide ROW cache */
 #define HA_STATE_EXTEND_BLOCK	2048
+#define HA_STATE_RNEXT_SAME	4096	/* rnext_same was called */
 
 enum en_fieldtype {
   FIELD_LAST=-1,FIELD_NORMAL,FIELD_SKIP_ENDSPACE,FIELD_SKIP_PRESPACE,
diff --git a/myisam/mi_rnext_same.c b/myisam/mi_rnext_same.c
index a50c578e081..06408f57a3f 100644
--- a/myisam/mi_rnext_same.c
+++ b/myisam/mi_rnext_same.c
@@ -57,7 +57,11 @@ int mi_rnext_same(MI_INFO *info, byte *buf)
 #endif
     case HA_KEY_ALG_BTREE:
     default:
-      memcpy(info->lastkey2,info->lastkey,info->last_rkey_length);
+      if (!(info->update & HA_STATE_RNEXT_SAME))
+      {
+        /* First rnext_same; Store old key */
+        memcpy(info->lastkey2,info->lastkey,info->last_rkey_length);
+      }
       for (;;)
       {
         if ((error=_mi_search_next(info,keyinfo,info->lastkey,
@@ -81,7 +85,7 @@ int mi_rnext_same(MI_INFO *info, byte *buf)
     rw_unlock(&info->s->key_root_lock[inx]);
 	/* Don't clear if database-changed */
   info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED);
-  info->update|= HA_STATE_NEXT_FOUND;
+  info->update|= HA_STATE_NEXT_FOUND | HA_STATE_RNEXT_SAME;
 
   if (error)
   {
diff --git a/mysql-test/r/ctype_latin1_de.result b/mysql-test/r/ctype_latin1_de.result
index 6df9d963498..f57d8c191bf 100644
--- a/mysql-test/r/ctype_latin1_de.result
+++ b/mysql-test/r/ctype_latin1_de.result
@@ -326,3 +326,15 @@ latin1_german2_ci	6109
 latin1_german2_ci	61
 latin1_german2_ci	6120
 drop table t1;
+SET NAMES latin1;
+CREATE TABLE t1 (
+col1 varchar(255) NOT NULL default ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 collate latin1_german2_ci;
+INSERT INTO t1 VALUES ('ß'),('ss'),('ss');
+ALTER TABLE t1 ADD KEY ifword(col1);
+SELECT * FROM t1 WHERE col1='ß' ORDER BY col1, BINARY col1;
+col1
+ss
+ss
+ß
+DROP TABLE t1;
diff --git a/mysql-test/t/ctype_latin1_de.test b/mysql-test/t/ctype_latin1_de.test
index ce4fdc4e3c9..512ae88a445 100644
--- a/mysql-test/t/ctype_latin1_de.test
+++ b/mysql-test/t/ctype_latin1_de.test
@@ -116,3 +116,19 @@ SELECT FIELD('ue',s1), FIELD('
 DROP TABLE t1;
 
 -- source include/ctype_filesort.inc
+
+#
+# Bug#7878 with utf8_general_ci, equals (=) has problem with
+# accent insensitivity.
+# Although originally this problem was found with UTF8 character set,
+# '=' behaved wrong for latin1_german2_ci as well.
+# Let's check it does not work incorrect anymore.
+# 
+SET NAMES latin1;
+CREATE TABLE t1 (
+  col1 varchar(255) NOT NULL default ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1 collate latin1_german2_ci;
+INSERT INTO t1 VALUES ('ß'),('ss'),('ss');
+ALTER TABLE t1 ADD KEY ifword(col1);
+SELECT * FROM t1 WHERE col1='ß' ORDER BY col1, BINARY col1;
+DROP TABLE t1;