Resolve merge from 4.1

mysql-test/r/grant_cache.result

 drop table if exists test.t1,mysqltest.t1,mysqltest.t2;
 drop database if exists mysqltest;
+set GLOBAL query_cache_size=1355776;
 reset query cache;
 flush status;
 show grants for current_user;
@@ -206,3 +207,4 @@ delete from mysql.columns_priv where user in ("mysqltest_1","mysqltest_2","mysql
 flush privileges;
 drop table test.t1,mysqltest.t1,mysqltest.t2;
 drop database mysqltest;
+set GLOBAL query_cache_size=default;

mysql-test/r/merge.result

@@ -683,3 +683,13 @@ t3	1	a	1	a	A	NULL	NULL	NULL	YES	BTREE
 t3	1	a	2	b	A	NULL	NULL	NULL	YES	BTREE	
 t3	1	a	3	c	A	NULL	NULL	NULL	YES	BTREE	
 drop table t1, t2, t3;
+CREATE TABLE t1 ( a INT AUTO_INCREMENT PRIMARY KEY, b VARCHAR(10), UNIQUE (b) )
+ENGINE=MyISAM;
+CREATE TABLE t2 ( a INT AUTO_INCREMENT, b VARCHAR(10), INDEX (a), INDEX (b) )
+ENGINE=MERGE UNION (t1) INSERT_METHOD=FIRST;
+INSERT INTO t2 (b) VALUES (1) ON DUPLICATE KEY UPDATE b=2;
+INSERT INTO t2 (b) VALUES (1) ON DUPLICATE KEY UPDATE b=3;
+SELECT b FROM t2;
+b
+3
+DROP TABLE t1, t2;

mysql-test/t/grant_cache-master.opt

---set-variable=query_cache_size=1355776

mysql-test/t/grant_cache.test

@@ -10,6 +10,8 @@ drop table if exists test.t1,mysqltest.t1,mysqltest.t2;
 drop database if exists mysqltest;
 --enable_warnings
 
+set GLOBAL query_cache_size=1355776;
+
 reset query cache;
 flush status;
 connect (root,localhost,root,,test,$MASTER_MYPORT,$MASTER_MYSOCK);
@@ -145,3 +147,5 @@ delete from mysql.columns_priv where user in ("mysqltest_1","mysqltest_2","mysql
 flush privileges;
 drop table test.t1,mysqltest.t1,mysqltest.t2;
 drop database mysqltest;
+
+set GLOBAL query_cache_size=default;

mysql-test/t/merge.test

@@ -308,3 +308,15 @@ show index from t3;
 
 drop table t1, t2, t3;
 
+#
+# Bug#10400 - Improperly-defined MERGE table crashes with INSERT ... ON DUPLICATE KEY UPDATE
+#
+CREATE TABLE t1 ( a INT AUTO_INCREMENT PRIMARY KEY, b VARCHAR(10), UNIQUE (b) )
+  ENGINE=MyISAM;
+CREATE TABLE t2 ( a INT AUTO_INCREMENT, b VARCHAR(10), INDEX (a), INDEX (b) )
+  ENGINE=MERGE UNION (t1) INSERT_METHOD=FIRST;
+INSERT INTO t2 (b) VALUES (1) ON DUPLICATE KEY UPDATE b=2;
+INSERT INTO t2 (b) VALUES (1) ON DUPLICATE KEY UPDATE b=3;
+SELECT b FROM t2;
+DROP TABLE t1, t2;
+

sql/ha_myisammrg.h

@@ -37,7 +37,7 @@ class ha_myisammrg: public handler
   {
     return (HA_REC_NOT_IN_SEQ | HA_AUTO_PART_KEY | HA_READ_RND_SAME |
 	    HA_NULL_IN_KEY | HA_CAN_INDEX_BLOBS | HA_FILE_BASED |
-            HA_CAN_INSERT_DELAYED);
+            HA_CAN_INSERT_DELAYED | HA_ANY_INDEX_MAY_BE_UNIQUE);
   }
   ulong index_flags(uint inx, uint part, bool all_parts) const
   {

sql/handler.h

@@ -87,6 +87,7 @@
 #define HA_NO_VARCHAR	       (1 << 27)
 #define HA_CAN_BIT_FIELD       (1 << 28) /* supports bit fields */
 #define HA_NEED_READ_RANGE_BUFFER (1 << 29) /* for read_multi_range */
+#define HA_ANY_INDEX_MAY_BE_UNIQUE (1 << 30)
 
 
 /* bits in index_flags(index_number) for what you can do with index */

sql/sql_insert.cc

@@ -948,7 +948,7 @@ int write_record(THD *thd, TABLE *table,COPY_INFO *info)
 
 err:
   if (key)
-    my_afree(key);
+    my_safe_afree(key,table->max_unique_length,MAX_KEY_LENGTH);
   info->last_errno= error;
   table->file->print_error(error,MYF(0));
   DBUG_RETURN(1);

sql/table.cc

@@ -739,8 +739,13 @@ int openfrm(THD *thd, const char *name, const char *alias, uint db_stat,
       set_if_bigger(share->max_key_length,keyinfo->key_length+
                     keyinfo->key_parts);
       share->total_key_length+= keyinfo->key_length;
-      if (keyinfo->flags & HA_NOSAME)
-        set_if_bigger(share->max_unique_length, keyinfo->key_length);
+      /*
+        MERGE tables do not have unique indexes. But every key could be
+        an unique index on the underlying MyISAM table. (Bug #10400)
+      */
+      if ((keyinfo->flags & HA_NOSAME) ||
+          (ha_option & HA_ANY_INDEX_MAY_BE_UNIQUE))
+        set_if_bigger(share->max_unique_length,keyinfo->key_length);
     }
     if (primary_key < MAX_KEY &&
 	(share->keys_in_use.is_set(primary_key)))