Bug#14400 - Query joins wrong rows from table which is subject of

            "concurrent insert"
Additional fix for full keys and test case.

myisam/mi_rkey.c

@@ -78,24 +78,18 @@ int mi_rkey(MI_INFO *info, byte *buf, int inx, const byte *key, uint key_len,
   if (!_mi_search(info,keyinfo, key_buff, use_key_length,
 		  myisam_read_vec[search_flag], info->s->state.key_root[inx]))
   {
-    if (info->lastpos >= info->state->data_file_length)
+    /*
+      If we searching for a partial key (or using >, >=, < or <=) and
+      the data is outside of the data file, we need to continue searching
+      for the first key inside the data file
+    */
+    if (info->lastpos >= info->state->data_file_length &&
+        (search_flag != HA_READ_KEY_EXACT ||
+         last_used_keyseg != keyinfo->seg + keyinfo->keysegs))
     {
       do
       {
         uint not_used;
-        /*
-          If we are searching for an exact key, abort if we find a bigger
-          key.
-        */
-        if (search_flag == HA_READ_KEY_EXACT &&
-            (use_key_length == USE_WHOLE_KEY ||
-             _mi_key_cmp(keyinfo->seg, key_buff, info->lastkey, use_key_length,
-                         SEARCH_FIND, &not_used)))
-        {
-          my_errno= HA_ERR_END_OF_FILE;
-          info->lastpos= HA_OFFSET_ERROR;
-          break;
-        }
         /*
           Skip rows that are inserted by other threads since we got a lock
           Note that this can only happen if we are not searching after an
@@ -107,8 +101,20 @@ int mi_rkey(MI_INFO *info, byte *buf, int inx, const byte *key, uint key_len,
                              myisam_readnext_vec[search_flag],
                              info->s->state.key_root[inx]))
           break;
+        /*
+          Check that the found key does still match the search.
+          _mi_search_next() delivers the next key regardless of its
+          value.
+        */
+        if (search_flag == HA_READ_KEY_EXACT &&
+            _mi_key_cmp(keyinfo->seg, key_buff, info->lastkey, use_key_length,
+                        SEARCH_FIND, &not_used))
+        {
+          my_errno= HA_ERR_KEY_NOT_FOUND;
+          info->lastpos= HA_OFFSET_ERROR;
+          break;
         }
-      while (info->lastpos >= info->state->data_file_length);
+      } while (info->lastpos >= info->state->data_file_length);
     }
   }
   if (share->concurrent_insert)

mysql-test/r/myisam.result

@@ -487,3 +487,16 @@ a	a	b
 1	1	1
 2	2	1
 drop table t1,t2;
+CREATE TABLE t1 (c1 varchar(250) NOT NULL);
+CREATE TABLE t2 (c1 varchar(250) NOT NULL, PRIMARY KEY (c1));
+INSERT INTO t1 VALUES ('test000001'), ('test000002'), ('test000003');
+INSERT INTO t2 VALUES ('test000002'), ('test000003'), ('test000004');
+LOCK TABLES t1 READ LOCAL, t2 READ LOCAL;
+SELECT t1.c1 AS t1c1, t2.c1 AS t2c1 FROM t1, t2
+WHERE t1.c1 = t2.c1 HAVING t1c1 != t2c1;
+t1c1	t2c1
+INSERT INTO t2 VALUES ('test000001'), ('test000005');
+SELECT t1.c1 AS t1c1, t2.c1 AS t2c1 FROM t1, t2
+WHERE t1.c1 = t2.c1 HAVING t1c1 != t2c1;
+t1c1	t2c1
+DROP TABLE t1,t2;

mysql-test/t/myisam.test

@@ -461,6 +461,7 @@ drop table t1;
 #
 # Bug #14400  Join could miss concurrently inserted row
 #
+# Partial key.
 create table t1 (a int not null, primary key(a));
 create table t2 (a int not null, b int not null, primary key(a,b));
 insert into t1 values (1),(2),(3),(4),(5),(6);
@@ -473,5 +474,22 @@ disconnect root;
 connection default;
 select straight_join * from t1,t2 force index (primary) where t1.a=t2.a;
 drop table t1,t2;
+#
+# Full key.
+CREATE TABLE t1 (c1 varchar(250) NOT NULL);
+CREATE TABLE t2 (c1 varchar(250) NOT NULL, PRIMARY KEY (c1));
+INSERT INTO t1 VALUES ('test000001'), ('test000002'), ('test000003');
+INSERT INTO t2 VALUES ('test000002'), ('test000003'), ('test000004');
+LOCK TABLES t1 READ LOCAL, t2 READ LOCAL;
+SELECT t1.c1 AS t1c1, t2.c1 AS t2c1 FROM t1, t2
+  WHERE t1.c1 = t2.c1 HAVING t1c1 != t2c1;
+connect (con1,localhost,root,,);
+connection con1;
+INSERT INTO t2 VALUES ('test000001'), ('test000005');
+disconnect con1;
+connection default;
+SELECT t1.c1 AS t1c1, t2.c1 AS t2c1 FROM t1, t2
+  WHERE t1.c1 = t2.c1 HAVING t1c1 != t2c1;
+DROP TABLE t1,t2;
 
 # end of 4.0 tests