BUG#47073 - valgrind errs, corruption,failed repair of partition,

            low myisam_sort_buffer_size

Repair by sort (default) or parallel repair of a MyISAM table
(doesn't matter partitioned or not) as well as bulk inserts
and enable indexes some times didn't failover to repair with
key cache.

The problem was that after unsuccessful attempt, data file was
closed. Whereas repair with key cache requires open data file.
Fixed by reopening data file.

Also fixed a valgrind warning, which may appear during repair
by sort or parallel repair with certain myisam_sort_buffer_size
number of rows and length of an index entry (very dependent).

mysql-test/r/myisam.result

@@ -2271,4 +2271,32 @@ checksum table t3;
 Table	Checksum
 test.t3	326284887
 drop table t1,t2,t3;
+CREATE TABLE t1(a INT, b CHAR(10), KEY(a), KEY(b));
+INSERT INTO t1 VALUES(1,'0'),(2,'0'),(3,'0'),(4,'0'),(5,'0'),
+(6,'0'),(7,'0');
+INSERT INTO t1 SELECT a+10,b FROM t1;
+INSERT INTO t1 SELECT a+20,b FROM t1;
+INSERT INTO t1 SELECT a+40,b FROM t1;
+INSERT INTO t1 SELECT a+80,b FROM t1;
+INSERT INTO t1 SELECT a+160,b FROM t1;
+INSERT INTO t1 SELECT a+320,b FROM t1;
+INSERT INTO t1 SELECT a+640,b FROM t1;
+INSERT INTO t1 SELECT a+1280,b FROM t1;
+INSERT INTO t1 SELECT a+2560,b FROM t1;
+INSERT INTO t1 SELECT a+5120,b FROM t1;
+SET myisam_sort_buffer_size=4;
+REPAIR TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	repair	error	myisam_sort_buffer_size is too small
+test.t1	repair	warning	Number of rows changed from 0 to 7168
+test.t1	repair	status	OK
+SET myisam_repair_threads=2;
+REPAIR TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	repair	error	myisam_sort_buffer_size is too small
+test.t1	repair	warning	Number of rows changed from # to 7168
+test.t1	repair	status	OK
+SET myisam_repair_threads=@@global.myisam_repair_threads;
+SET myisam_sort_buffer_size=@@global.myisam_sort_buffer_size;
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/myisam.test

@@ -1518,5 +1518,33 @@ CREATE TABLE t3 select * from t1;
 checksum table t3;
 drop table t1,t2,t3;
 
+
+#
+# BUG#47073 - valgrind errs, corruption,failed repair of partition,
+#             low myisam_sort_buffer_size
+#
+CREATE TABLE t1(a INT, b CHAR(10), KEY(a), KEY(b));
+INSERT INTO t1 VALUES(1,'0'),(2,'0'),(3,'0'),(4,'0'),(5,'0'),
+                     (6,'0'),(7,'0');
+INSERT INTO t1 SELECT a+10,b FROM t1;
+INSERT INTO t1 SELECT a+20,b FROM t1;
+INSERT INTO t1 SELECT a+40,b FROM t1;
+INSERT INTO t1 SELECT a+80,b FROM t1;
+INSERT INTO t1 SELECT a+160,b FROM t1;
+INSERT INTO t1 SELECT a+320,b FROM t1;
+INSERT INTO t1 SELECT a+640,b FROM t1;
+INSERT INTO t1 SELECT a+1280,b FROM t1;
+INSERT INTO t1 SELECT a+2560,b FROM t1;
+INSERT INTO t1 SELECT a+5120,b FROM t1;
+SET myisam_sort_buffer_size=4;
+REPAIR TABLE t1;
+SET myisam_repair_threads=2;
+# May report different values depending on threads activity.
+--replace_regex /changed from [0-9]+/changed from #/
+REPAIR TABLE t1;
+SET myisam_repair_threads=@@global.myisam_repair_threads;
+SET myisam_sort_buffer_size=@@global.myisam_sort_buffer_size;
+DROP TABLE t1;
+
 --echo End of 5.1 tests
 

storage/myisam/ha_myisam.cc

@@ -1087,22 +1087,6 @@ int ha_myisam::repair(THD *thd, MI_CHECK &param, bool do_optimize)
   ha_rows rows= file->state->records;
   DBUG_ENTER("ha_myisam::repair");
 
-  /*
-    Normally this method is entered with a properly opened table. If the
-    repair fails, it can be repeated with more elaborate options. Under
-    special circumstances it can happen that a repair fails so that it
-    closed the data file and cannot re-open it. In this case file->dfile
-    is set to -1. We must not try another repair without an open data
-    file. (Bug #25289)
-  */
-  if (file->dfile == -1)
-  {
-    sql_print_information("Retrying repair of: '%s' failed. "
-                          "Please try REPAIR EXTENDED or myisamchk",
-                          table->s->path.str);
-    DBUG_RETURN(HA_ADMIN_FAILED);
-  }
-
   param.db_name=    table->s->db.str;
   param.table_name= table->alias;
   param.tmpfile_createflag = O_RDWR | O_TRUNC;

storage/myisam/mi_check.c

@@ -2561,8 +2561,9 @@ err:
       VOID(my_close(new_file,MYF(0)));
       VOID(my_raid_delete(param->temp_filename,share->base.raid_chunks,
 			  MYF(MY_WME)));
-      if (info->dfile == new_file)
-	info->dfile= -1;
+      if (info->dfile == new_file) /* Retry with key cache */
+        if (unlikely(mi_open_datafile(info, share, name, -1)))
+          param->retry_repair= 0; /* Safety */
     }
     mi_mark_crashed_on_repair(info);
   }
@@ -3095,8 +3096,9 @@ err:
       VOID(my_close(new_file,MYF(0)));
       VOID(my_raid_delete(param->temp_filename,share->base.raid_chunks,
 			  MYF(MY_WME)));
-      if (info->dfile == new_file)
-	info->dfile= -1;
+      if (info->dfile == new_file) /* Retry with key cache */
+        if (unlikely(mi_open_datafile(info, share, name, -1)))
+          param->retry_repair= 0; /* Safety */
     }
     mi_mark_crashed_on_repair(info);
   }

storage/myisam/sort.c

@@ -788,7 +788,11 @@ static int NEAR_F merge_many_buff(MI_SORT_PARAM *info, uint keys,
 cleanup:
   close_cached_file(to_file);                   /* This holds old result */
   if (to_file == t_file)
+  {
     *t_file=t_file2;                            /* Copy result file */
+    t_file->current_pos= &t_file->write_pos;
+    t_file->current_end= &t_file->write_end;
+  }
 
   DBUG_RETURN(*maxbuffer >= MERGEBUFF2);        /* Return 1 if interrupted */
 } /* merge_many_buff */