Fixed rare bug in MYISAM introduced in 4.0.3 where the index file header was...

Fixed rare bug in MYISAM introduced in 4.0.3 where the index file header was not updated directly after an UPDATE of split dynamic rows.


myisam/mi_locking.c:
  Added DBUG info
myisam/mi_open.c:
  Added DBUG info
myisam/mi_update.c:
  More comments
  Fixed rare bug in MYISAM introduced in 4.0.3 where the index file header
  was not updated directly after an UPDATE of split dynamic rows.
mysql-test/r/myisam.result:
  Added test case for MyISAM UPDATE bug
mysql-test/t/myisam.test:
  Added test case for MyISAM UPDATE bug

myisam/mi_locking.c

@@ -76,6 +76,8 @@ int mi_lock_database(MI_INFO *info, int lock_type)
       }
       if (!count)
       {
+	DBUG_PRINT("info",("changed: %u  w_locks: %u",
+			   (uint) share->changed, share->w_locks));
 	if (share->changed && !share->w_locks)
 	{
 	  share->state.process= share->last_process=share->this_process;
@@ -352,6 +354,8 @@ int _mi_writeinfo(register MI_INFO *info, uint operation)
   int error,olderror;
   MYISAM_SHARE *share=info->s;
   DBUG_ENTER("_mi_writeinfo");
+  DBUG_PRINT("info",("operation: %u  tot_locks: %u", operation,
+		     share->tot_locks));
 
   error=0;
   if (share->tot_locks == 0)
@@ -379,9 +383,7 @@ int _mi_writeinfo(register MI_INFO *info, uint operation)
     my_errno=olderror;
   }
   else if (operation)
-  {
     share->changed= 1;			/* Mark keyfile changed */
-  }
   DBUG_RETURN(error);
 } /* _mi_writeinfo */
 

myisam/mi_open.c

@@ -730,6 +730,7 @@ uint mi_state_info_write(File file, MI_STATE_INFO *state, uint pWrite)
   uchar *ptr=buff;
   uint	i, keys= (uint) state->header.keys,
 	key_blocks=state->header.max_block_size;
+  DBUG_ENTER("mi_state_info_write");
 
   memcpy_fixed(ptr,&state->header,sizeof(state->header));
   ptr+=sizeof(state->header);
@@ -780,10 +781,10 @@ uint mi_state_info_write(File file, MI_STATE_INFO *state, uint pWrite)
   }
 
   if (pWrite & 1)
-     return my_pwrite(file,(char*) buff, (uint) (ptr-buff), 0L,
-		      MYF(MY_NABP | MY_THREADSAFE));
-  else
-    return my_write(file,  (char*) buff, (uint) (ptr-buff), MYF(MY_NABP));
+    DBUG_RETURN(my_pwrite(file,(char*) buff, (uint) (ptr-buff), 0L,
+			  MYF(MY_NABP | MY_THREADSAFE)));
+  DBUG_RETURN(my_write(file,  (char*) buff, (uint) (ptr-buff),
+		       MYF(MY_NABP)));
 }
 
 

myisam/mi_update.c

@@ -94,7 +94,14 @@ int mi_update(register MI_INFO *info, const byte *oldrec, byte *newrec)
 	if (_mi_ft_cmp(info,i,oldrec, newrec))
 	{
 	  if ((int) i == info->lastinx)
+	  {
+	  /*
+	    We are changeing the index we are reading on.  Mark that
+	    the index data has changed and we need to do a full search
+	    when doing read-next
+	  */
 	    key_changed|=HA_STATE_WRITTEN;
+	  }
 	  changed|=((ulonglong) 1 << i);
 	  if (_mi_ft_update(info,i,(char*) old_key,oldrec,newrec,pos))
 	    goto err;
@@ -121,25 +128,36 @@ int mi_update(register MI_INFO *info, const byte *oldrec, byte *newrec)
   }
   /*
     If we are running with external locking, we must update the index file
-    that something has changed
+    that something has changed.
   */
   if (changed || !my_disable_locking)
-    key_changed|= HA_STATE_KEY_CHANGED;
+    key_changed|= HA_STATE_CHANGED;
 
   if (share->calc_checksum)
   {
     info->checksum=(*share->calc_checksum)(info,newrec);
-    key_changed|= HA_STATE_KEY_CHANGED;		/* Must update index file */
+    /* Store new checksum in index file header */
+    key_changed|= HA_STATE_CHANGED;
   }
   {
-    /* Don't update index file if data file is not extended */
+    /*
+      Don't update index file if data file is not extended and no status
+      information changed
+    */
     MI_STATUS_INFO state;
+    ha_rows org_split;
+    my_off_t org_delete_link;
+
     memcpy((char*) &state, (char*) info->state, sizeof(state));
+    org_split=	     share->state.split;
+    org_delete_link= share->state.dellink;
     if ((*share->update_record)(info,pos,newrec))
       goto err;
     if (!key_changed &&
-	memcmp((char*) &state, (char*) info->state, sizeof(state)))
-      key_changed|= HA_STATE_KEY_CHANGED;	/* Must update index file */  
+	(memcmp((char*) &state, (char*) info->state, sizeof(state)) ||
+	 org_split != share->state.split ||
+	 org_delete_link != share->state.dellink))
+      key_changed|= HA_STATE_CHANGED;		/* Must update index file */
   }
   if (auto_key_changed)
     update_auto_increment(info,newrec);
@@ -163,7 +181,7 @@ int mi_update(register MI_INFO *info, const byte *oldrec, byte *newrec)
   DBUG_PRINT("error",("key: %d  errno: %d",i,my_errno));
   save_errno=my_errno;
   if (changed)
-    key_changed|= HA_STATE_KEY_CHANGED;
+    key_changed|= HA_STATE_CHANGED;
   if (my_errno == HA_ERR_FOUND_DUPP_KEY || my_errno == HA_ERR_RECORD_FILE_FULL)
   {
     info->errkey= (int) i;

mysql-test/r/myisam.result

@@ -364,3 +364,25 @@ explain select * from t1 force index (a) where a=0 or a=2;
 table	type	possible_keys	key	key_len	ref	rows	Extra
 t1	range	a	a	4	NULL	4	Using where
 drop table t1,t2;
+create table t1 (a int not null auto_increment primary key, b varchar(255));
+insert into t1 (b) values (repeat('a',100)),(repeat('b',100)),(repeat('c',100));
+update t1 set b=repeat(left(b,1),200) where a=1;
+delete from t1 where (a & 1)= 0;
+update t1 set b=repeat('e',200) where a=1;
+flush tables;
+check table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+update t1 set b=repeat(left(b,1),255) where a between 1 and 5;
+update t1 set b=repeat(left(b,1),10) where a between 32 and 43;
+update t1 set b=repeat(left(b,1),2) where a between 64 and 66;
+update t1 set b=repeat(left(b,1),65) where a between 67 and 70;
+check table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+insert into t1 (b) values (repeat('z',100));
+update t1 set b="test" where left(b,1) > 'n';
+check table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+drop table t1;

mysql-test/t/myisam.test

@@ -352,3 +352,37 @@ explain select * from t1,t2 force index(c) where t1.a=t2.a;
 explain select * from t1 where a=0 or a=2;
 explain select * from t1 force index (a) where a=0 or a=2;
 drop table t1,t2;
+
+#
+# Test bug when updating a split dynamic row where keys are not changed
+#
+
+create table t1 (a int not null auto_increment primary key, b varchar(255));
+insert into t1 (b) values (repeat('a',100)),(repeat('b',100)),(repeat('c',100));
+update t1 set b=repeat(left(b,1),200) where a=1;
+delete from t1 where (a & 1)= 0;
+update t1 set b=repeat('e',200) where a=1;
+flush tables;
+check table t1;
+
+#
+# check updating with keys
+#
+
+disable_query_log;
+let $1 = 100;
+while ($1)
+{
+  eval insert into t1 (b) values (repeat(char(($1 & 32)+65), $1));
+  dec $1;
+}
+enable_query_log;
+update t1 set b=repeat(left(b,1),255) where a between 1 and 5;
+update t1 set b=repeat(left(b,1),10) where a between 32 and 43;
+update t1 set b=repeat(left(b,1),2) where a between 64 and 66;
+update t1 set b=repeat(left(b,1),65) where a between 67 and 70;
+check table t1;
+insert into t1 (b) values (repeat('z',100));
+update t1 set b="test" where left(b,1) > 'n';
+check table t1;
+drop table t1;