Fixed bug in multi-table-delete code

client/mysqltest.c:
  Added --big-test argument
libmysqld/lib_sql.cc:
  Reset error messages before new query.
libmysqld/lib_vio.c:
  Fixed reading of results.
mysql-test/mysql-test-run.sh:
  Added option --big
mysql-test/r/multi_update.result:
  More multi-delete tests
mysql-test/t/bdb-crash.test:
  Added missing test if BDB is supported
mysql-test/t/multi_update.test:
  More multi-delete tests

client/mysqltest.c

@@ -43,7 +43,7 @@
 
 **********************************************************************/
 
-#define MTEST_VERSION "1.9"
+#define MTEST_VERSION "1.10"
 
 #include <global.h>
 #include <my_sys.h>
@@ -84,7 +84,7 @@
 static int record = 0, verbose = 0, silent = 0, opt_sleep=0;
 static char *db = 0, *pass=0;
 const char* user = 0, *host = 0, *unix_sock = 0;
-static int port = 0;
+static int port = 0, opt_big_test=0;
 static uint start_lineno, *lineno;
 
 static char **default_argv;
@@ -1410,6 +1410,7 @@ struct option long_options[] =
 {
   {"debug",       optional_argument, 0, '#'},
   {"database",    required_argument, 0, 'D'},
+  {"big-test",	  no_argument,	     0, 'B'},
   {"help",        no_argument,       0, '?'},
   {"host",        required_argument, 0, 'h'},
   {"password",    optional_argument, 0, 'p'},
@@ -1453,6 +1454,7 @@ void usage()
   -u, --user=...           User for login.\n\
   -p[password], --password[=...]\n\
                            Password to use when connecting to server.\n\
+  -B, --big-test	   Define BIG_TEST to 1\n\
   -D, --database=...       Database to use.\n\
   -P, --port=...           Port number to use for connection.\n\
   -S, --socket=...         Socket file to use for connection.\n\
@@ -1475,7 +1477,7 @@ int parse_args(int argc, char **argv)
   load_defaults("my",load_default_groups,&argc,&argv);
   default_argv= argv;
 
-  while((c = getopt_long(argc, argv, "h:p::u:P:D:S:R:x:t:T:#:?rvVq",
+  while((c = getopt_long(argc, argv, "h:p::u:BP:D:S:R:x:t:T:#:?rvVq",
 			 long_options, &option_index)) != EOF)
     {
       switch(c)	{
@@ -1508,6 +1510,9 @@ int parse_args(int argc, char **argv)
 	else
 	  tty_password=1;
 	break;
+      case 'B':
+        opt_big_test=1;
+        break;
       case 'P':
 	port = atoi(optarg);
 	break;
@@ -1814,6 +1819,7 @@ static void var_from_env(const char* name, const char* def_val)
   hash_insert(&var_hash, (byte*)v);
 }
 
+
 static void init_var_hash()
 {
   if (hash_init(&var_hash, 1024, 0, 0, get_var_key, var_free, MYF(0)))
@@ -1821,6 +1827,7 @@ static void init_var_hash()
   var_from_env("MASTER_MYPORT", "9306");
   var_from_env("SLAVE_MYPORT", "9307");
   var_from_env("MYSQL_TEST_DIR", "/tmp");
+  var_from_env("BIG_TEST", opt_big_test ? "1" : "0");
 }
 
 int main(int argc, char** argv)

libmysqld/lib_sql.cc

@@ -74,6 +74,9 @@ bool lib_dispatch_command(enum enum_server_command command, NET *net,
 {
   THD *thd=(THD *) net->vio->dest_thd;
   thd->store_globals();				// Fix if more than one connect
+  thd->net.last_error[0]=0;			// Clear error message
+  thd->net.last_errno=0;
+  
   net_new_transaction(&thd->net);
   return dispatch_command(command, thd, (char *) arg, length + 1);
 }

libmysqld/lib_vio.c

@@ -139,6 +139,8 @@ int vio_read(Vio * vio, gptr buf, int size)
       			 uint4korr(vio->packets + sizeof(char *));
     vio->packets = *(char **)vio->packets;
   }
+  if (vio->where_in_packet + size > vio->end_of_packet)
+    size = vio->end_of_packet - vio->where_in_packet;
   memcpy(buf, vio->where_in_packet, size);
   vio->where_in_packet += size;
   return (size);

mysql-test/mysql-test-run.sh

@@ -151,6 +151,8 @@ while test $# -gt 0; do
       DO_BENCH=1
       NO_SLAVE=1
       ;;  
+    --big*)			# Actually --big-test
+      EXTRA_MYSQL_TEST_OPT="$EXTRA_MYSQL_TEST_OPT $1" ;;
     --sleep=*)
       EXTRA_MYSQL_TEST_OPT="$EXTRA_MYSQL_TEST_OPT $1"
       SLEEP_TIME=`$ECHO "$1" | $SED -e "s;--sleep=;;"`

mysql-test/r/multi_update.result

-id1	t
-1	3
-2	2
-id2	t
-1	3
-1	2
-1	1
-id3	t
-2	3
-2	2
-2	1
-1	3
-1	2
-1	1
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+test.t2	check	status	OK
+test.t3	check	status	OK
+count(*)
+0
+count(*)
+0
+count(*)
+0
+count(*)
+0
+count(*)
+0
+count(*)
+0
+count(*)
+0
+count(*)
+0
+count(*)
+0

mysql-test/t/bdb-crash.test

+-- source include/have_bdb.inc
 # test for bug reported by Mark Steele
 
 drop table if exists tblChange;

mysql-test/t/multi_update.test

+#
+# Only run the test if we are using --big-test, because this test takes a
+# long time
+#
+-- require r/big_test.require
+eval select $BIG_TEST as using_big_test;
+
 drop table if exists t1,t2,t3;
 create table t1(id1 int not null auto_increment primary key, t char(12));
 create table t2(id2 int not null, t char(12), index(id2));
@@ -25,11 +32,20 @@ delete t1.*, t2.*, t3.*  from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3
 
 check table t1, t2, t3;
 
-select * from t1 where id1 > 9500;
-select * from t2 where id2 > 9500;
-select * from t3 where id3 > 9500;
+select count(*) from t1 where id1 > 9500;
+select count(*) from t2 where id2 > 9500;
+select count(*) from t3 where id3 > 9500;
 
 delete t1, t2, t3  from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 500;
-select * from t1 where id1 > 500;
-select * from t2 where id2 > 500;
-select * from t3 where id3 > 500;
+select count(*) from t1 where id1 > 500;
+select count(*) from t2 where id2 > 500;
+select count(*) from t3 where id3 > 500;
+
+delete t1, t2, t3  from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 0;
+
+# These queries will force a scan of the table
+select count(*) from t1 where id1;
+select count(*) from t2 where id2;
+select count(*) from t3 where id3;
+
+drop table t1,t2,t3;

sql/filesort.cc

@@ -674,7 +674,7 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
   int error;
   uint sort_length,offset;
   ulong maxcount;
-  ha_rows count,max_rows;
+  ha_rows max_rows,org_max_rows;
   my_off_t to_start_filepos;
   uchar *strpos;
   BUFFPEK *buffpek,**refpek;
@@ -685,12 +685,12 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
 
   statistic_increment(filesort_merge_passes, &LOCK_status);
 
-  count=error=0;
+  error=0;
   offset=(sort_length=param->sort_length)-param->ref_length;
   maxcount=(ulong) (param->keys/((uint) (Tb-Fb) +1));
   to_start_filepos=my_b_tell(to_file);
   strpos=(uchar*) sort_buffer;
-  max_rows=param->max_rows;
+  org_max_rows=max_rows=param->max_rows;
 
   if (init_queue(&queue,(uint) (Tb-Fb)+1,offsetof(BUFFPEK,key),0,
 		 (int (*) (void *, byte *,byte*))
@@ -698,7 +698,6 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
     DBUG_RETURN(1);				/* purecov: inspected */
   for (buffpek= Fb ; buffpek <= Tb ; buffpek++)
   {
-    count+= buffpek->count;
     buffpek->base= strpos;
     buffpek->max_keys=maxcount;
     strpos+= (uint) (error=(int) read_to_buffer(from_file,buffpek,
@@ -725,6 +724,8 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
       error=1; goto err;			/* purecov: inspected */
     }
     buffpek->key+=sort_length;
+    buffpek->mem_count--;
+    max_rows--;
     queue_replaced(&queue);			// Top element has been used
   }
   else
@@ -741,7 +742,8 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
       buffpek=(BUFFPEK*) queue_top(&queue);
       if (cmp)					// Remove duplicates
       {
-	if (!cmp(&sort_length, &(param->unique_buff), (uchar**) &buffpek->key))
+	if (!(*cmp)(&sort_length, &(param->unique_buff),
+		    (uchar**) &buffpek->key))
 	  goto skip_duplicate;
 	memcpy(param->unique_buff, (uchar*) buffpek->key,sort_length);
       }
@@ -803,6 +805,20 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
   buffpek=(BUFFPEK*) queue_top(&queue);
   buffpek->base= sort_buffer;
   buffpek->max_keys=param->keys;
+
+  /*
+    As we know all entries in the buffer are unique, we only have to
+    check if the first one is the same as the last one we wrote
+  */
+  if (cmp)
+  {
+    if (!(*cmp)(&sort_length, &(param->unique_buff), (uchar**) &buffpek->key))
+    {
+      buffpek->key+=sort_length;	// Remove duplicate
+      --buffpek->mem_count;
+    }
+  }
+
   do
   {
     if ((ha_rows) buffpek->mem_count > max_rows)
@@ -810,6 +826,7 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
       buffpek->mem_count=(uint) max_rows;
       buffpek->count=0;			/* Don't read more */
     }
+    max_rows-=buffpek->mem_count;
     if (flag == 0)
     {
       if (my_b_write(to_file,(byte*) buffpek->key,
@@ -834,7 +851,7 @@ int merge_buffers(SORTPARAM *param, IO_CACHE *from_file,
 	 != -1 && error != 0);
 
 end:
-  lastbuff->count=min(count,param->max_rows);
+  lastbuff->count=min(org_max_rows-max_rows,param->max_rows);
   lastbuff->file_pos=to_start_filepos;
 err:
   delete_queue(&queue);