Fixed lp:970528 "Server crashes in my_strnncollsp_simple on LEFT JOIN with CSV table, TEXT field"

The main problem was a bug in CSV where it provided wrong statistics (it claimed the table was empty when it wasn't)
I also fixed wrong freeing of blob's in the CSV handler. (Any call to handler::read_first_row() on a CSV table with blobs would fail)



mysql-test/r/csv.result:
  Added new test case
mysql-test/r/partition_innodb.result:
  Updated test results after fixing bug with impossible partitions and const tables
mysql-test/t/csv.test:
  Added new test case
sql/sql_select.cc:
  Cleaned up code for handling of partitions.
  Fixed also a bug where we didn't threat a table with impossible partitions as a const table.
storage/csv/ha_tina.cc:
  Allocate blobroot onces.

mysql-test/r/csv.result

@@ -5415,4 +5415,17 @@ foo
 
 
 DROP TABLE t1;
+CREATE TABLE t1 ( b TEXT NOT NULL ) ENGINE=MYISAM;
+INSERT INTO t1 VALUES ('x'),('y');
+CREATE TABLE t2 ( a VARCHAR(1) NOT NULL ) ENGINE=CSV;
+INSERT INTO t2 VALUES ('r'),('t');
+SELECT * FROM t2 ORDER BY a;
+a
+r
+t
+SELECT * FROM t1 LEFT JOIN t2 ON ( b = a );
+b	a
+x	NULL
+y	NULL
+drop table t1,t2;
 End of 5.1 tests

mysql-test/r/partition_innodb.result

@@ -48,13 +48,13 @@ insert INTO t1 VALUES (110);
 ERROR HY000: Table has no partition for value 110
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a > 90;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1		ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a >= 90;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1		ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a = 90;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1		ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a = 89;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	p90	ALL	NULL	NULL	NULL	NULL	3	Using where
@@ -63,16 +63,16 @@ id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	p90	ALL	NULL	NULL	NULL	NULL	3	Using where
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a > 89;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1		ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a = 100;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1		ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a >= 100;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1		ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a > 100;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1		ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 DROP TABLE t1;
 #
 # Bug#50104: Partitioned table with just 1 partion works with fk

mysql-test/t/csv.test

@@ -1820,5 +1820,20 @@ INSERT INTO t1 VALUES(-1);
 SELECT * FROM t1;
 DROP TABLE t1;
 
+#
+# Bug#970528 
+# Server crashes in my_strnncollsp_simple on LEFT JOIN with CSV table,
+# TEXT field
+#
+
+CREATE TABLE t1 ( b TEXT NOT NULL ) ENGINE=MYISAM;
+INSERT INTO t1 VALUES ('x'),('y');
+
+CREATE TABLE t2 ( a VARCHAR(1) NOT NULL ) ENGINE=CSV;
+INSERT INTO t2 VALUES ('r'),('t');
+
+SELECT * FROM t2 ORDER BY a;
+SELECT * FROM t1 LEFT JOIN t2 ON ( b = a );
+drop table t1,t2;
 
 --echo End of 5.1 tests

sql/sql_select.cc

@@ -2691,6 +2691,11 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables_arg, COND *conds,
     table_vector[i]=s->table=table=tables->table;
     table->pos_in_table_list= tables;
     error= table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
+#ifdef WITH_PARTITION_STORAGE_ENGINE
+    const bool no_partitions_used= table->no_partitions_used;
+#else
+    const bool no_partitions_used= FALSE;
+#endif
 
     DBUG_EXECUTE_IF("bug11747970_raise_error",
                     {
@@ -2724,11 +2729,9 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables_arg, COND *conds,
     if (*s->on_expr_ref)
     {
       /* s is the only inner table of an outer join */
-#ifdef WITH_PARTITION_STORAGE_ENGINE
-      if ((!table->file->stats.records || table->no_partitions_used) && !embedding)
-#else
-      if (!table->file->stats.records && !embedding)
-#endif
+      if (((!table->file->stats.records &&
+            (table->file->ha_table_flags() & HA_STATS_RECORDS_IS_EXACT)) ||
+           no_partitions_used) && !embedding)
       {						// Empty table
         s->dependent= 0;                        // Ignore LEFT JOIN depend.
         no_rows_const_tables |= table->map;
@@ -2756,15 +2759,11 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables_arg, COND *conds,
       while (embedding);
       continue;
     }
-#ifdef WITH_PARTITION_STORAGE_ENGINE
-    const bool no_partitions_used= table->no_partitions_used;
-#else
-    const bool no_partitions_used= FALSE;
-#endif
-    if ((table->s->system || table->file->stats.records <= 1 ||
+    if ((table->s->system ||
+         (table->file->stats.records <= 1 &&
+          (table->file->ha_table_flags() & HA_STATS_RECORDS_IS_EXACT)) ||
          no_partitions_used) &&
 	!s->dependent &&
-	(table->file->ha_table_flags() & HA_STATS_RECORDS_IS_EXACT) &&
         !table->fulltext_searched && !join->no_const_tables)
     {
       set_position(join,const_count++,s,(KEYUSE*) 0);

storage/csv/ha_tina.cc

@@ -854,6 +854,7 @@ int ha_tina::open(const char *name, int mode, uint open_options)
   */
   thr_lock_data_init(&share->lock, &lock, (void*) this);
   ref_length= sizeof(my_off_t);
+  init_alloc_root(&blobroot, BLOB_MEMROOT_ALLOC_SIZE, 0);
 
   share->lock.get_status= tina_get_status;
   share->lock.update_status= tina_update_status;
@@ -871,6 +872,7 @@ int ha_tina::close(void)
 {
   int rc= 0;
   DBUG_ENTER("ha_tina::close");
+  free_root(&blobroot, MYF(0));
   rc= my_close(data_file, MYF(0));
   DBUG_RETURN(free_share(share) || rc);
 }
@@ -1086,11 +1088,9 @@ int ha_tina::rnd_init(bool scan)
 
   current_position= next_position= 0;
   stats.records= 0;
-  records_is_known= 0;
+  records_is_known= found_end_of_file= 0;
   chain_ptr= chain;
 
-  init_alloc_root(&blobroot, BLOB_MEMROOT_ALLOC_SIZE, 0);
-
   DBUG_RETURN(0);
 }
 
@@ -1122,10 +1122,16 @@ int ha_tina::rnd_next(uchar *buf)
 
   /* don't scan an empty file */
   if (!local_saved_data_file_length)
+  {
+    found_end_of_file= 1;
     DBUG_RETURN(HA_ERR_END_OF_FILE);
-
+  }
   if ((rc= find_current_row(buf)))
+  {
+    DBUG_PRINT("warning", ("got error %d while reading file", rc));
+    found_end_of_file= (rc == HA_ERR_END_OF_FILE);
     DBUG_RETURN(rc);
+  }
 
   stats.records++;
   DBUG_RETURN(0);
@@ -1220,8 +1226,7 @@ int ha_tina::rnd_end()
   my_off_t file_buffer_start= 0;
   DBUG_ENTER("ha_tina::rnd_end");
 
-  free_root(&blobroot, MYF(0));
-  records_is_known= 1;
+  records_is_known= found_end_of_file;
 
   if ((chain_ptr - chain)  > 0)
   {
@@ -1394,8 +1399,6 @@ int ha_tina::repair(THD* thd, HA_CHECK_OPT* check_opt)
   /* set current position to the beginning of the file */
   current_position= next_position= 0;
 
-  init_alloc_root(&blobroot, BLOB_MEMROOT_ALLOC_SIZE, 0);
-
   /* Read the file row-by-row. If everything is ok, repair is not needed. */
   while (!(rc= find_current_row(buf)))
   {
@@ -1603,8 +1606,6 @@ int ha_tina::check(THD* thd, HA_CHECK_OPT* check_opt)
   /* set current position to the beginning of the file */
   current_position= next_position= 0;
 
-  init_alloc_root(&blobroot, BLOB_MEMROOT_ALLOC_SIZE, 0);
-
   /* Read the file row-by-row. If everything is ok, repair is not needed. */
   while (!(rc= find_current_row(buf)))
   {
@@ -1628,6 +1629,13 @@ int ha_tina::check(THD* thd, HA_CHECK_OPT* check_opt)
 }
 
 
+int ha_tina::reset(void)
+{
+  free_root(&blobroot, MYF(0));
+  return 0;
+}
+
+
 bool ha_tina::check_if_incompatible_data(HA_CREATE_INFO *info,
 					   uint table_changes)
 {

storage/csv/ha_tina.h

@@ -84,7 +84,7 @@ class ha_tina: public handler
   uchar chain_alloced;
   uint32 chain_size;
   uint local_data_file_version;  /* Saved version of the data file used */
-  bool records_is_known;
+  bool records_is_known, found_end_of_file;
   MEM_ROOT blobroot;
 
 private:
@@ -156,6 +156,7 @@ class ha_tina: public handler
   bool auto_repair() const { return 1; }
   void position(const uchar *record);
   int info(uint);
+  int reset();
   int extra(enum ha_extra_function operation);
   int delete_all_rows(void);
   int create(const char *name, TABLE *form, HA_CREATE_INFO *create_info);