Bug#35111 - Truncate a MyISAM partitioned table does not reset

the auto_increment value
      
This is an alternative patch that instead of allowing RECREATE TABLE
on TRUNCATE TABLE it implements reset_auto_increment that is called
after delete_all_rows.

Note: this bug was fixed by Mattias Jonsson:
Pusing this patch: http://lists.mysql.com/commits/70370

mysql-test/suite/parts/r/partition_auto_increment_memory.result

@@ -381,12 +381,12 @@ Table	Create Table
 t1	CREATE TABLE `t1` (
   `c1` int(11) NOT NULL AUTO_INCREMENT,
   PRIMARY KEY (`c1`)
-) ENGINE=MEMORY AUTO_INCREMENT=28 DEFAULT CHARSET=latin1
+) ENGINE=MEMORY AUTO_INCREMENT=2 DEFAULT CHARSET=latin1
 /*!50100 PARTITION BY HASH (c1)
 PARTITIONS 2 */
 SELECT * FROM t1 ORDER BY c1;
 c1
-27
+1
 INSERT INTO t1 VALUES (100);
 INSERT INTO t1 VALUES (NULL);
 DELETE FROM t1 WHERE c1 >= 100;

mysql-test/suite/parts/r/partition_auto_increment_myisam.result

@@ -381,12 +381,12 @@ Table	Create Table
 t1	CREATE TABLE `t1` (
   `c1` int(11) NOT NULL AUTO_INCREMENT,
   PRIMARY KEY (`c1`)
-) ENGINE=MyISAM AUTO_INCREMENT=28 DEFAULT CHARSET=latin1
+) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=latin1
 /*!50100 PARTITION BY HASH (c1)
 PARTITIONS 2 */
 SELECT * FROM t1 ORDER BY c1;
 c1
-27
+1
 INSERT INTO t1 VALUES (100);
 INSERT INTO t1 VALUES (NULL);
 DELETE FROM t1 WHERE c1 >= 100;

sql/ha_partition.cc

@@ -3179,6 +3179,7 @@ int ha_partition::delete_row(const uchar *buf)
 int ha_partition::delete_all_rows()
 {
   int error;
+  bool truncate= FALSE;
   handler **file;
   THD *thd= ha_thd();
   DBUG_ENTER("ha_partition::delete_all_rows");
@@ -3190,12 +3191,16 @@ int ha_partition::delete_all_rows()
     ha_data->next_auto_inc_val= 0;
     ha_data->auto_inc_initialized= FALSE;
     unlock_auto_increment();
+    truncate= TRUE;
   }
   file= m_file;
   do
   {
     if ((error= (*file)->ha_delete_all_rows()))
       DBUG_RETURN(error);
+    /* Ignore the error */
+    if (truncate)
+      (void) (*file)->ha_reset_auto_increment(0);
   } while (*(++file));
   DBUG_RETURN(0);
 }

storage/heap/ha_heap.cc

@@ -419,6 +419,14 @@ int ha_heap::delete_all_rows()
   return 0;
 }
 
+
+int ha_heap::reset_auto_increment(ulonglong value)
+{
+  file->s->auto_increment= value;
+  return 0;
+}
+
+
 int ha_heap::external_lock(THD *thd, int lock_type)
 {
   return 0;					// No external locking

storage/heap/ha_heap.h

@@ -98,6 +98,7 @@ public:
   int reset();
   int external_lock(THD *thd, int lock_type);
   int delete_all_rows(void);
+  int reset_auto_increment(ulonglong value);
   int disable_indexes(uint mode);
   int enable_indexes(uint mode);
   int indexes_are_disabled(void);

storage/myisam/ha_myisam.cc

@@ -1870,6 +1870,12 @@ int ha_myisam::delete_all_rows()
   return mi_delete_all_rows(file);
 }
 
+int ha_myisam::reset_auto_increment(ulonglong value)
+{
+  file->s->state.auto_increment= value;
+  return 0;
+}
+
 int ha_myisam::delete_table(const char *name)
 {
   return mi_delete_table(name);

storage/myisam/ha_myisam.h

@@ -101,6 +101,7 @@ class ha_myisam: public handler
   int reset(void);
   int external_lock(THD *thd, int lock_type);
   int delete_all_rows(void);
+  int reset_auto_increment(ulonglong value);
   int disable_indexes(uint mode);
   int enable_indexes(uint mode);
   int indexes_are_disabled(void);