BUG#18962: DROP PARTITION fails when partitions dropped for subpartitions with...

BUG#18962: DROP PARTITION fails when partitions dropped for subpartitions with default naming procedure
Fixed naming procedures for default partitioning and default subpartitioning

mysql-test/r/partition_pruning.result

@@ -596,7 +596,7 @@ f_int1
 NULL
 explain partitions select * from t1 where f_int1 is null;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	part4_p2sp0	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t1	part4_part4sp0	system	NULL	NULL	NULL	NULL	1	
 drop table t1;
 create table t1 (a int not null, b int not null)
 partition by list(a) 
@@ -625,16 +625,16 @@ insert into t1 values (1,1),(1,2),(1,3),(1,4),
 (2,1),(2,2),(2,3),(2,4), (NULL,1);
 explain partitions select * from t1 where a IS NULL AND (b=1 OR b=2);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	pn_p3sp0,pn_p3sp1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t1	pn_pnsp0,pn_pnsp1	system	NULL	NULL	NULL	NULL	1	
 explain partitions select * from t1 where (a IS NULL or a < 1) AND (b=1 OR b=2);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	pn_p3sp0,pn_p3sp1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t1	pn_pnsp0,pn_pnsp1	system	NULL	NULL	NULL	NULL	1	
 explain partitions select * from t1 where (a IS NULL or a < 2) AND (b=1 OR b=2);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	p0_p0sp0,p0_p0sp1,pn_p3sp0,pn_p3sp1	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	SIMPLE	t1	p0_p0sp0,p0_p0sp1,pn_pnsp0,pn_pnsp1	ALL	NULL	NULL	NULL	NULL	5	Using where
 explain partitions select * from t1 where (a IS NULL or a <= 1) AND (b=1 OR b=2);
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	p0_p0sp0,p0_p0sp1,pn_p3sp0,pn_p3sp1	ALL	NULL	NULL	NULL	NULL	5	Using where
+1	SIMPLE	t1	p0_p0sp0,p0_p0sp1,pn_pnsp0,pn_pnsp1	ALL	NULL	NULL	NULL	NULL	5	Using where
 drop table t1;
 create table t1 ( a int)  partition by list (MOD(a, 10))
 ( partition p0  values in (0), partition p1 values in (1),

mysql-test/r/partition_range.result

@@ -363,3 +363,27 @@ SELECT COUNT(*) FROM t1 WHERE c3 < '2000-12-31';
 COUNT(*)
 10
 DROP TABLE t1;
+create table t1 (a int)
+partition by range (MOD(a,3))
+subpartition by hash(a)
+subpartitions 2
+(partition p0 values less than (1),
+partition p1 values less than (2),
+partition p2 values less than (3),
+partition p3 values less than (4));
+ALTER TABLE t1 DROP PARTITION p3;
+ALTER TABLE t1 DROP PARTITION p1;
+ALTER TABLE t1 DROP PARTITION p2;
+drop table t1;
+create table t1 (a int)
+partition by range (MOD(a,3))
+subpartition by hash(a)
+subpartitions 2
+(partition p0 values less than (1),
+partition p1 values less than (2),
+partition p2 values less than (3),
+partition p3 values less than (4));
+ALTER TABLE t1 DROP PARTITION p0;
+ALTER TABLE t1 DROP PARTITION p1;
+ALTER TABLE t1 DROP PARTITION p2;
+drop table t1;

mysql-test/t/partition_range.test

@@ -388,3 +388,31 @@ SELECT COUNT(*) FROM t1 WHERE c3 BETWEEN '1996-12-31' AND '2000-12-31';
 SELECT COUNT(*) FROM t1 WHERE c3 < '2000-12-31';
 DROP TABLE t1;
 
+#
+# BUG 18962 Errors in DROP PARTITION
+#
+create table t1 (a int)
+partition by range (MOD(a,3))
+subpartition by hash(a)
+subpartitions 2
+(partition p0 values less than (1),
+ partition p1 values less than (2),
+ partition p2 values less than (3),
+ partition p3 values less than (4));
+ALTER TABLE t1 DROP PARTITION p3;
+ALTER TABLE t1 DROP PARTITION p1;
+ALTER TABLE t1 DROP PARTITION p2;
+drop table t1;
+
+create table t1 (a int)
+partition by range (MOD(a,3))
+subpartition by hash(a)
+subpartitions 2
+(partition p0 values less than (1),
+ partition p1 values less than (2),
+ partition p2 values less than (3),
+ partition p3 values less than (4));
+ALTER TABLE t1 DROP PARTITION p0;
+ALTER TABLE t1 DROP PARTITION p1;
+ALTER TABLE t1 DROP PARTITION p2;
+drop table t1;

sql/partition_info.cc

@@ -91,7 +91,7 @@ partition_info *partition_info::get_clone()
 #define MAX_PART_NAME_SIZE 16
 
 char *partition_info::create_default_partition_names(uint part_no, uint no_parts, 
-                                                     uint start_no, bool is_subpart)
+                                                     uint start_no)
 {
   char *ptr= sql_calloc(no_parts*MAX_PART_NAME_SIZE);
   char *move_ptr= ptr;
@@ -102,10 +102,7 @@ char *partition_info::create_default_partition_names(uint part_no, uint no_parts
   {
     do
     {
-      if (is_subpart)
-        my_sprintf(move_ptr, (move_ptr,"p%usp%u", part_no, (start_no + i)));
-      else
-        my_sprintf(move_ptr, (move_ptr,"p%u", (start_no + i)));
+      my_sprintf(move_ptr, (move_ptr,"p%u", (start_no + i)));
       move_ptr+=MAX_PART_NAME_SIZE;
     } while (++i < no_parts);
   }
@@ -117,6 +114,35 @@ char *partition_info::create_default_partition_names(uint part_no, uint no_parts
 }
 
 
+/*
+  Create a unique name for the subpartition as part_name'sp''subpart_no'
+  SYNOPSIS
+    create_subpartition_name()
+    subpart_no                  Number of subpartition
+    part_name                   Name of partition
+  RETURN VALUES
+    >0                          A reference to the created name string
+    0                           Memory allocation error
+*/
+
+char *create_subpartition_name(uint subpart_no, const char *part_name)
+{
+  uint size_alloc= strlen(part_name) + MAX_PART_NAME_SIZE;
+  char *ptr= sql_calloc(size_alloc);
+  DBUG_ENTER("create_subpartition_name");
+
+  if (likely(ptr != NULL))
+  {
+    my_sprintf(ptr, (ptr, "%ssp%u", part_name, subpart_no));
+  }
+  else
+  {
+    mem_alloc_error(size_alloc);
+  }
+  DBUG_RETURN(ptr);
+}
+
+
 /*
   Set up all the default partitions not set-up by the user in the SQL
   statement. Also perform a number of checks that the user hasn't tried
@@ -167,8 +193,7 @@ bool partition_info::set_up_default_partitions(handler *file, ulonglong max_rows
     goto end;
   }
   if (unlikely((!(default_name= create_default_partition_names(0, no_parts,
-                                                               start_no,
-                                                               FALSE)))))
+                                                               start_no)))))
     goto end;
   i= 0;
   do
@@ -238,18 +263,17 @@ bool partition_info::set_up_default_subpartitions(handler *file,
   {
     part_elem= part_it++;
     j= 0;
-    name_ptr= create_default_partition_names(i, no_subparts, (uint)0, TRUE);
-    if (unlikely(!name_ptr))
-      goto end;
     do
     {
       partition_element *subpart_elem= new partition_element();
       if (likely(subpart_elem != 0 &&
           (!part_elem->subpartitions.push_back(subpart_elem))))
       {
+        char *ptr= create_subpartition_name(j, part_elem->partition_name);
+        if (!ptr)
+          goto end;
         subpart_elem->engine_type= default_engine_type;
-        subpart_elem->partition_name= name_ptr;
-        name_ptr+= MAX_PART_NAME_SIZE;
+        subpart_elem->partition_name= ptr;
       }
       else
       {

sql/partition_info.h

@@ -256,7 +256,7 @@ private:
                                  uint start_no);
   bool set_up_default_subpartitions(handler *file, ulonglong max_rows);
   char *create_default_partition_names(uint part_no, uint no_parts,
-                                       uint start_no, bool is_subpart);
+                                       uint start_no);
   bool has_unique_name(partition_element *element);
 };