bug: ha_heap was unilaterally increasing reclength

proper fix replacing the hack from b80fa40

don't confuse length of the data area (reclength) with the
offset to the "deleted" mark.

include/heap.h

@@ -144,6 +144,7 @@ typedef struct st_heap_share
   uint key_version;                     /* Updated on key change */
   uint file_version;                    /* Update on clear */
   uint reclength;			/* Length of one record */
+  uint visible;                         /* Offset to the visible/deleted mark */
   uint changed;
   uint keys,max_key_length;
   uint currently_disabled_keys;    /* saved value from "keys" when disabled */

storage/heap/_check.c

@@ -79,7 +79,7 @@ int heap_check_heap(HP_INFO *info, my_bool print_status)
     }
     hp_find_record(info,pos);
 
-    if (!info->current_ptr[share->reclength])
+    if (!info->current_ptr[share->visible])
       deleted++;
     else
       records++;

storage/heap/ha_heap.cc

@@ -100,15 +100,6 @@ const char **ha_heap::bas_ext() const
 
 int ha_heap::open(const char *name, int mode, uint test_if_locked)
 {
-  if (table->s->reclength < sizeof (char*))
-  {
-    MEM_UNDEFINED(table->s->default_values + table->s->reclength,
-                  sizeof(char*) - table->s->reclength);
-    table->s->reclength= sizeof(char*);
-    MEM_UNDEFINED(table->record[0], table->s->reclength);
-    MEM_UNDEFINED(table->record[1], table->s->reclength);
-  }
-
   internal_table= test(test_if_locked & HA_OPEN_INTERNAL_TABLE);
   if (internal_table || (!(file= heap_open(name, mode)) && my_errno == ENOENT))
   {
@@ -736,7 +727,7 @@ heap_prepare_hp_create_info(TABLE *table_arg, bool internal_table,
       }
     }
   }
-  mem_per_row+= MY_ALIGN(share->reclength + 1, sizeof(char*));
+  mem_per_row+= MY_ALIGN(max(share->reclength, sizeof(char*)) + 1, sizeof(char*));
   if (table_arg->found_next_number_field)
   {
     keydef[share->next_number_index].flag|= HA_AUTO_KEY;

storage/heap/hp_create.c

@@ -33,6 +33,7 @@ int heap_create(const char *name, HP_CREATE_INFO *create_info,
   uint keys= create_info->keys;
   ulong min_records= create_info->min_records;
   ulong max_records= create_info->max_records;
+  uint visible_offset;
   DBUG_ENTER("heap_create");
 
   if (!create_info->internal_table)
@@ -58,9 +59,9 @@ int heap_create(const char *name, HP_CREATE_INFO *create_info,
 
     /*
       We have to store sometimes uchar* del_link in records,
-      so the record length should be at least sizeof(uchar*)
+      so the visible_offset must be least at sizeof(uchar*)
     */
-    set_if_bigger(reclength, sizeof (uchar*));
+    visible_offset= max(reclength, sizeof (char*));
 
     for (i= key_segs= max_length= 0, keyinfo= keydef; i < keys; i++, keyinfo++)
     {
@@ -152,7 +153,7 @@ int heap_create(const char *name, HP_CREATE_INFO *create_info,
     share->keydef= (HP_KEYDEF*) (share + 1);
     share->key_stat_version= 1;
     keyseg= (HA_KEYSEG*) (share->keydef + keys);
-    init_block(&share->block, reclength + 1, min_records, max_records);
+    init_block(&share->block, visible_offset + 1, min_records, max_records);
 	/* Fix keys */
     memcpy(share->keydef, keydef, (size_t) (sizeof(keydef[0]) * keys));
     for (i= 0, keyinfo= share->keydef; i < keys; i++, keyinfo++)
@@ -192,6 +193,7 @@ int heap_create(const char *name, HP_CREATE_INFO *create_info,
     share->max_table_size= create_info->max_table_size;
     share->data_length= share->index_length= 0;
     share->reclength= reclength;
+    share->visible= visible_offset;
     share->blength= 1;
     share->keys= keys;
     share->max_key_length= max_length;

storage/heap/hp_delete.c

@@ -45,7 +45,7 @@ int heap_delete(HP_INFO *info, const uchar *record)
   info->update=HA_STATE_DELETED;
   *((uchar**) pos)=share->del_link;
   share->del_link=pos;
-  pos[share->reclength]=0;		/* Record deleted */
+  pos[share->visible]=0;		/* Record deleted */
   share->deleted++;
   share->key_version++;
 #if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)

storage/heap/hp_rrnd.c

@@ -37,7 +37,7 @@ int heap_rrnd(register HP_INFO *info, uchar *record, uchar *pos)
     info->update= 0;
     DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
   }
-  if (!info->current_ptr[share->reclength])
+  if (!info->current_ptr[share->visible])
   {
     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
     DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
@@ -91,7 +91,7 @@ int heap_rrnd_old(register HP_INFO *info, uchar *record, ulong pos)
   hp_find_record(info, pos);
 
 end:
-  if (!info->current_ptr[share->reclength])
+  if (!info->current_ptr[share->visible])
   {
     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
     DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);

storage/heap/hp_rsame.c

@@ -32,7 +32,7 @@ int heap_rsame(register HP_INFO *info, uchar *record, int inx)
   DBUG_ENTER("heap_rsame");
 
   test_active(info);
-  if (info->current_ptr[share->reclength])
+  if (info->current_ptr[share->visible])
   {
     if (inx < -1 || inx >= (int) share->keys)
     {

storage/heap/hp_scan.c

@@ -62,7 +62,7 @@ int heap_scan(register HP_INFO *info, uchar *record)
     }
     hp_find_record(info, pos);
   }
-  if (!info->current_ptr[share->reclength])
+  if (!info->current_ptr[share->visible])
   {
     DBUG_PRINT("warning",("Found deleted record"));
     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;

storage/heap/hp_write.c

@@ -54,7 +54,7 @@ int heap_write(HP_INFO *info, const uchar *record)
   }
 
   memcpy(pos,record,(size_t) share->reclength);
-  pos[share->reclength]=1;		/* Mark record as not deleted */
+  pos[share->visible]= 1;                     /* Mark record as not deleted */
   if (++share->records == share->blength)
     share->blength+= share->blength;
   info->s->key_version++;
@@ -92,7 +92,7 @@ int heap_write(HP_INFO *info, const uchar *record)
   share->deleted++;
   *((uchar**) pos)=share->del_link;
   share->del_link=pos;
-  pos[share->reclength]=0;			/* Record deleted */
+  pos[share->visible]= 0;                                 /* Record deleted */
 
   DBUG_RETURN(my_errno);
 } /* heap_write */