Fix for BUG#2477 "Slave stop with error after master reboot if use HEAP tables":

when we open the HEAP table for the first time since server restart,
in hp_open(), we set a flag to propagate this info to the handler level
which then writes a DELETE FROM this_heap_table to the binlog.
It is not a perfect solution for the bug, because between the server start and 
the first open of the table, the slave still had old data in his table so
a SELECT on the slave may show wrong content. But if there is a --init-file
to populate the HEAP table on master as startup, then this is a safe fix
(I'll put a note about init-file in the HEAP section of the manual).


heap/hp_info.c:
  new info variable implicit_emptied
heap/hp_open.c:
  If this is the first open of the HEAP table, it means it is empty,
  so we mark it.
include/heap.h:
  new variables implicit_emptied
  (we need one in HEAPINFO for the hp_info() call).
sql/ha_heap.cc:
  report info to upper level
sql/handler.h:
  new info 'implicit_emptied' in the handler level; only HEAP uses it.
sql/sql_base.cc:
  When a HEAP table is opened for the first time, write a DELETE FROM to the binlog,
  for replication and mysqlbinlog|mysql.
  Monty: I added the
  entry->file->implicit_emptied= 0;

2 files changed, 11 insertions, 7 deletions

diff --git a/heap/hp_info.c b/heap/hp_info.c
index 3e9d6b6a90b..c8cdfc58c2d 100644
--- a/heap/hp_info.c
+++ b/heap/hp_info.c
@@ -48,12 +48,13 @@ int heap_info(reg1 HP_INFO *info,reg2 HEAPINFO *x,
 	      int flag __attribute__((unused)))
 {
   DBUG_ENTER("heap_info");
-  x->records	 = info->s->records;
-  x->deleted	 = info->s->deleted;
-  x->reclength	 = info->s->reclength;
-  x->data_length = info->s->data_length;
-  x->index_length= info->s->index_length;
-  x->max_records = info->s->max_records;
-  x->errkey	 = info->errkey;
+  x->records         = info->s->records;
+  x->deleted         = info->s->deleted;
+  x->reclength       = info->s->reclength;
+  x->data_length     = info->s->data_length;
+  x->index_length    = info->s->index_length;
+  x->max_records     = info->s->max_records;
+  x->errkey          = info->errkey;
+  x->implicit_emptied= info->implicit_emptied;
   DBUG_RETURN(0);
 } /* heap_info */
diff --git a/heap/hp_open.c b/heap/hp_open.c
index ec8b5fea904..3bf2881667a 100644
--- a/heap/hp_open.c
+++ b/heap/hp_open.c
@@ -30,6 +30,7 @@ HP_INFO *heap_open(const char *name, int mode, uint keys, HP_KEYDEF *keydef,
 		   uint reclength, ulong max_records, ulong min_records)
 {
   uint i,j,key_segs,max_length,length;
+  my_bool implicit_emptied= 0;
   HP_INFO *info;
   HP_SHARE *share;
   HP_KEYSEG *keyseg;
@@ -39,6 +40,7 @@ HP_INFO *heap_open(const char *name, int mode, uint keys, HP_KEYDEF *keydef,
   if (!(share=_hp_find_named_heap(name)))
   {
     DBUG_PRINT("info",("Initializing new table"));
+    implicit_emptied= 1;
     for (i=key_segs=max_length=0 ; i < keys ; i++)
     {
       key_segs+= keydef[i].keysegs;
@@ -127,6 +129,7 @@ HP_INFO *heap_open(const char *name, int mode, uint keys, HP_KEYDEF *keydef,
 #ifndef DBUG_OFF
   info->opt_flag=READ_CHECK_USED;		/* Check when changing */
 #endif
+  info->implicit_emptied= implicit_emptied;
   DBUG_PRINT("exit",("heap: %lx  reclength: %d  records_in_block: %d",
 		     info,share->reclength,share->block.records_in_block));
   DBUG_RETURN(info);