Fix tmp table patch

sql/handler.cc

@@ -5113,22 +5113,19 @@ static my_bool discover_handlerton(THD *thd, plugin_ref plugin,
 int ha_discover_table(THD *thd, TABLE_SHARE *share)
 {
   DBUG_ENTER("ha_discover_table");
-  int found;
-
   DBUG_ASSERT(share->error == OPEN_FRM_OPEN_ERROR);   // share is not OK yet
+  int found = 0;
 
-  if (!engines_with_discover)
-    found= FALSE;
-  else if (share->db_plugin)
-    found= discover_handlerton(thd, share->db_plugin, share);
-  else
-    found= plugin_foreach(thd, discover_handlerton,
-                        MYSQL_STORAGE_ENGINE_PLUGIN, share);
-  
-  if (!found)
-    open_table_error(share, OPEN_FRM_OPEN_ERROR, ENOENT); // not found
+  if (engines_with_discover)
+  {
+    if (share->db_plugin)
+      found = discover_handlerton(thd, share->db_plugin, share);
+    else
+      found = plugin_foreach(thd, discover_handlerton,
+                     MYSQL_STORAGE_ENGINE_PLUGIN, share);
+  }
 
-  DBUG_RETURN(share->error != OPEN_FRM_OK);
+  DBUG_RETURN(found);
 }
 
 static my_bool file_ext_exists(char *path, size_t path_len, const char *ext)
@@ -5163,43 +5160,6 @@ static my_bool discover_existence(THD *thd, plugin_ref plugin,
   return ht->discover_table_existence(ht, args->db, args->table_name);
 }
 
-class Table_exists_error_handler : public Internal_error_handler
-{
-public:
-  Table_exists_error_handler()
-    : m_handled_errors(0), m_unhandled_errors(0)
-  {}
-
-  bool handle_condition(THD *thd,
-                        uint sql_errno,
-                        const char* sqlstate,
-                        Sql_condition::enum_warning_level *level,
-                        const char* msg,
-                        Sql_condition ** cond_hdl)
-  {
-    *cond_hdl= NULL;
-    if (sql_errno == ER_NO_SUCH_TABLE ||
-        sql_errno == ER_NO_SUCH_TABLE_IN_ENGINE ||
-        sql_errno == ER_WRONG_OBJECT)
-    {
-      m_handled_errors++;
-      return TRUE;
-    }
-
-    if (*level == Sql_condition::WARN_LEVEL_ERROR)
-      m_unhandled_errors++;
-    return FALSE;
-  }
-
-  bool safely_trapped_errors()
-  {
-    return ((m_handled_errors > 0) && (m_unhandled_errors == 0));
-  }
-
-private:
-  int m_handled_errors;
-  int m_unhandled_errors;
-};
 
 /**
   Check if a given table exists, without doing a full discover, if possible
@@ -5298,24 +5258,24 @@ bool ha_table_exists(THD *thd, const LEX_CSTRING *db, const LEX_CSTRING *table_n
   if (need_full_discover_for_existence)
   {
     TABLE_LIST table;
-    uint flags = GTS_TABLE | GTS_VIEW;
+    uint flags = GTS_TABLE | GTS_VIEW | GTS_NO_ERROR_IF_MISSING;
     if (!hton)
       flags|= GTS_NOLOCK;
 
-    Table_exists_error_handler no_such_table_handler;
-    thd->push_internal_handler(&no_such_table_handler);
     table.init_one_table(db, table_name, 0, TL_READ);
     TABLE_SHARE *share= tdc_acquire_share(thd, &table, flags);
-    thd->pop_internal_handler();
 
-    if (hton && share)
+    // Share returned, table exists.
+    if (share)
     {
-      *hton= share->db_type();
+      if (hton)
+        *hton= share->db_type();
       tdc_release_share(share);
+      DBUG_RETURN(TRUE);
     }
-
-    // the table doesn't exist if we've caught ER_NO_SUCH_TABLE and nothing else
-    DBUG_RETURN(!no_such_table_handler.safely_trapped_errors());
+    // No share, if errors have been reported, we assume the table exists.
+    if (thd->is_error())
+      DBUG_RETURN(TRUE);
   }
 
   DBUG_RETURN(FALSE);

sql/table.cc

@@ -573,7 +573,6 @@ inline bool is_system_table_name(const char *name, size_t length)
 
 enum open_frm_error open_table_def(THD *thd, TABLE_SHARE *share, uint flags)
 {
-  bool error_given= false;
   File file;
   uchar *buf;
   uchar head[FRM_HEADER_SIZE];
@@ -602,8 +601,9 @@ enum open_frm_error open_table_def(THD *thd, TABLE_SHARE *share, uint flags)
   {
     if ((flags & GTS_TABLE) && (flags & GTS_USE_DISCOVERY))
     {
-      ha_discover_table(thd, share);
-      error_given= true;
+      if (!ha_discover_table(thd, share) && !(flags & GTS_NO_ERROR_IF_MISSING))
+          open_table_error(share, OPEN_FRM_OPEN_ERROR, ENOENT);
+      DBUG_RETURN(share->error);
     }
     goto err_not_open;
   }
@@ -668,16 +668,14 @@ enum open_frm_error open_table_def(THD *thd, TABLE_SHARE *share, uint flags)
   frmlen= read_length + sizeof(head);
 
   share->init_from_binary_frm_image(thd, false, buf, frmlen);
-  error_given= true; // init_from_binary_frm_image has already called my_error()
   my_free(buf);
-
-  goto err_not_open;
+  DBUG_RETURN(share->error);
 
 err:
   mysql_file_close(file, MYF(MY_WME));
 
 err_not_open:
-  if (unlikely(share->error && !error_given))
+  if (unlikely(share->error))
   {
     share->open_errno= my_errno;
     open_table_error(share, share->error, share->open_errno);

sql/table.h

@@ -2876,7 +2876,8 @@ enum get_table_share_flags {
   GTS_VIEW                 = 2,
   GTS_NOLOCK               = 4,
   GTS_USE_DISCOVERY        = 8,
-  GTS_FORCE_DISCOVERY      = 16
+  GTS_FORCE_DISCOVERY      = 16,
+  GTS_NO_ERROR_IF_MISSING  = 32,
 };
 
 size_t max_row_length(TABLE *table, MY_BITMAP const *cols, const uchar *data);