bk commit into 5.1 tree (kostja:1.2613) BUG#12713

[konstantin]

Below is the list of changes that have just been committed into a local
5.1 repository of kostja. When kostja does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2007-11-01 18:06:46+03:00, kostja@bodhi.(none) +1 -0
  Use Internal_error_handler mechanism to silence ER_TOO_MANY_FIELDS
  error in mysql_create_frm instead of
  direct access to my_error() members.
  
  This is a pre-requisite for the patch for Bug#12713.

  sql/unireg.cc@stripped, 2007-11-01 18:06:44+03:00, kostja@bodhi.(none) +42 -6
    Use Internal_error_handler mechanism to silence ER_TOO_MANY_FIELDS
    error in mysql_create_frm instead of
    direct access to my_error() members.

diff -Nrup a/sql/unireg.cc b/sql/unireg.cc
--- a/sql/unireg.cc	2007-07-11 12:57:47 +04:00
+++ b/sql/unireg.cc	2007-11-01 18:06:44 +03:00
@@ -47,6 +47,35 @@ static bool make_empty_rec(THD *thd, int
 			   uint reclength, ulong data_offset,
                            handler *handler);
 
+/**
+  An interceptor to hijack ER_TOO_MANY_FIELDS error from
+  pack_screens and retry again without UNIREG screens.
+
+  XXX: what is a UNIREG  screen?
+*/
+
+struct Pack_header_error_handler: public Internal_error_handler
+{
+  virtual bool handle_error(uint sql_errno,
+                            const char *message,
+                            MYSQL_ERROR::enum_warning_level level,
+                            THD *thd);
+  bool is_handled;
+  Pack_header_error_handler() :is_handled(FALSE) {}
+};
+
+
+bool
+Pack_header_error_handler::
+handle_error(uint sql_errno,
+             const char * /* message */,
+             MYSQL_ERROR::enum_warning_level /* level */,
+             THD * /* thd */)
+{
+  is_handled= (sql_errno == ER_TOO_MANY_FIELDS);
+  return is_handled;
+}
+
 /*
   Create a frm (table definition) file
 
@@ -86,6 +115,8 @@ bool mysql_create_frm(THD *thd, const ch
 #ifdef WITH_PARTITION_STORAGE_ENGINE
   partition_info *part_info= thd->work_part_info;
 #endif
+  Pack_header_error_handler pack_header_error_handler;
+  int error;
   DBUG_ENTER("mysql_create_frm");
 
   DBUG_ASSERT(*fn_rext((char*)file_name)); // Check .frm extension
@@ -99,17 +130,22 @@ bool mysql_create_frm(THD *thd, const ch
     create_info->null_bits++;
   data_offset= (create_info->null_bits + 7) / 8;
 
-  if (pack_header(forminfo, ha_legacy_type(create_info->db_type),
-                  create_fields,info_length,
-		  screens, create_info->table_options,
-                  data_offset, db_file))
+  thd->push_internal_handler(&pack_header_error_handler);
+
+  error= pack_header(forminfo, ha_legacy_type(create_info->db_type),
+                     create_fields,info_length,
+                     screens, create_info->table_options,
+                     data_offset, db_file);
+
+  thd->pop_internal_handler();
+
+  if (error)
   {
     my_free(screen_buff, MYF(0));
-    if (thd->net.last_errno != ER_TOO_MANY_FIELDS)
+    if (! pack_header_error_handler.is_handled)
       DBUG_RETURN(1);
 
     // Try again without UNIREG screens (to get more columns)
-    thd->net.last_error[0]=0;
     if (!(screen_buff=pack_screens(create_fields,&info_length,&screens,1)))
       DBUG_RETURN(1);
     if (pack_header(forminfo, ha_legacy_type(create_info->db_type),