branches/zip: Merge r6198:6206 from branches/5.1:

(r6203 was skipped as it is already in branches/zip)

  ------------------------------------------------------------------------
  r6200 | vasil | 2009-11-19 12:14:23 +0200 (Thu, 19 Nov 2009) | 4 lines
  Changed paths:
     M /branches/5.1/btr/btr0btr.c
  
  branches/5.1:
  
  White space fixup - indent under the opening (
  
  ------------------------------------------------------------------------
  r6203 | jyang | 2009-11-19 15:12:22 +0200 (Thu, 19 Nov 2009) | 8 lines
  Changed paths:
     M /branches/5.1/btr/btr0btr.c
  
  branches/5.1: Use btr_free_root() instead of fseg_free() for
  the fix of bug #48469, because fseg_free() is not defined
  in the zip branch. And we could save one mini-trasaction started
  by fseg_free().
  
  Approved by Marko.
  
  
  ------------------------------------------------------------------------
  r6205 | jyang | 2009-11-20 07:55:48 +0200 (Fri, 20 Nov 2009) | 11 lines
  Changed paths:
     M /branches/5.1/handler/ha_innodb.cc
  
  branches/5.1: Add a special case to handle the Duplicated Key error
  and return DB_ERROR instead. This is to avoid a possible SIGSEGV
  by mysql error handling re-entering the storage layer for dup key
  info without proper table handle.
  This is to prevent a server crash when error situation in bug
  #45961 "DDL on partitioned innodb tables leaves data dictionary
  in an inconsistent state" happens.
  
  rb://157 approved by Sunny Bains.
  
  
  ------------------------------------------------------------------------
  r6206 | jyang | 2009-11-20 09:38:43 +0200 (Fri, 20 Nov 2009) | 5 lines
  Changed paths:
     M /branches/5.1/handler/ha_innodb.cc
  
  branches/5.1: Fix a minor code formating issue for 
  the parenthesis iplacement of the if condition in
  rename_table().
  
  
  ------------------------------------------------------------------------

handler/ha_innodb.cc

@@ -793,6 +793,12 @@ convert_error_code_to_mysql(
 		return(-1); /* unspecified error */
 
 	case DB_DUPLICATE_KEY:
+		/* Be cautious with returning this error, since
+		mysql could re-enter the storage layer to get
+		duplicated key info, the operation requires a
+		valid table handle and/or transaction information,
+		which might not always be available in the error
+		handling stage. */
 		return(HA_ERR_FOUND_DUPP_KEY);
 
 	case DB_FOREIGN_DUPLICATE_KEY:
@@ -6815,6 +6821,24 @@ ha_innobase::rename_table(
 	innobase_commit_low(trx);
 	trx_free_for_mysql(trx);
 
+	/* Add a special case to handle the Duplicated Key error
+	and return DB_ERROR instead.
+	This is to avoid a possible SIGSEGV error from mysql error
+	handling code. Currently, mysql handles the Duplicated Key
+	error by re-entering the storage layer and getting dup key
+	info by calling get_dup_key(). This operation requires a valid
+	table handle ('row_prebuilt_t' structure) which could no
+	longer be available in the error handling stage. The suggested
+	solution is to report a 'table exists' error message (since
+	the dup key error here is due to an existing table whose name
+	is the one we are trying to rename to) and return the generic
+	error code. */
+	if (error == (int) DB_DUPLICATE_KEY) {
+		my_error(ER_TABLE_EXISTS_ERROR, MYF(0), to);
+
+		error = DB_ERROR;
+	}
+
 	error = convert_error_code_to_mysql(error, 0, NULL);
 
 	DBUG_RETURN(error);