More strict checks for the undo file.

runtime/doc/tags

@@ -4166,7 +4166,17 @@ E819	editing.txt	/*E819*
 E82	message.txt	/*E82*
 E820	editing.txt	/*E820*
 E821	options.txt	/*E821*
+E822	undo.txt	/*E822*
+E823	undo.txt	/*E823*
+E824	undo.txt	/*E824*
+E825	undo.txt	/*E825*
+E826	undo.txt	/*E826*
+E827	undo.txt	/*E827*
+E828	undo.txt	/*E828*
+E829	undo.txt	/*E829*
 E83	message.txt	/*E83*
+E830	undo.txt	/*E830*
+E831	undo.txt	/*E831*
 E84	windows.txt	/*E84*
 E85	options.txt	/*E85*
 E86	windows.txt	/*E86*

runtime/doc/todo.txt

@@ -33,6 +33,9 @@ be worked on, but only if you sponsor Vim development.  See |sponsor|.
 When Vim crashes it may run out of stack while executing autocommands.  Patch
 to not run autocommands when leaving Vim? (James Vega, 2010 May 23)
 
+Invalid memory access when deleting funcref variable.  Patch by Lech Lorens,
+2010 May 25.
+
 Cursor positioning wrong with 0x200e character. (John Becket, 2010 May 6)
 
 E315 when trying to change a file in FileChangedRO autocommand event.
@@ -1094,8 +1097,12 @@ Vim 7.3:
   Wait until window is gone with EnumWindows (see os_win32.c).
 Patches to include:
 - Persistent undo bugs / fixes:
-    - Add undofile(name): get undo file name for buffer "name".
+    - Patch not to allocate extra byte in U_ALLOC_LINE() (Dominique, 2010 May
+      25)
+    - Remove the old code when U_USE_MALLOC is not defined?
     - When there is no undo info (undolevels negative), delete the undo file.
+    - Need to check all values for evil manipulation.
+    - Add undofile(name): get undo file name for buffer "name".
 - Extend test62 for gettabvar() and settabvar(). (Yegappan Lakshmanan, 2010
   May 23)
 - Also crypt the undo file.

runtime/doc/undo.txt

@@ -267,8 +267,8 @@ Reading an existing undo file may fail for several reasons:
 	The file text differs from when the undo file was written.  This means
 	the undo file cannot be used, it would corrupt the text.  This also
 	happens when 'encoding' differs from when the undo file was written.
-*E825* *E826*	The undo file does not contain valid contents and cannot be
-	used.
+*E825* *E826* *E831*
+	The undo file does not contain valid contents and cannot be used.
 *E827*	The magic number at the end of the file was not found.  This usually
 	means the file was truncated.