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+To: vim_dev@googlegroups.com
+Subject: Patch 7.4.901
+Fcc: outbox
+From: Bram Moolenaar <Bram@moolenaar.net>
+Mime-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+------------
+
+Patch 7.4.901
+Problem:    When a BufLeave autocommand changes folding in a way it syncs
+            undo, undo can be corrupted.
+Solution:   Prevent undo sync. (Jacob Niehus)
+Files:      src/popupmnu.c
+
+
+*** ../vim-7.4.900/src/popupmnu.c	2014-07-23 21:10:39.867766788 +0200
+--- src/popupmnu.c	2015-10-30 14:19:21.681104047 +0100
+***************
+*** 568,574 ****
+--- 568,578 ----
+  	    if (p_pvh > 0 && p_pvh < g_do_tagpreview)
+  		g_do_tagpreview = p_pvh;
+  	    ++RedrawingDisabled;
++ 	    /* Prevent undo sync here, if an autocommand syncs undo weird
++ 	     * things can happen to the undo tree. */
++ 	    ++no_u_sync;
+  	    resized = prepare_tagpreview(FALSE);
++ 	    --no_u_sync;
+  	    --RedrawingDisabled;
+  	    g_do_tagpreview = 0;
+  
+***************
+*** 659,665 ****
+--- 663,671 ----
+  			 * redraw. */
+  			if (resized)
+  			{
++ 			    ++no_u_sync;
+  			    win_enter(curwin_save, TRUE);
++ 			    --no_u_sync;
+  			    update_topline();
+  			}
+  
+***************
+*** 670,676 ****
+--- 676,686 ----
+  			pum_do_redraw = FALSE;
+  
+  			if (!resized && win_valid(curwin_save))
++ 			{
++ 			    ++no_u_sync;
+  			    win_enter(curwin_save, TRUE);
++ 			    --no_u_sync;
++ 			}
+  
+  			/* May need to update the screen again when there are
+  			 * autocommands involved. */
+*** ../vim-7.4.900/src/version.c	2015-10-25 22:41:56.703017233 +0100
+--- src/version.c	2015-10-30 14:16:43.274962288 +0100
+***************
+*** 743,744 ****
+--- 743,746 ----
+  {   /* Add new patch number below this line */
++ /**/
++     901,
+  /**/
+
+
+-- 
+Creating the world with Emacs:   M-x let-there-be-light
+Creating the world with Vim:     :make world
+
+ /// Bram Moolenaar -- Bram@Moolenaar.net -- http://www.Moolenaar.net   \\\
+///        sponsor Vim, vote for features -- http://www.Vim.org/sponsor/ \\\
+\\\  an exciting new programming language -- http://www.Zimbu.org        ///
+ \\\            help me help AIDS victims -- http://ICCF-Holland.org    ///