patch 7.4.1640
Problem:    Crash when an autocommand changes a quickfix list. (Dominique)
Solution:   Check wether an entry is still valid. (Yegappan Lakshmanan,
            Hirohito Higashi)
diff --git a/runtime/doc/quickfix.txt b/runtime/doc/quickfix.txt
index 0ca314d..a4c1208 100644
--- a/runtime/doc/quickfix.txt
+++ b/runtime/doc/quickfix.txt
@@ -1,4 +1,4 @@
-*quickfix.txt*  For Vim version 7.4.  Last change: 2016 Mar 19
+*quickfix.txt*  For Vim version 7.4.  Last change: 2016 Mar 23
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -60,6 +60,10 @@
 If the current window was closed by an |autocommand| while processing a
 location list command, it will be aborted.
 
+							*E925* *E926*
+If the current quickfix or location list was changed by an |autocommand| while
+processing a quickfix or location list command, it will be aborted.
+
 							*:cc*
 :cc[!] [nr]		Display error [nr].  If [nr] is omitted, the same
 			error is displayed again.  Without [!] this doesn't