# HG changeset patch
# User Christian Brabandt <cb@256bit.org>
# Date 1458763205 -3600
# Node ID 39d6e4f2f748b96d8344abe4c23794129f64c6cc
# Parent  e688797c41ff17a39941861e92dad6d6adbd5222
commit https://github.com/vim/vim/commit/ffec3c53496d49668669deabc0724ec78e2274fd
Author: Bram Moolenaar <Bram@vim.org>
Date:   Wed Mar 23 20:55:42 2016 +0100

    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
--- 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 @@ command with 'l'.
 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
diff --git a/src/quickfix.c b/src/quickfix.c
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -1413,6 +1413,33 @@ qf_guess_filepath(char_u *filename)
 }
 
 /*
+ * When loading a file from the quickfix, the auto commands may modify it.
+ * This may invalidate the current quickfix entry.  This function checks
+ * whether a entry is still present in the quickfix.
+ * Similar to location list.
+ */
+    static int
+is_qf_entry_present(qf_info_T *qi, qfline_T *qf_ptr)
+{
+    qf_list_T	*qfl;
+    qfline_T	*qfp;
+    int		i;
+
+    qfl = &qi->qf_lists[qi->qf_curlist];
+
+    /* Search for the entry in the current list */
+    for (i = 0, qfp = qfl->qf_start; i < qfl->qf_count;
+	    ++i, qfp = qfp->qf_next)
+	if (qfp == qf_ptr)
+	    break;
+
+    if (i == qfl->qf_count) /* Entry is not found */
+	return FALSE;
+
+    return TRUE;
+}
+
+/*
  * jump to a quickfix line
  * if dir == FORWARD go "errornr" valid entries forward
  * if dir == BACKWARD go "errornr" valid entries backward
@@ -1794,18 +1821,34 @@ win_found:
 	}
 	else
 	{
+	    int old_qf_curlist = qi->qf_curlist;
+	    int is_abort = FALSE;
+
 	    ok = buflist_getfile(qf_ptr->qf_fnum,
 			    (linenr_T)1, GETF_SETMARK | GETF_SWITCH, forceit);
 	    if (qi != &ql_info && !win_valid(oldwin))
 	    {
 		EMSG(_("E924: Current window was closed"));
+		is_abort = TRUE;
+		opened_window = FALSE;
+	    }
+	    else if (old_qf_curlist != qi->qf_curlist
+		    || !is_qf_entry_present(qi, qf_ptr))
+	    {
+		if (qi == &ql_info)
+		    EMSG(_("E925: Current quickfix was changed"));
+		else
+		    EMSG(_("E926: Current location list was changed"));
+		is_abort = TRUE;
+	    }
+
+	    if (is_abort)
+	    {
 		ok = FALSE;
 		qi = NULL;
 		qf_ptr = NULL;
-		opened_window = FALSE;
 	    }
 	}
-
     }
 
     if (ok == OK)
diff --git a/src/testdir/test_quickfix.vim b/src/testdir/test_quickfix.vim
--- a/src/testdir/test_quickfix.vim
+++ b/src/testdir/test_quickfix.vim
@@ -504,7 +504,7 @@ function Test_locationlist_curwin_was_cl
       autocmd BufReadCmd t call R(expand("<amatch>"))
     augroup END
 
-    function R(n)
+    function! R(n)
       quit
     endfunc
 
@@ -637,3 +637,45 @@ function! Test_efm1()
     call delete('Xerrorfile2')
     call delete('Xtestfile')
 endfunction
+
+function XquickfixChangedByAutocmd(cchar)
+  let Xolder = a:cchar . 'older'
+  let Xgetexpr = a:cchar . 'getexpr'
+  let Xrewind = a:cchar . 'rewind'
+  if a:cchar == 'c'
+    let Xsetlist = 'setqflist('
+    let ErrorNr = 'E925'
+    function! ReadFunc()
+      colder
+      cgetexpr []
+    endfunc
+  else
+    let Xsetlist = 'setloclist(0,'
+    let ErrorNr = 'E926'
+    function! ReadFunc()
+      lolder
+      lgetexpr []
+    endfunc
+  endif
+
+  augroup testgroup
+    au!
+    autocmd BufReadCmd t call ReadFunc()
+  augroup END
+
+  bwipe!
+  let words = [ "a", "b" ]
+  let qflist = []
+  for word in words
+    call add(qflist, {'filename': 't'})
+    exec "call " . Xsetlist . "qflist, '')"
+  endfor
+  exec "call assert_fails('" . Xrewind . "', '" . ErrorNr . ":')"
+
+  augroup! testgroup
+endfunc
+
+function Test_quickfix_was_changed_by_autocmd()
+  call XquickfixChangedByAutocmd('c')
+  call XquickfixChangedByAutocmd('l')
+endfunction
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -749,6 +749,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1640,
+/**/
     1639,
 /**/
     1638,