patch 8.0.1414: accessing freed memory in :lfile.

Problem:    Accessing freed memory in :lfile.
Solution:   Get the current window after executing autocommands. (Yegappan
            Lakshmanan, closes #2473)

Author: brammool

src/quickfix.c

@@ -4068,10 +4068,6 @@ ex_cfile(exarg_T *eap)
 #endif
     int		res;
 
-    if (eap->cmdidx == CMD_lfile || eap->cmdidx == CMD_lgetfile
-					       || eap->cmdidx == CMD_laddfile)
-	wp = curwin;
-
 #ifdef FEAT_AUTOCMD
     switch (eap->cmdidx)
     {
@@ -4104,6 +4100,11 @@ ex_cfile(exarg_T *eap)
     if (*eap->arg != NUL)
 	set_string_option_direct((char_u *)"ef", -1, eap->arg, OPT_FREE, 0);
 
+    if (eap->cmdidx == CMD_lfile
+	    || eap->cmdidx == CMD_lgetfile
+	    || eap->cmdidx == CMD_laddfile)
+	wp = curwin;
+
     /*
      * This function is used by the :cfile, :cgetfile and :caddfile
      * commands.

src/testdir/test_quickfix.vim

@@ -3031,3 +3031,10 @@ func Test_ll_window_ctx()
   enew | only
 endfunc
 
+" The following test used to crash vim
+func Test_lfile_crash()
+  sp Xtest
+  au QuickFixCmdPre * bw
+  call assert_fails('lfile', 'E40')
+  au! QuickFixCmdPre
+endfunc

src/version.c

@@ -771,6 +771,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1414,
 /**/
     1413,
 /**/