patch 7.4.1591
Problem:    The quickfix title is truncated.
Solution:   Save the command before it is truncated. (Anton Lindqvist)
diff --git a/src/testdir/test_quickfix.vim b/src/testdir/test_quickfix.vim
index d551feb..5982aee 100644
--- a/src/testdir/test_quickfix.vim
+++ b/src/testdir/test_quickfix.vim
@@ -317,6 +317,23 @@
   augroup! QfBufWinEnter
 endfunc
 
+func Test_vimgreptitle()
+  augroup QfBufWinEnter
+    au!
+    au BufWinEnter * :let g:a=get(w:, 'quickfix_title', 'NONE')
+  augroup END
+  try
+    vimgrep /pattern/j file
+  catch /E480/
+  endtry
+  copen
+  call assert_equal(':    vimgrep /pattern/j file', g:a)
+  augroup QfBufWinEnter
+    au!
+  augroup END
+  augroup! QfBufWinEnter
+endfunc
+
 function XqfTitleTests(cchar)
   let Xgetexpr = a:cchar . 'getexpr'
   if a:cchar == 'c'