vim-patch:9.0.0260: using freed memory when using 'quickfixtextfunc' recursively

Problem:    Using freed memory when using 'quickfixtextfunc' recursively.
Solution:   Do not allow for recursion.
https://github.com/vim/vim/commit/d6c67629ed05aae436164eec474832daf8ba7420

Cherry-pick Test_qflist_statusmsg() from patch 8.2.4617.

2 files changed, 55 insertions, 0 deletions

diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index d364cebc9d..d680ab8cf3 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -3984,6 +3984,12 @@ static list_T *call_qftf_func(qf_list_T *qfl, int qf_winid, long start_idx, long
 {
   Callback *cb = &qftf_cb;
   list_T *qftf_list = NULL;
+  static bool recursive = false;
+
+  if (recursive) {
+    return NULL;  // this doesn't work properly recursively
+  }
+  recursive = true;
 
   // If 'quickfixtextfunc' is set, then use the user-supplied function to get
   // the text to display. Use the local value of 'quickfixtextfunc' if it is
@@ -4017,6 +4023,7 @@ static list_T *call_qftf_func(qf_list_T *qfl, int qf_winid, long start_idx, long
     tv_dict_unref(dict);
   }
 
+  recursive = false;
   return qftf_list;
 }
 
diff --git a/src/nvim/testdir/test_quickfix.vim b/src/nvim/testdir/test_quickfix.vim
index e19766775d..449904fcb4 100644
--- a/src/nvim/testdir/test_quickfix.vim
+++ b/src/nvim/testdir/test_quickfix.vim
@@ -5839,4 +5839,52 @@ func Test_getqflist_wiped_out_buffer()
   %bw!
 endfunc
 
+" Test for the status message that is displayed when opening a new quickfix
+" list
+func Test_qflist_statusmsg()
+  cexpr "1\n2"
+  cexpr "1\n2\n3\ntest_quickfix.vim:1:msg"
+  call assert_equal('(4 of 4): msg', v:statusmsg)
+  call setqflist([], 'f')
+  %bw!
+
+  " When creating a new quickfix list, if an autocmd changes the quickfix list
+  " in the stack, then an error message should be displayed.
+  augroup QF_Test
+    au!
+    au BufEnter test_quickfix.vim colder
+  augroup END
+  cexpr "1\n2"
+  call assert_fails('cexpr "1\n2\n3\ntest_quickfix.vim:1:msg"', 'E925:')
+  call setqflist([], 'f')
+  augroup QF_Test
+    au!
+  augroup END
+  %bw!
+
+  augroup QF_Test
+    au!
+    au BufEnter test_quickfix.vim caddexpr "4"
+  augroup END
+  call assert_fails('cexpr "1\n2\n3\ntest_quickfix.vim:1:msg"', 'E925:')
+  call setqflist([], 'f')
+  augroup QF_Test
+    au!
+  augroup END
+  %bw!
+endfunc
+
+func Test_quickfixtextfunc_recursive()
+  func s:QFTfunc(o)
+    cgete '0'
+  endfunc
+  copen
+  let &quickfixtextfunc = 's:QFTfunc'
+  cex ""
+
+  let &quickfixtextfunc = ''
+  cclose
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab