vim-patch:9.0.1462: recursively calling :defer function if it does :qa

Problem:    Recursively calling :defer function if it does :qa.
Solution:   Clear the defer entry before calling the function. (closes vim/vim#12266)

https://github.com/vim/vim/commit/42994bf678f46dc9ca66e49f512261da8864fff6

Co-authored-by: Bram Moolenaar <Bram@vim.org>

2 files changed, 18 insertions, 2 deletions

diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index 63d5f94f11..e8b50d8c94 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -3242,12 +3242,24 @@ static void handle_defer_one(funccall_T *funccal)
 {
   for (int idx = funccal->fc_defer.ga_len - 1; idx >= 0; idx--) {
     defer_T *dr = ((defer_T *)funccal->fc_defer.ga_data) + idx;
+
+    if (dr->dr_name == NULL) {
+      // already being called, can happen if function does ":qa"
+      continue;
+    }
+
     funcexe_T funcexe = { .fe_evaluate = true };
+
     typval_T rettv;
     rettv.v_type = VAR_UNKNOWN;     // tv_clear() uses this
-    call_func(dr->dr_name, -1, &rettv, dr->dr_argcount, dr->dr_argvars, &funcexe);
+
+    char *name = dr->dr_name;
+    dr->dr_name = NULL;
+
+    call_func(name, -1, &rettv, dr->dr_argcount, dr->dr_argvars, &funcexe);
+
     tv_clear(&rettv);
-    xfree(dr->dr_name);
+    xfree(name);
     for (int i = dr->dr_argcount - 1; i >= 0; i--) {
       tv_clear(&dr->dr_argvars[i]);
     }
diff --git a/test/old/testdir/test_user_func.vim b/test/old/testdir/test_user_func.vim
index 0f9b40814c..d217ca8c69 100644
--- a/test/old/testdir/test_user_func.vim
+++ b/test/old/testdir/test_user_func.vim
@@ -614,6 +614,7 @@ func Test_defer_quitall()
       " vim9script
       func DeferLevelTwo()
         call writefile(['text'], 'XQuitallTwo', 'D')
+        call writefile(['quit'], 'XQuitallThree', 'a')
         qa!
       endfunc
 
@@ -632,6 +633,9 @@ func Test_defer_quitall()
   call assert_equal(0, v:shell_error)
   call assert_false(filereadable('XQuitallOne'))
   call assert_false(filereadable('XQuitallTwo'))
+  call assert_equal(['quit'], readfile('XQuitallThree'))
+
+  call delete('XQuitallThree')
 endfunc
 
 func Test_defer_quitall_in_expr_func()