vim-patch:9.0.0406: deferred functions not invoked when partial func exits

Problem:    Deferred functions not invoked when partial func exits.
Solution:   Create a funccall_T when calling a :def function.

9667b2c888

The remove_funccal() function is currently unused, but it will be used
in patch 9.0.0618.

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

src/nvim/eval/userfunc.c

@@ -881,6 +881,27 @@ static void func_clear_free(ufunc_T *fp, bool force)
   func_free(fp);
 }
 
+/// Allocate a funccall_T, link it in current_funccal and fill in "fp" and "rettv".
+/// Must be followed by one call to remove_funccal() or cleanup_function_call().
+funccall_T *create_funccal(ufunc_T *fp, typval_T *rettv)
+{
+  funccall_T *fc = xcalloc(1, sizeof(funccall_T));
+  fc->fc_caller = current_funccal;
+  current_funccal = fc;
+  fc->fc_func = fp;
+  func_ptr_ref(fp);
+  fc->fc_rettv = rettv;
+  return fc;
+}
+
+/// Restore current_funccal.
+void remove_funccal(void)
+{
+  funccall_T *fc = current_funccal;
+  current_funccal = fc->fc_caller;
+  free_funccal(fc);
+}
+
 /// Call a user function
 ///
 /// @param fp  Function to call.
@@ -895,7 +916,6 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
   FUNC_ATTR_NONNULL_ARG(1, 3, 4)
 {
   bool using_sandbox = false;
-  funccall_T *fc;
   int save_did_emsg;
   static int depth = 0;
   dictitem_T *v;
@@ -930,19 +950,13 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
   // check for CTRL-C hit
   line_breakcheck();
   // prepare the funccall_T structure
-  fc = xcalloc(1, sizeof(funccall_T));
+  funccall_T *fc = create_funccal(fp, rettv);
-  fc->fc_caller = current_funccal;
-  current_funccal = fc;
-  fc->fc_func = fp;
-  fc->fc_rettv = rettv;
   fc->fc_level = ex_nesting_level;
   // Check if this function has a breakpoint.
   fc->fc_breakpoint = dbg_find_breakpoint(false, fp->uf_name, (linenr_T)0);
   fc->fc_dbg_tick = debug_tick;
-
   // Set up fields for closure.
   ga_init(&fc->fc_ufuncs, sizeof(ufunc_T *), 1);
-  func_ptr_ref(fp);
 
   if (strncmp(fp->uf_name, "<lambda>", 8) == 0) {
     islambda = true;

test/old/testdir/test_user_func.vim

@@ -633,5 +633,34 @@ func Test_defer_quitall()
   call assert_false(filereadable('XQuitallTwo'))
 endfunc
 
+func Test_defer_quitall_in_expr_func()
+  throw 'Skipped: Vim9 script is N/A'
+  let lines =<< trim END
+      def DefIndex(idx: number, val: string): bool
+        call writefile([idx .. ': ' .. val], 'Xentry' .. idx, 'D')
+        if val == 'b'
+          qa!
+        endif
+        return val == 'c'
+      enddef
+
+      def Test_defer_in_funcref()
+        assert_equal(2, indexof(['a', 'b', 'c'], funcref('g:DefIndex')))
+      enddef
+      call Test_defer_in_funcref()
+  END
+  call writefile(lines, 'XdeferQuitallExpr', 'D')
+  let res = system(GetVimCommandClean() .. ' -X -S XdeferQuitallExpr')
+  call assert_equal(0, v:shell_error)
+  call assert_false(filereadable('Xentry0'))
+  call assert_false(filereadable('Xentry1'))
+  call assert_false(filereadable('Xentry2'))
+endfunc
+
+func FuncIndex(idx, val)
+  call writefile([a:idx .. ': ' .. a:val], 'Xentry' .. a:idx, 'D')
+  return a:val == 'c'
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab