patch 8.2.1096: Vim9: return type of getqflist() is wrong

Problem:    Vim9: return type of getqflist() is wrong.
Solution:   Let the return type depend on the arguments.  Also for
            getloclist(). (closes #6367)

src/evalfunc.c

@@ -347,6 +347,30 @@ ret_first_arg(int argcount, type_T **argtypes)
     return &t_void;
 }
 
+/*
+ * Used for getqflist(): returns list if there is no argument, dict if there is
+ * one.
+ */
+    static type_T *
+ret_list_or_dict_0(int argcount, type_T **argtypes UNUSED)
+{
+    if (argcount > 0)
+	return &t_dict_any;
+    return &t_list_dict_any;
+}
+
+/*
+ * Used for getloclist(): returns list if there is one argument, dict if there
+ * are two.
+ */
+    static type_T *
+ret_list_or_dict_1(int argcount, type_T **argtypes UNUSED)
+{
+    if (argcount > 1)
+	return &t_dict_any;
+    return &t_list_dict_any;
+}
+
 static type_T *ret_f_function(int argcount, type_T **argtypes);
 
 /*
@@ -588,13 +612,13 @@ static funcentry_T global_functions[] =
     {"getimstatus",	0, 0, 0,	  ret_number,	f_getimstatus},
     {"getjumplist",	0, 2, FEARG_1,	  ret_list_any,	f_getjumplist},
     {"getline",		1, 2, FEARG_1,	  ret_f_getline, f_getline},
-    {"getloclist",	1, 2, 0,	  ret_list_dict_any, f_getloclist},
+    {"getloclist",	1, 2, 0,	  ret_list_or_dict_1, f_getloclist},
     {"getmarklist",	0, 1, FEARG_1,	  ret_list_dict_any,  f_getmarklist},
     {"getmatches",	0, 1, 0,	  ret_list_dict_any, f_getmatches},
     {"getmousepos",	0, 0, 0,	  ret_dict_number, f_getmousepos},
     {"getpid",		0, 0, 0,	  ret_number,	f_getpid},
     {"getpos",		1, 1, FEARG_1,	  ret_list_number,	f_getpos},
-    {"getqflist",	0, 1, 0,	  ret_list_dict_any,	f_getqflist},
+    {"getqflist",	0, 1, 0,	  ret_list_or_dict_0,	f_getqflist},
     {"getreg",		0, 3, FEARG_1,	  ret_string,	f_getreg},
     {"getreginfo",	0, 1, FEARG_1,	  ret_dict_any,	f_getreginfo},
     {"getregtype",	0, 1, FEARG_1,	  ret_string,	f_getregtype},

src/testdir/test_vim9_func.vim

@@ -837,6 +837,22 @@ def Test_sort_return_type()
   res = [1, 2, 3]->sort()
 enddef
 
+def Test_getqflist_return_type()
+  let l = getqflist()
+  assert_equal([], l)
+
+  let d = getqflist(#{items: 0})
+  assert_equal(#{items: []}, d)
+enddef
+
+def Test_getloclist_return_type()
+  let l = getloclist(1)
+  assert_equal([], l)
+
+  let d = getloclist(1, #{items: 0})
+  assert_equal(#{items: []}, d)
+enddef
+
 def Line_continuation_in_def(dir: string = ''): string
     let path: string = empty(dir)
             \ ? 'empty'

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1096,
 /**/
     1095,
 /**/