vim-patch:9.0.1540: reverse() on string doesn't work in compiled function

Problem:    reverse() on string doesn't work in compiled function.
Solution:   Accept string in argument type check. (Yegappan Lakshmanan,
            closes vim/vim#12377)

f9dc278946

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

src/nvim/eval/funcs.c

@@ -6199,6 +6199,10 @@ static void f_resolve(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "reverse({list})" function
 static void f_reverse(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
+  if (tv_check_for_string_or_list_or_blob_arg(argvars, 0) == FAIL) {
+    return;
+  }
+
   if (argvars[0].v_type == VAR_BLOB) {
     blob_T *const b = argvars[0].vval.v_blob;
     const int len = tv_blob_len(b);
@@ -6216,9 +6220,7 @@ static void f_reverse(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     } else {
       rettv->vval.v_string = NULL;
     }
-  } else if (argvars[0].v_type != VAR_LIST) {
+  } else if (argvars[0].v_type == VAR_LIST) {
-    semsg(_(e_listblobarg), "reverse()");
-  } else {
     list_T *const l = argvars[0].vval.v_list;
     if (!value_check_lock(tv_list_locked(l), N_("reverse() argument"),
                           TV_TRANSLATE)) {

src/nvim/eval/typval.c

@@ -81,6 +81,8 @@ static const char e_blob_required_for_argument_nr[]
   = N_("E1238: Blob required for argument %d");
 static const char e_invalid_value_for_blob_nr[]
   = N_("E1239: Invalid value for blob: %d");
+static const char e_string_list_or_blob_required_for_argument_nr[]
+  = N_("E1252: String, List or Blob required for argument %d");
 static const char e_string_or_function_required_for_argument_nr[]
   = N_("E1256: String or function required for argument %d");
 static const char e_non_null_dict_required_for_argument_nr[]
@@ -4350,7 +4352,20 @@ int tv_check_for_string_or_list_arg(const typval_T *const args, const int idx)
   return OK;
 }
 
-/// Check for an optional string or list argument at 'idx'
+/// Give an error and return FAIL unless "args[idx]" is a string, a list or a blob.
+int tv_check_for_string_or_list_or_blob_arg(const typval_T *const args, const int idx)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  if (args[idx].v_type != VAR_STRING
+      && args[idx].v_type != VAR_LIST
+      && args[idx].v_type != VAR_BLOB) {
+    semsg(_(e_string_list_or_blob_required_for_argument_nr), idx + 1);
+    return FAIL;
+  }
+  return OK;
+}
+
+/// Check for an optional string or list argument at "idx"
 int tv_check_for_opt_string_or_list_arg(const typval_T *const args, const int idx)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {

test/old/testdir/test_functions.vim

@@ -3150,13 +3150,16 @@ endfunc
 
 " Test for the reverse() function with a string
 func Test_string_reverse()
-  call assert_equal('', reverse(v:_null_string))
+  let lines =<< trim END
-  for [s1, s2] in [['', ''], ['a', 'a'], ['ab', 'ba'], ['abc', 'cba'],
+    call assert_equal('', reverse(v:_null_string))
-        \ ['abcd', 'dcba'], ['«-«-»-»', '»-»-«-«'],
+    for [s1, s2] in [['', ''], ['a', 'a'], ['ab', 'ba'], ['abc', 'cba'],
-        \ ['🇦', '🇦'], ['🇦🇧', '🇧🇦'], ['🇦🇧🇨', '🇨🇧🇦'],
+                   \ ['abcd', 'dcba'], ['«-«-»-»', '»-»-«-«'],
-        \ ['🇦«🇧-🇨»🇩', '🇩»🇨-🇧«🇦']]
+                   \ ['🇦', '🇦'], ['🇦🇧', '🇧🇦'], ['🇦🇧🇨', '🇨🇧🇦'],
-    call assert_equal(s2, reverse(s1))
+                   \ ['🇦«🇧-🇨»🇩', '🇩»🇨-🇧«🇦']]
-  endfor
+      call assert_equal(s2, reverse(s1))
+    endfor
+  END
+  call CheckLegacyAndVim9Success(lines)
 
   " test in latin1 encoding
   let save_enc = &encoding

test/old/testdir/test_listdict.vim

@@ -894,7 +894,7 @@ func Test_reverse_sort_uniq()
   END
   call CheckLegacyAndVim9Success(lines)
 
-  call assert_fails('call reverse({})', 'E899:')
+  call assert_fails('call reverse({})', 'E1252:')
   call assert_fails('call uniq([1, 2], {x, y -> []})', 'E745:')
   call assert_fails("call sort([1, 2], function('min'), 1)", "E1206:")
   call assert_fails("call sort([1, 2], function('invalid_func'))", "E700:")

test/old/testdir/test_method.vim

@@ -63,7 +63,7 @@ func Test_dict_method()
   call assert_equal(2, d->remove("two"))
   let d.two = 2
   call assert_fails('let x = d->repeat(2)', 'E731:')
-  call assert_fails('let x = d->reverse()', 'E899:')
+  call assert_fails('let x = d->reverse()', 'E1252:')
   call assert_fails('let x = d->sort()', 'E686:')
   call assert_equal("{'one': 1, 'two': 2, 'three': 3}", d->string())
   call assert_equal(v:t_dict, d->type())