patch 9.2.1242: Vim9: list instead of tuple for rest of tuple in a :for loop

Problem:  Vim9: In a compiled function, when unpacking a tuple in a :for
          loop, the variable after ";" gets a list with the remaining
          items instead of a tuple.
Solution: Create a tuple with the remaining items (Yegappan Lakshmanan).

The help says that the variable after ";" gets a tuple, this was already
the case when not in a compiled function.

fixes:  #21587
closes: #21588

Assisted-by: Claude Code (Claude Opus 5.5)
Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_tuple.vim

@@ -787,6 +787,20 @@ func Test_multi_assign_from_tuple()
   call v9.CheckSourceFailure(lines, 'E1093: Expected 2 items but got 0')
 endfunc
 
+" Test for the value of the variable after ";" when unpacking a tuple in a
+" :for loop.  It must be a tuple, also in a compiled function.
+def Test_tuple_for_unpack_rest_is_tuple()
+  var lines =<< trim END
+    var r = []
+    for [a; b] in ((1, 2, 3), (4,))
+      assert_equal(v:t_tuple, type(b))
+      r->add(b)
+    endfor
+    assert_equal([(2, 3), ()], r)
+  END
+  v9.CheckSourceDefAndScriptSuccess(lines)
+enddef
+
 " Test for performing an arithmetic operation on multiple variables using
 " items from a tuple
 func Test_multi_arithmetic_op_from_tuple()

src/version.c

@@ -743,6 +743,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1242,
 /**/
     1241,
 /**/

src/vim9execute.c

@@ -3583,26 +3583,26 @@ exec_unpack_tuple(ectx_T *ectx, isn_T *iptr, typval_T *tv)
 	return EXEC_DONE;
     ectx->ec_stack.ga_len += count - 1;
 
-    // Variable after semicolon gets a list with the remaining
+    // Variable after semicolon gets a tuple with the remaining
     // items.
     if (semicolon)
     {
-	list_T	*rem_list =
-	    list_alloc_with_items(TUPLE_LEN(tuple) - count + 1);
+	tuple_T	*rem_tuple =
+	    tuple_alloc_with_items(TUPLE_LEN(tuple) - count + 1);
 
-	if (rem_list == NULL)
+	if (rem_tuple == NULL)
 	    return EXEC_DONE;
 	tv = STACK_TV_BOT(-count);
-	tv->v_type = VAR_LIST;
-	tv->vval.v_list = rem_list;
-	++rem_list->lv_refcount;
+	tv->v_type = VAR_TUPLE;
+	tv->vval.v_tuple = rem_tuple;
+	++rem_tuple->tv_refcount;
 	tv->v_lock = 0;
 	for (i = count - 1; i < TUPLE_LEN(tuple); ++i)
 	{
 	    typval_T tvcopy;
 
 	    copy_tv(TUPLE_ITEM(tuple, i), &tvcopy);
-	    list_set_item(rem_list, i - (count - 1), &tvcopy);
+	    tuple_set_item(rem_tuple, i - (count - 1), &tvcopy);
 	}
 	--count;
     }