commit aa210a3aeccc33c6051978017959126b037f94af
author Bram Moolenaar <Bram@vim.org> Sat Jan 02 15:41:03 2021 +0100
committer Bram Moolenaar <Bram@vim.org> Sat Jan 02 15:41:03 2021 +0100
tree 29c2f91c51dc55a52e427f89643ae4b9c4c56c58
parent 3e0107ea16349b354e0e9712e95b09ef019e99e5

patch 8.2.2272: Vim9: extend() can violate the type of a variable

Problem:    Vim9: extend() can violate the type of a variable.
Solution:   Add the type to the dictionary or list and check items against it.
            (closes #7593)

src/list.c

diff --git a/src/list.c b/src/list.c
index 1c41f07..56ee5a5 100644
--- a/src/list.c
+++ b/src/list.c
@@ -270,6 +270,7 @@
     if (l->lv_used_next != NULL)
 	l->lv_used_next->lv_used_prev = l->lv_used_prev;
 
+    free_type(l->lv_type);
     vim_free(l);
 }
 
@@ -689,13 +690,17 @@
 /*
  * Insert typval_T "tv" in list "l" before "item".
  * If "item" is NULL append at the end.
- * Return FAIL when out of memory.
+ * Return FAIL when out of memory or the type is wrong.
  */
     int
 list_insert_tv(list_T *l, typval_T *tv, listitem_T *item)
 {
-    listitem_T	*ni = listitem_alloc();
+    listitem_T	*ni;
 
+    if (l->lv_type != NULL && l->lv_type->tt_member != NULL
+		    && check_typval_type(l->lv_type->tt_member, tv, 0) == FAIL)
+	return FAIL;
+    ni = listitem_alloc();
     if (ni == NULL)
 	return FAIL;
     copy_tv(tv, &ni->li_tv);