From: zeertzjq <zeertzjq@outlook.com>
Date: Sat, 18 Jul 2026 13:57:04 +0000 (+0000)
Subject: patch 9.2.0794: extend() and extendnew() don't handle NULL expr2 properly
X-Git-Tag: v9.2.0794^0
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=e397c82a04fc86ef9266e494a8c2ccc199159a93;p=thirdparty%2Fvim.git

patch 9.2.0794: extend() and extendnew() don't handle NULL expr2 properly

Problem:  extend() and extendnew() don't handle NULL expr2 properly
          (Mao-Yining)
Solution: Still set the return value when expr2 is NULL (zeertzjq).

fixes:  #20758
closes: #20759

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
---

diff --git a/src/dict.c b/src/dict.c
index 1106395085..ac1fb3841b 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -1335,9 +1335,6 @@ dict_extend_func(
 	emsg(_(e_cannot_extend_null_dict));
 	return;
     }
-    d2 = argvars[1].vval.v_dict;
-    if (d2 == NULL)
-	return;
 
     if (!is_new && value_check_lock(d1->dv_lock, arg_errmsg, TRUE))
 	return;
@@ -1349,6 +1346,10 @@ dict_extend_func(
 	    return;
     }
 
+    d2 = argvars[1].vval.v_dict;
+    if (d2 == NULL)
+	goto theend;
+
     // Check the third argument.
     if (argvars[2].v_type != VAR_UNKNOWN)
     {
@@ -1384,6 +1385,7 @@ dict_extend_func(
     }
     dict_extend(d1, d2, action, func_name);
 
+theend:
     if (is_new)
     {
 	rettv->v_type = VAR_DICT;
diff --git a/src/list.c b/src/list.c
index 3074bb93f2..e400cb096f 100644
--- a/src/list.c
+++ b/src/list.c
@@ -3014,9 +3014,7 @@ list_extend_func(
 	emsg(_(e_cannot_extend_null_list));
 	return;
     }
-    l2 = argvars[1].vval.v_list;
-    if ((is_new || !value_check_lock(l1->lv_lock, arg_errmsg, TRUE))
-								 && l2 != NULL)
+    if (is_new || !value_check_lock(l1->lv_lock, arg_errmsg, TRUE))
     {
 	if (is_new)
 	{
@@ -3025,6 +3023,10 @@ list_extend_func(
 		return;
 	}
 
+	l2 = argvars[1].vval.v_list;
+	if (l2 == NULL)
+	    goto theend;
+
 	if (argvars[2].v_type != VAR_UNKNOWN)
 	{
 	    before = (long)tv_get_number_chk(&argvars[2], &error);
@@ -3049,6 +3051,7 @@ list_extend_func(
 	    goto cleanup;
 	list_extend(l1, l2, item);
 
+theend:
 	if (is_new)
 	{
 	    rettv->v_type = VAR_LIST;
diff --git a/src/testdir/test_listdict.vim b/src/testdir/test_listdict.vim
index 316e3614fc..31b5f268d7 100644
--- a/src/testdir/test_listdict.vim
+++ b/src/testdir/test_listdict.vim
@@ -1217,7 +1217,12 @@ func Test_listdict_extend()
 
       LET l = [1, 2, 3]
       call extend(l, [4, 5, 6], -3)
-      call assert_equal([4, 5, 6, 1, 2,  3], l)
+      call assert_equal([4, 5, 6, 1, 2, 3], l)
+
+      LET l = [1, 2, 3]
+      call assert_equal([1, 2, 3], l->extend([]))
+      call assert_equal([1, 2, 3], l->extend(test_null_list()))
+      call assert_equal([1, 2, 3], l)
   END
   call v9.CheckLegacyAndVim9Success(lines)
 
@@ -1245,6 +1250,11 @@ func Test_listdict_extend()
       LET d = {'a': 'A', 'b': 9}
       call extend(d, {'b': 0, 'c': 'C'}, "keep")
       call assert_equal({'a': 'A', 'b': 9, 'c': 'C'}, d)
+
+      LET d = {'a': 'A', 'b': 9}
+      call assert_equal({'a': 'A', 'b': 9}, d->extend({}))
+      call assert_equal({'a': 'A', 'b': 9}, d->extend(test_null_dict()))
+      call assert_equal({'a': 'A', 'b': 9}, d)
   END
   call v9.CheckLegacyAndVim9Success(lines)
 
@@ -1286,6 +1296,11 @@ func Test_listdict_extendnew()
   call assert_equal([1, 2, 3], l)
   lockvar l
   call assert_equal([1, 2, 3, 4, 5], extendnew(l, [4, 5]))
+  let l2 = extendnew(l, test_null_list())
+  call assert_equal([1, 2, 3], l2)
+  let l2 += [4]
+  call assert_equal([1, 2, 3, 4], l2)
+  call assert_equal([1, 2, 3], l)
 
   " Test extendnew() with dictionaries.
   let d = {'a': {'b': 'B'}}
@@ -1293,6 +1308,11 @@ func Test_listdict_extendnew()
   call assert_equal({'a': {'b': 'B'}}, d)
   lockvar d
   call assert_equal({'a': {'b': 'B'}, 'c': 'cc'}, extendnew(d, {'c': 'cc'}))
+  let d2 = extendnew(d, test_null_dict())
+  call assert_equal({'a': {'b': 'B'}}, d2)
+  let d2['c'] = 'C'
+  call assert_equal({'a': {'b': 'B'}, 'c': 'C'}, d2)
+  call assert_equal({'a': {'b': 'B'}}, d)
 endfunc
 
 func s:check_scope_dict(x, fixed)
diff --git a/src/version.c b/src/version.c
index 4e3ca0b5e7..d2d3c45dcc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -759,6 +759,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    794,
 /**/
     793,
 /**/