Merge pull request #7818 from kenjis/fix-set_checkbox

fix: `set_checkbox()` checks unchecked checkbox

Author: kenjis

system/Helpers/form_helper.php

@@ -629,8 +629,11 @@ function set_checkbox(string $field, string $value = '', bool $default = false):
             return '';
         }
 
+        $session     = Services::session();
+        $hasOldInput = $session->has('_ci_old_input');
+
         // Unchecked checkbox and radio inputs are not even submitted by browsers ...
-        if ((string) $input === '0' || ! empty($request->getPost()) || ! empty(old($field))) {
+        if ((string) $input === '0' || ! empty($request->getPost()) || $hasOldInput) {
             return ($input === $value) ? ' checked="checked"' : '';
         }
 

tests/system/Helpers/FormHelperTest.php

@@ -867,6 +867,29 @@ public function testSetCheckboxWithValueZero(): void
         $this->assertSame(' checked="checked"', set_checkbox('foo', '0', true));
     }
 
+    /**
+     * @see https://github.com/codeigniter4/CodeIgniter4/issues/7814
+     */
+    public function testSetCheckboxWithUnchecked(): void
+    {
+        $_SESSION = [
+            '_ci_old_input' => [
+                'post' => [
+                ],
+            ],
+        ];
+
+        $this->assertSame(
+            '',
+            set_checkbox('fruit', 'apple', true)
+        );
+
+        $this->assertSame(
+            '',
+            set_checkbox('fruit', 'apple')
+        );
+    }
+
     /**
      * @runInSeparateProcess
      * @preserveGlobalState disabled