MDL-45221 admin: configexecutable admin settings should only accept files

lib/adminlib.php

@@ -2352,7 +2352,7 @@ class admin_setting_configexecutable extends admin_setting_configfile {
         $default = $this->get_defaultsetting();
 
         if ($data) {
-            if (file_exists($data) and is_executable($data)) {
+            if (file_exists($data) and !is_dir($data) and is_executable($data)) {
                 $executable = '<span class="pathok">&#x2714;</span>';
             } else {
                 $executable = '<span class="patherror">&#x2718;</span>';

lib/tests/admintree_test.php

@@ -111,6 +111,36 @@ class core_admintree_testcase extends advanced_testcase {
         $tree->add('root', new admin_category('bar', 'Bar'), '');
     }
 
+    /**
+     * Testing whether a configexecutable setting is executable.
+     */
+    public function test_admin_setting_configexecutable() {
+        global $CFG;
+        $this->resetAfterTest();
+
+        $executable = new admin_setting_configexecutable('test1', 'Text 1', 'Help Path', '');
+
+        // Check for an invalid path.
+        $result = $executable->output_html($CFG->dirroot . '/lib/tests/other/file_does_not_exist');
+        $this->assertRegexp('/class="patherror"/', $result);
+
+        // Check for a directory.
+        $result = $executable->output_html($CFG->dirroot);
+        $this->assertRegexp('/class="patherror"/', $result);
+
+        // Check for a file which is not executable.
+        $result = $executable->output_html($CFG->dirroot . '/config.php');
+        $this->assertRegexp('/class="patherror"/', $result);
+
+        // Check for an executable file.
+        $result = $executable->output_html($CFG->dirroot . '/lib/tests/other/executable.php');
+        $this->assertRegexp('/class="pathok"/', $result);
+
+        // Check for no file specified.
+        $result = $executable->output_html('');
+        $this->assertRegexp('/name="s__test1" value=""/', $result);
+    }
+
     /**
      * Saving of values.
      */