Fixes #6345 - Using square brackets in text modules.

Approved-by: Dusan Vuckovic <dv@zammad.com>

app/assets/javascripts/app/lib/base/jquery.textmodule.js

@@ -565,8 +565,8 @@
   }
 
   Collection.renderResults = function(textmodule, term) {
-    var reg     = new RegExp(term, 'i')
-    var regFull = new RegExp('\\b' + term + '\\b', 'i')
+    var reg     = new RegExp(escapeRegExp(term), 'i')
+    var regFull = new RegExp('\\b' + escapeRegExp(term) + '\\b', 'i')
     var result  = textmodule.collection.filter(function(item) {
       return matchItemWithRegExp(item, reg) && !matchItemWithRegExp(item, regFull)
     })

public/assets/tests/qunit/text_module.js

@@ -129,3 +129,93 @@ QUnit.test('test text module behaviour with group_ids', assert => {
   assert.equal(currentCollection[1].id, 3)
 
 });
+
+// Regex characters in text module names must be matched literally, not
+//   interpreted as a regular expression (issue #6345).
+QUnit.test('test text module search with regex characters in the name', assert => {
+  App.User.refresh([{
+    "login": "hh@example.com",
+    "firstname": "Harald",
+    "lastname": "Habebe",
+    "email": "hh@example.com",
+    "role_ids": [ 1, 2, 4 ],
+    "group_ids": [ 1, 2 ],
+    "active": true,
+    "id": 6
+  }]);
+  App.Session.set(6)
+
+  // mock user methods
+  App.Session.get().allGroupIds = () => ['1','2']
+  App.Session.get().permission = () => true
+
+  App.TextModule.refresh([
+    {
+      id:       10,
+      name:     '[category] Some product',
+      keywords: 'bracketed',
+      content:  'content10',
+      active:   true,
+    },
+    {
+      id:       11,
+      name:     '[product] Some category',
+      keywords: 'bracketed',
+      content:  'content11',
+      active:   true,
+    },
+  ], { clear: true })
+
+  $('body').append('<div id="text-module-regex-chars"><div contenteditable="true"></div></div>')
+
+  var el = $('#text-module-regex-chars [contenteditable]')
+
+  var textModule = new App.WidgetTextModule({
+    el:      el,
+    data:    {
+      user:   App.Session.get(),
+      config: App.Config.all(),
+    },
+    taskKey: 'test-regex-chars',
+  })
+
+  var plugin = el.data('plugin_textmodule')
+
+  // Run the search the way a keystroke would: the buffer holds the trigger
+  //   plus the term the user typed after it.
+  var search = (buffer) => {
+    plugin.buffer = buffer
+    plugin.result(plugin.findTrigger(buffer))
+
+    return plugin.$widget.find('ul > li').map(function() {
+      return $(this).attr('data-id')
+    }).get().sort()
+  }
+
+  try {
+    // An unterminated character class must not blow up the search.
+    assert.deepEqual(search('::[category'), ['10'], 'unterminated bracket matches literally')
+
+    // A complete character class must not match every entry.
+    assert.deepEqual(search('::[category]'), ['10'], 'complete bracket matches literally')
+
+    // Other regex metacharacters are literal too.
+    assert.deepEqual(search('::product) Some'), [], 'unbalanced parenthesis matches nothing')
+
+    // The term is taken literally, so the former escaping workaround now
+    //   searches for a backslash and finds nothing.
+    assert.deepEqual(search('::\\[category'), [], 'backslash is no longer an escape')
+
+    // Terms without regex characters keep working.
+    assert.deepEqual(search('::bracketed'), ['10', '11'], 'keyword matches both')
+
+    assert.deepEqual(search('::category'), ['10', '11'], 'plain term matches both')
+  }
+  finally {
+    // Keep the fixture self-contained: an assertion that throws must not leave
+    //   a detached element subscribed to the text module collection.
+    textModule.releaseController()
+    textModule.release()
+    $('#text-module-regex-chars').remove()
+  }
+});