autocomplete: Exclude user from autocomplete popup if deactivated

Fixes #451

Author: Khader-1

lib/model/autocomplete.dart

@@ -289,6 +289,8 @@ class MentionAutocompleteQuery {
     // TODO(#236) test email too, not just name
     // TODO(#237) test with diacritics stripped, where appropriate
 
+    if (!user.isActive) return false;
+
     return _testName(user, cache);
   }
 

test/model/autocomplete_test.dart

@@ -343,6 +343,11 @@ void main() {
       doCheck('F Full', eg.user(fullName: 'Full Name Four Words'), false);
       doCheck('Four F', eg.user(fullName: 'Full Name Four Words'), false);
     });
+
+    test('user is always excluded when not active regardless of other criteria', () {
+      doCheck('Full Name', eg.user(fullName: 'Full Name', isActive: false), false);
+    });
+
   });
 
 }