Inline/Block Code MfM can cause visual bug

[DenialOfIntelligence]

💡 Summary

For example the text "`-<a`" causes this visual bug where instead of showing the text it shows a large gray box:

I have experimented a bit and here is what I have found to be required to trigger this:

• The code element must be using the default highlighter
• The text must be at the end in the code element
• The first part can be of any length but must be only of these characters -_!%^&*=+[({>,/?~;: and spaces
• The second part can only be < and must have an odd amount of characters
• The last part can be of any length but must only use a-z (any case), 0-9, -, _ and .

🥰 Expected Behavior

I can see the text.

🤬 Actual Behavior

As explained previously the gray box appears. When occurring the terminal outputs:

flutter: RangeError (index): Invalid value: Not in inclusive range 0..2: 3
flutter: #0      _StringBase.[] (dart:core-patch/string_patch.dart:274)
flutter: #1      language_javascript_contains_0_contains_0_variants_0_onBegin (package:highlighting/src/callbacks.dart:35)
flutter: #2      HighlightV2.highlight.doBeginMatch (package:highlighting/src/highlightv2.dart:267)
flutter: #3      HighlightV2.highlight.processLexeme (package:highlighting/src/highlightv2.dart:356)
flutter: #4      HighlightV2.highlight (package:highlighting/src/highlightv2.dart:399)
flutter: #5      HighlightView.build (package:flutter_highlighting/flutter_highlighting.dart:97)
flutter: #6      StatelessElement.build (package:flutter/src/widgets/framework.dart:5687)
flutter: #7      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5617)
flutter: #8      Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #9      ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #10     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #11     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #12     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #13     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #14     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #15     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #16     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #17     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #18     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #19     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #20     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #21     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #22     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #23     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #24     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #25     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #26     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #27     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #28     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #29     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5780)
flutter: #30     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #31     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #32     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:5771)
flutter: #33     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #34     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #35     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #36     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #37     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #38     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #39     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #40     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #41     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #42     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #43     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #44     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #45     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #46     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #47     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #48     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #49     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #50     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #51     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #52     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #53     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #54     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #55     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5780)
flutter: #56     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #57     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #58     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:5771)
flutter: #59     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #60     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #61     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #62     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #63     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #64     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #65     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #66     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #67     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #68     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #69     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #70     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #71     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #72     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #73     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #74     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #75     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #76     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #77     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #78     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #79     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #80     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #81     StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5780)
flutter: #82     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #83     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #84     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:5771)
flutter: #85     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #86     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #87     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #88     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #89     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #90     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)
flutter: #91     ComponentElement.mount (package:flutter/src/widgets/framework.dart:5593)
flutter: #92     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #93     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #94     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:6900)
flutter: #95     Element.inflateWidget (package:flutter/src/widgets/framework.dart:4468)
flutter: #96     Element.updateChild (package:flutter/src/widgets/framework.dart:3963)
flutter: #97     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5642)
flutter: #98     Element.rebuild (package:flutter/src/widgets/framework.dart:5333)
flutter: #99     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:5599)

Any time this is triggered again:

flutter: Another exception was thrown: Instance of 'DiagnosticsProperty<void>'

📝 Steps to Reproduce

1. Get a post which contains text that matches the previously stated requirements or make one yourself e.g. this post which caused me to notice this bug
2. Look at said post in aria
3. That's it you now a big gray box!

💻 Environment

* Model and OS of the device(s): Pixel 3a, Android 14; Linux Pc
* Aria: 0.15.0 Android/0.15.1 Pc
* Server URL: plasmatrap.com
* Sharkey: v2024.9.1-dev

Do you want to address this bug yourself?

• [ ] Yes, I will patch the bug myself and send a pull request

[poppingmoon]

Thank you for reporting this.

I think this is a bug from https://github.com/ahmadf45/dart-highlighting, which is used for syntax highlighting of the codes.

I am not sure how it works and I don't know what is the real cause of this bug, but the error says it is accessing a character out of range. So I forked the package and added a small change to avoid the invalid index access. With #425, `-<a` renders correctly.