eca1271bbc
The new general convex path shadow code was checking for duplicate vertices without actually checking if the vectors contained any vertices. Thus, <vector>.back() was being called on empty vectors, which is bad. This led to a crash in G3 as their code is being run with a vector implementation that protects against this, but apparently we do not have such a vector implementation in our local building and testing. No tests because this covered by existing test cases and a new FML_DCHECK. <!-- Thanks for filing a pull request! Reviewers are typically assigned within a week of filing a request. To learn more about code review, see our documentation on Tree Hygiene: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md --> Fixes https://github.com/flutter/flutter/issues/180827 Impacted users: Any user who uses shadows (pretty much every Flutter app) on a platform that has address sanitization built into its `std::vector` implementation, if they use Impeller (always used on iOS and the default on Android) Impact Description: Every shadow render operation in Impeller backend will access `back()` on an empty `std::vector` which will crash immediately if the vector is using sanitization on that platform. Workaround: Potentially look into disabling address sanitization? On platforms that still support Skia, it can be used as a workaround, but that is not an option on iOS Risk: The fix was obvious and non-controversial. Test Coverage: Existing tests cover this case really well and there is now an FML_DCHECK (engine assert) to check if we trigger the condition under testing. Validation: The original issue indicates an app that will trigger the sanitization crash, but only in G3. None of the platforms we support directly through flutter perform this sanitization. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.
Flutter is Google's SDK for crafting beautiful, fast user experiences for mobile, web, and desktop from a single codebase. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source.
Documentation
For release and other announcements, join the flutter-announce mailing list. Our documentation also tracks breaking changes across releases.
Terms of service
The Flutter tool may occasionally download resources from Google servers. By downloading or using the Flutter SDK, you agree to the Google Terms of Service: https://policies.google.com/terms
For example, when installed from GitHub (as opposed to from a prepackaged
archive), the Flutter tool will download the Dart SDK from Google servers
immediately when first run, as it is used to execute the flutter tool itself.
This will also occur when Flutter is upgraded (e.g. by running the flutter upgrade command).
About Flutter
We think Flutter will help you create beautiful, fast apps, with a productive, extensible and open development model, whether you're targeting iOS or Android, web, Windows, macOS, Linux or embedding it as the UI toolkit for a platform of your choice.
Beautiful user experiences
We want to enable designers to deliver their full creative vision without being forced to water it down due to limitations of the underlying framework. Flutter's layered architecture gives you control over every pixel on the screen and its powerful compositing capabilities let you overlay and animate graphics, video, text, and controls without limitation. Flutter includes a full set of widgets that deliver pixel-perfect experiences whether you're building for iOS (Cupertino) or other platforms (Material), along with support for customizing or creating entirely new visual components.
Fast results
Flutter is fast. It's powered by hardware-accelerated 2D graphics libraries like Skia (which underpins Chrome and Android) and Impeller. We architected Flutter to support glitch-free, jank-free graphics at the native speed of your device.
Flutter code is powered by the world-class Dart programming language, which enables compilation to 32-bit and 64-bit ARM machine code for iOS and Android, JavaScript and WebAssembly for the web, as well as Intel x64 and ARM for desktop devices.
Productive development
Flutter offers stateful hot reload, allowing you to make changes to your code and see the results instantly without restarting your app or losing its state.
Extensible and open model
Flutter works with any development tool (or none at all), and also includes editor plug-ins for both Visual Studio Code and IntelliJ / Android Studio. Flutter provides tens of thousands of packages to speed your development, regardless of your target platform. And accessing other native code is easy, with support for both FFI (on Android, on iOS, on macOS, and on Windows) as well as platform-specific APIs.
Flutter is a fully open-source project, and we welcome contributions. Information on how to get started can be found in our contributor guide.