wx: Fix array reading out of bounds, and potential memory leaks

[dgud]

Issues reported in the excellent blog post at
https://pvs-studio.com/en/blog/posts/cpp/1305/

[github-actions]

CT Test Results

  2 files   17 suites   4m 24s ⏱️
158 tests 151 ✅ 7 💤 0 ❌
174 runs  167 ✅ 7 💤 0 ❌

Results for commit aa16380.

♻️ This comment has been updated with latest results.

To speed up review, make sure that you have read Contributing to Erlang/OTP and that all checks pass.

See the TESTING and DEVELOPMENT HowTo guides for details about how to run test locally.

Artifacts

• Complete CT logs (Download Logs)
• HTML Documentation (Download HTML Docs)
• Windows Installer

// Erlang/OTP Github Action Bot

[kvakvs]

I just checked wxImage constructors (base of EwxImage) documentation and it says that in case when the 5th parameter static_data is having default value false, wx will take ownership of the data and for that it must be allocated by malloc. Such is the way they do things in the C kingdom. So i guess the change is sufficient, but brittle (till the generated code changes next time again).

(since C++ is already in this file, can use C++'s auto-memory management facilities) Alternative would be for Ewximage to own its memory: use a smart pointer to allocate and own pixels data, and then any kind of destruction operation would automatically free it. That would look beautiful but will also increase the change scope.

[kvakvs]

I wholeheartedly support a bigger review of memory management patterns in generated and hand-written code in the future. Would love to join :)