Never trust external content for FString #9145
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When creating an FString for the first time, we should never trust that the incoming byte[] or ByteList are now ours to own. The caller might still have a reference to them that they continue to modify, resulting in a zombie FString that can't be found or that has incorrect contents. This came up while trying to implement the "fake string" optimization for uncached headers in puma/puma#3838. Holding a reference to a RubyString and its ByteList that could be updated in-place and then used to caches new headers led to those cached FStrings being modified directly.
headius
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Pushed a test after merge in 1cb0236 |
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When creating an FString for the first time, we should never trust that the incoming byte[] or ByteList are now ours to own. The caller might still have a reference to them that they continue to modify, resulting in a zombie FString that can't be found or that has incorrect contents.
This came up while trying to implement the "fake string" optimization for uncached headers in puma/puma#3838. Holding a reference to a RubyString and its ByteList that could be updated in-place and then used to caches new headers led to those cached FStrings being modified directly.