Crashes in SimpleShapedText

[dave96]

I’ve got reports from a user experiencing crashes in SimpleShapedText which I can’t replicate. They’re on an M2 Mac same as me and as I’m symbolicating with atos, I don’t know the problematic string.

juce::detail::Shaper::getChunksUpToNextSafeBreak(long long) (in Waveform 13) (allocator.h:0)
juce::detail::Shaper::getChunksUpToNextSafeBreak(long long) (in Waveform 13) (juce_SimpleShapedText.cpp:1018)
juce::detail::SimpleShapedText::SimpleShapedText(juce::String const*, juce::detail::ShapedTextOptions const&) (in Waveform 13) (juce_SimpleShapedText.cpp:118)
juce::detail::ShapedText::Impl* std::__1::construct_at[abi:fe180100]<juce::detail::ShapedText::Impl, juce::String, juce::detail::ShapedTextOptions, juce::detail::ShapedText::Impl*>(juce::detail::ShapedText::Impl*, juce::String&&, juce::detail::ShapedTextOptions&&) (in Waveform 13) (construct_at.h:41)
juce::detail::ShapedText::ShapedText(juce::String, juce::detail::ShapedTextOptions) (in Waveform 13) (juce_ShapedText.cpp:160)
juce::GlyphArrangement::addCurtailedLineOfText(juce::Font const&, juce::String const&, float, float, float, bool) (in Waveform 13) (juce_GlyphArrangement.cpp:216)
juce::GlyphArrangement::getStringBounds(juce::Font const&, juce::StringRef) (in Waveform 13) (juce_GlyphArrangement.h:322)

Has anyone else seen anything similar or understand where this could be going wrong?
Or even has any idea how to replicate?
Thanks.

[attila]

Spurred by this thread, we did some fuzzing tests with asan and found two crashes. One of them produced a stack trace very similar to the one you shared, so here’s hoping that the underlying issue for your crash is also fixed.

ShapedText: Fix crash caused by failing to find a fallback font for all codepoints

[dave96]

Thanks! That does look like it could be it.
I’ll do a build to send to the user and let you know if it worked.

[dave96]

Sounds like this does work for my user so many thanks for this!

I was going to try some fuzzing but never got around to it.
Did you just do it using juce::Random or a fuzzing framework?

[attila]

Yes, just juce::Random making random Unicode codepoint sequences, and feeding it into ShapedText.

[DKDiveDude]

Yep all of a sudden after upgrading to Juce 8.07 I am getting the same thing;

Ok here is something new to Juce 8.07. I’m now suddenly getting an error in juce_SimpleShapedText.cpp, caused by hovering over a knob with the following tooltip text, I even edited it down to only a few characters;

"typeSwitch.setTooltip(“Waveshaper Type\n\n\34 wave shaping algorithms”);"

Why will it not parse the above text correctly? I never had any problem with this, unchanged since Juce 5!

See screenshot of error;