ossia / score / 32543594105

38%

Build Type

push

github

Committed by jcelerier

Commit Message

plugins: stop the CLAP and LV2 cache keys returning a dangling builder

score aborts at startup with std::bad_alloc whenever the CLAP plug-in
cache is non-empty:

  qTerminate
  QStringBuilder<QStringBuilder<QString, char[2]>, QString>::convertTo<QString>()
  Media::deduplicate<Clap::PluginInfo, ...>
  Clap::ApplicationPlugin::initialize()
  score::GUIApplicationInterface::loadPluginData

The cache key was

  [](const PluginInfo& i) { return i.path + "|" + i.id; }

We compile with QT_USE_QSTRINGBUILDER (ScoreTargetSetup.cmake:76), so
operator+ builds a lazy expression template rather than a QString. With
a deduced return type the lambda hands back
QStringBuilder<QStringBuilder<QString, char[2]>, QString>, and the outer
node holds a *reference* to the inner one -- a temporary that dies at
the end of the return statement. convertTo<QString>() then reads a
garbage length out of freed memory and asks for an allocation that
throws.

LV2 has the same key shape. VST and VST3 return a plain QString member
and were never affected.

Reproduced and fixed against a real cache of 16 CLAP entries: before,
every run of ossia-score and of the AJA test harness aborted in
loadPluginData; after, both start and enumerate normally. The whole AJA
validation campaign had to run under SCORE_DISABLE_AUDIOPLUGINS=1 to get
past it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014rZgzE8JjWvHDtaVUhxpLE

Coverage Stats

3 of 4 new or added lines in 2 files covered. (75.0%)

6 existing lines in 1 file now uncovered.

44511 of 214028 relevant lines covered (20.8%)

5792.41 hits per line