https://bugs.kde.org/show_bug.cgi?id=507547
--- Comment #2 from Matthias Grimrath <kdeb...@guter-grimmiger-rat.de> --- (In reply to Mladen Milinkovic, Max from comment #1) > I would appreciate exact message that is written - it should says something > like: ASSERT: "m_ref != nullptr" in file /home/matthias/build/subtitlecomposer-upstream/src/core/subtitleline.cpp, line 230 Build from this source: branch 'master' of https://invent.kde.org/multimedia/subtitlecomposer commit a5a9b4916787f3b5263945cd63840fcb8e5a43cf (HEAD -> master, origin/master, origin/HEAD) Author: l10n daemon script <scri...@kde.org> Date: Wed Jul 16 03:01:03 2025 +0000 GIT_SILENT Sync po/docbooks with svn > According to C++ specs? This is the code in question: Q_ASSERT(m_ref != nullptr); Q_ASSERT(m_ref->m_obj == this); const int index = m_ref - m_subtitle->m_lines.constData(); if(index < 0 || index >= m_subtitle->count()) { ... So if 'm_ref' is NULL, 'index' contains garbage. Maybe it's not undefined by specification - I'm no language lawyer :) - but nevertheless I think it is not desirable. In practice though the bogus value in 'index' probably triggers the following 'if' clause, so the still-in-place work-around code amends the situation. > > SOFTWARE/OS VERSIONS > It shouldn't, but please: > - What OS and version are you using? Artix Linux, Arch derivative, a rolling release distribution > - What compiler and version are you using? Is it one shipped with that > OS/distribution? yes, from the distribution $ g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/15.1.1/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --enable-languages=ada,c,c++,d,fortran,go,lto,m2,objc,obj-c++,rust,cobol --enable-bootstrap --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://gitea.artixlinux.org/packages/gcc/issues --with-build-config=bootstrap-lto --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-libstdcxx-backtrace --enable-link-serialization=1 --enable-linker-build-id --enable-lto --enable-multilib --enable-plugin --enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch --disable-werror Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 15.1.1 20250425 (GCC) > - What Qt version are you using? Is it one shipped with that OS/distribution? Yes, pacman says 'local/qt6-base 6.9.0-1 (qt6)' > If the assert says: > ASSERT: "m_ref != nullptr" in file ........./subtitleline.cpp, line 230 > your compiler is optimizing too much away and not calling object > constructors when resizing vectors. > > I saw this happen in some old Linux Mint build worker, but was unable to > reproduce it anywhere. In my experience C++ (not only) template semantics are very tricky. So I wouldn't be surprised if the language spec allows that constructors in this case here (Qt Linesmodel) may not be called as one would expect. For this same reason (tricky semantics) I try to avoid using own non-trivial classes with STL containers. -- You are receiving this mail because: You are watching all bug changes.
