Created attachment 159945 [details] Backtrace The following requires a debug LO build to trigger. Not sure if there's any other prerequisite, the assert seems to indicate some kind of font fallback handling problem (not related to the repro, since that uses Liberation Serif font). - Build LOOL, and open the sample hello-world.odt in the browser with the URL given on the console. => Repeated crashes (since LOOL tries to reload the document). The console shows the following assert: "vcl/unx/generic/gdi/freetypetextrender.cxx:166: virtual std::unique_ptr<GenericSalLayout> FreeTypeTextRenderImpl::GetTextLayout(int): Assertion `mpFreetypeFont[nFallbackLevel]' failed." Attaching backtrace. The backtrace indicates it's triggered when populating the font name box with the rendered name of the font when rendering headless. This could perhaps be reproduced purely with core in some way. This font name box and its pre-rendered contents are never shown in LOOL, btw. This is a recent regression, bisected to the following commit. Adding CC: to Caolán McNamara. https://cgit.freedesktop.org/libreoffice/core/commit/?id=2e0a32b51681fb356699b4a722f461f55a46b890 author Caolán McNamara <caolanm@redhat.com> 2020-04-07 12:21:47 +0100 committer Caolán McNamara <caolanm@redhat.com> 2020-04-21 10:19:41 +0200 weld FontNameBox
could you get a thread apply all backtrace set of backtraces, I wonder if there are other threads involved
Created attachment 159961 [details] Backtrace w thread apply all It doesn't seem so. Attaching the backtrace.
The assert seems to be tied to specific fonts, disabling the following fonts in FontManager makes it go away for me: Fira Mono, Fira Sans, Optima, TeX Gyre *, Vegur.
ah!, it then might not actually be a true regression of the identified commit. The previews are generated for all fonts in an idle now in advance. So it possible that versions prior to that commit also asserted on visiting those fontnames in the dropdown. That said, if lool is not using the previews then its presumably wasteful to generate them.
Caolán McNamara committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/commit/60fcd4427231e8c48cd3bf8307e280fd3a13a84f tdf#132424 don't generate font previews in advance for lool It will be available in 7.0.0. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Since now it doesn't crash with an assert on startup, I'm marking this fixed, and opening a new bug report with updated repro steps. Thanks for the fix, Caolán!