frosch opened the ticket and wrote:

When changing NewGRF in game, the blitter might be switched.

Switching of the blitter is triggered during the processing of the mouse click.
However, _draw_mutex is locked during VideoDriver_SDL::PollEvent. VideoDriver_SDL::ChangeResolution then tries to lock it again.

# 6 0x00007f648769a621 in *__GI___assert_fail (assertion=0xe0bf79 "err == 0", file=, line=122, function=0xe0c0e0 "virtual void ThreadMutex_pthread::BeginCritical()") at assert.c:81
# 7 0x0000000000a22072 in ThreadMutex_pthread::BeginCritical (this=0x36014f0) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/thread/thread_pthread.cpp:122
# 8 0x0000000000a85639 in VideoDriver_SDL::ChangeResolution (this=0x35eba00, w=1826, h=936) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/video/sdl_v.cpp:820
# 9 0x0000000000a85729 in VideoDriver_SDL::AfterBlitterChange (this=0x35eba00) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/video/sdl_v.cpp:840
# 10 0x00000000007b442b in SwitchNewGRFBlitter () at /home/frosch/daten/ottd/trunk/hgtrunk8/src/gfxinit.cpp:245
# 11 0x00000000007b44bc in GfxLoadSprites () at /home/frosch/daten/ottd/trunk/hgtrunk8/src/gfxinit.cpp:258
# 12 0x0000000000951af4 in ReloadNewGRFData () at /home/frosch/daten/ottd/trunk/hgtrunk8/src/saveload/afterload.cpp:2864
# 13 0x000000000088c5c5 in NewGRFConfirmationCallback (w=0x3be8970, confirmed=true) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/newgrf_gui.cpp:1904
# 14 0x00000000008186bb in QueryWindow::OnClick (this=0x50ae430, pt=..., widget=3, click_count=1) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/misc_gui.cpp:1121
# 15 0x0000000000aab9a1 in DispatchLeftClickEvent (w=0x50ae430, x=162, y=168, click_count=1) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/window.cpp:738
# 16 0x0000000000ab0a3f in MouseLoop (click=MC_LEFT, mousewheel=0) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/window.cpp:2827
# 17 0x0000000000ab0e2b in HandleMouseEvents () at /home/frosch/daten/ottd/trunk/hgtrunk8/src/window.cpp:2916
# 18 0x0000000000a84e34 in VideoDriver_SDL::PollEvent (this=0x35eba00) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/video/sdl_v.cpp:584
# 19 0x0000000000a8523d in VideoDriver_SDL::MainLoop (this=0x35eba00) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/video/sdl_v.cpp:720
# 20 0x00000000008bccc7 in openttd_main (argc=1, argv=0x7fff96f42788) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/openttd.cpp:857
# 21 0x00000000008d4516 in main (argc=1, argv=0x7fff96f42788) at /home/frosch/daten/ottd/trunk/hgtrunk8/src/os/unix/unix.cpp:275

Reported version: trunk
Operating system: Linux

This issue was imported from FlySpray: https://bugs.openttd.org/task/5787