Version of OpenTTD

93a6fd4
To be honest, I derived from it the content of #7328 on it (specifically bc45ebc), but those changes, in their current state, shall not have an impact. Moreover, I already experimented that on trunk versions too.

Output of -d driver=1 (added on @nielsmh request)

dbg: [driver] Successfully loaded blitter '32bpp-anim'
dbg: [driver] SDL: using mode 1920x921x32
dbg: [driver] SDL: using driver 'x11'
dbg: [driver] Successfully probed video driver 'sdl'
dbg: [driver] Successfully probed sound driver 'sdl'
dbg: [driver] Successfully probed music driver 'extmidi'
dbg: [driver] Successfully loaded blitter '32bpp-sse2-anim'
dbg: [driver] SDL: using mode 1920x921x32
dbg: [driver] SDL: using threads
dbg: [driver] extmidi: set volume not implemented

OS information (added on @nielsmh request)

Linux 4.9.0-8-amd64 #1 SMP Debian 4.9.144-3.1 (2019-02-19) x86_64 GNU/Linux

Expected result

No hang

Actual result

Sometimes the game freezes.
After having done a strace on the last occurrence, it gave:

futex(0x7f72103c49d0, FUTEX_WAIT, 4337, NULL

Steps to reproduce

Load a game (does not seem to be dependent on the type), and use the Exit GUI menu option.
On clicking on Yes in the popup window which appears, the game might hang.

I do not have any idea about specific conditions the game state must be in.