Fix crash with Nvidia 331.38 drivers on Linux

[tronical]

glDeleteFramebuffers appears to crash when called with zero FBOs to
delete.

[springmeyer]

Thanks for this report. Can you share what linux version you saw this on and the backtrace? I'd like to delve deeper to see if I can replicate.

[tronical]

Sure. Here are some more details:

From glxinfo: OpenGL core profile version string: 3.3.0 NVIDIA 331.38
gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1)
This is on x86-64.

With a debug build of mapbox-gl I get the following debug output and back trace:
Starting program: /home/simon/src/mapbox-gl-native/build/Debug/mapbox-gl
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff1fa6700 (LWP 15008)]
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.92616ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.6748ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.72836ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.73084ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.65924ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.61612ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 2.00356ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.86144ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.6242ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.5998ms
Shader compile log:
Shader compile log:
Program link log:
Program validate log:
shader compilation: 0.6336ms
painter setup: 13.3732ms
[New Thread 0x7ffff158d700 (LWP 15009)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7ffff1fa6700 (LWP 15008)]
0x00007ffff3d59f9c in ?? () from /usr/lib/nvidia-331-updates/libnvidia-glcore.so.331.38
(gdb) bt
#0 0x00007ffff3d59f9c in ?? () from /usr/lib/nvidia-331-updates/libnvidia-glcore.so.331.38
#1 0x00007ffff3d1371e in ?? () from /usr/lib/nvidia-331-updates/libnvidia-glcore.so.331.38
#2 0x0000000000483172 in llmr::Painter::clearFramebuffers (this=0x7fffffffda08) at ../../src/renderer/painter_framebuffers.cpp:25
#3 0x0000000000431e73 in llmr::Map::prepare (this=0x7fffffffd880) at ../../src/map/map.cpp:460
#4 0x000000000043004b in llmr::Map::run (this=0x7fffffffd880) at ../../src/map/map.cpp:94
#5 0x000000000042fc5f in llmr::Map::__lambda5::operator() (__closure=0x0, arg=0x7fffffffd880) at ../../src/map/map.cpp:64
#6 0x000000000042fca2 in llmr::Map::__lambda5::_FUN (arg=0x7fffffffd880) at ../../src/map/map.cpp:65
#7 0x00000000005cf957 in uv.thread_start ()
#8 0x00007ffff77a3182 in start_thread (arg=0x7ffff1fa6700) at pthread_create.c:312
#9 0x00007ffff5c1a30d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
(gdb) frame 2
#2 0x0000000000483172 in llmr::Painter::clearFramebuffers (this=0x7fffffffda08) at ../../src/renderer/painter_framebuffers.cpp:25
25 glDeleteFramebuffers((int)fbos.size(), fbos.data());
(gdb) p fbos.size()
$1 = 0
(gdb) p fbos.data()
$2 = (unsigned int *) 0x0
(gdb) list
20 if (fbo_depth_stencil != 0) {
21 glDeleteRenderbuffers(1, &fbo_depth_stencil);
22 fbo_depth_stencil = 0;
23 }
24
25 glDeleteFramebuffers((int)fbos.size(), fbos.data());
26 fbos.clear();
27 }
28
29 void Painter::bindFramebuffer() {

[preet]

Ran into the same issue, just wanted to confirm the patch fixed the problem for me:
(gdb) backtrace
#0 0x00007ffff2b0bf9c in ?? () from /usr/lib/libnvidia-glcore.so.331.38
#1 0x00007ffff2ac571e in ?? () from /usr/lib/libnvidia-glcore.so.331.38
#2 0x00000000004527cb in llmr::Painter::clearFramebuffers() ()
#3 0x0000000000424ad5 in llmr::Map::prepare() ()
#4 0x00000000004268f1 in llmr::Map::start()::{lambda(void_)#1}::FUN(void) ()
#5 0x00000000004e5957 in uv.thread_start ()
#6 0x00007ffff74a80a2 in start_thread () from /usr/lib/libpthread.so.0
#7 0x00007ffff4394d1d in clone () from /usr/lib/libc.so.6

[jfirebaugh]

No longer applicable; glDeleteFramebuffers is never called with variable size now.