Created attachment 3432 [details]
Fix SDL_CreateRenderer() crash

I received a bug report that a user was seeing my app crashing randomly. We narrowed it down to likely being a display driver crash (but the app crash was not expected). When this happens, the D3D device loss triggers us to try to create a new renderer. This ends up hitting GL_CreateRenderer() after D3D9 renderer creation fails, where it tries to look up OpenGL functions with GL_LoadFunctions().

Since the display driver is recovering, we don't have a working third party OGL implementation. The stock opengl32.dll lacks some of the functions that SDL looks for in GL_LoadFunctions(). The first one that's missing is glBlendEquation() which was introduced in OGL 1.2. When we hit this one, GL_LoadFunctions() fails, causing GL_DestroyRenderer() to be called. This eventually ends up calling a null pointer when SDL tries to invoke data->glViewport() inside GL_UpdateViewport().

The attached patch avoids caling GL_DestroyRenderer() until GL_LoadFunctions() has succeeded. I've also updated the GLES2 code which also had the same bug.

0:000> .excr
rax=0000000000000438 rbx=000002cae06b16b0 rcx=0000000000000000
rdx=0000000000000438 rsi=000002cae06b16b0 rdi=000002cae06b14c0
rip=0000000000000000 rsp=000000dc2ab06598 rbp=000002cae06b14c0
 r8=0000000000000000  r9=0000000000000000 r10=000002cae06a9ea8
r11=000000dc2ab06590 r12=0000000000000000 r13=00000000000002d0
r14=000002cae06b16b0 r15=0000000000000001
iopl=0         nv up ei pl nz na pe nc
cs=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010202
00000000`00000000 ??              ???
0:000> k
  *** Stack trace for last set context - .thread/.cxr resets it
 # Child-SP          RetAddr           Call Site
00 000000dc`2ab06598 00007ffa`26d586d4 0x0
01 000000dc`2ab065a0 00007ffa`26d54019 SDL2!GL_UpdateViewport+0xa4 [c:\users\aicom\sdl\src\render\opengl\sdl_render_gl.c @ 1081] 
02 000000dc`2ab06620 00007ffa`26d55053 SDL2!GL_ActivateRenderer+0x69 [c:\users\aicom\sdl\src\render\opengl\sdl_render_gl.c @ 304] 
03 000000dc`2ab06650 00007ffa`26d53f52 SDL2!GL_DestroyRenderer+0x33 [c:\users\aicom\sdl\src\render\opengl\sdl_render_gl.c @ 1599] 
04 000000dc`2ab066c0 00007ffa`26d5ef68 SDL2!GL_CreateRenderer+0x572 [c:\users\aicom\sdl\src\render\opengl\sdl_render_gl.c @ 570] 
05 000000dc`2ab06720 00007ff7`1f086e51 SDL2!SDL_CreateRenderer_REAL+0x138 [c:\users\aicom\sdl\src\render\sdl_render.c @ 349] 
06 000000dc`2ab06790 00000000`00000000 Moonlight!SdlRenderer::initialize+0x51 [c:\moonlight-qt\app\streaming\video\ffmpeg-renderers\sdlvid.cpp @ 69] 

0:000> ?? data
struct GL_RenderData * 0x000002ca`e06b16b0
   +0x000 context          : 0x00000000`00040000 Void
   +0x008 debug_enabled    : 0 ( SDL_FALSE )
   +0x00c GL_ARB_debug_output_supported : 0 ( SDL_FALSE )
   +0x010 errors           : 0n0
   +0x018 error_messages   : (null) 
   +0x020 next_error_callback : (null) 
   +0x028 next_error_userparam : (null) 
   +0x030 GL_ARB_texture_non_power_of_two_supported : 0 ( SDL_FALSE )
   +0x034 GL_ARB_texture_rectangle_supported : 0 ( SDL_FALSE )
   +0x038 current          : <anonymous-tag>
   +0x044 GL_EXT_framebuffer_object_supported : 0 ( SDL_FALSE )
   +0x048 framebuffers     : (null) 
   +0x050 glBegin          : 0x00007ffa`37ef6470     void  opengl32!glBegin+0
   +0x058 glBindTexture    : 0x00007ffa`37ef6d60     void  opengl32!glBindTexture+0
   +0x060 glBlendEquation  : (null) 
   +0x068 glBlendFuncSeparate : (null) 
   +0x070 glClear          : (null) 
   +0x078 glClearColor     : (null) 
   +0x080 glColor3fv       : (null) 
   +0x088 glColor4f        : (null) 
   +0x090 glDeleteTextures : (null) 
   +0x098 glDepthFunc      : (null) 
   +0x0a0 glDisable        : (null) 
   +0x0a8 glDrawPixels     : (null) 
   +0x0b0 glEnable         : (null) 
   +0x0b8 glEnd            : (null) 
   +0x0c0 glGenTextures    : (null) 
   +0x0c8 glGetError       : (null) 
   +0x0d0 glGetIntegerv    : (null) 
   +0x0d8 glGetPointerv    : (null) 
   +0x0e0 glGetString      : (null) 
   +0x0e8 glLineWidth      : (null) 
   +0x0f0 glLoadIdentity   : (null) 
   +0x0f8 glMatrixMode     : (null) 
   +0x100 glOrtho          : (null) 
   +0x108 glPixelStorei    : (null) 
   +0x110 glPointSize      : (null) 
   +0x118 glPopMatrix      : (null) 
   +0x120 glPushMatrix     : (null) 
   +0x128 glRasterPos2i    : (null) 
   +0x130 glReadBuffer     : (null) 
   +0x138 glReadPixels     : (null) 
   +0x140 glRectf          : (null) 
   +0x148 glRotated        : (null) 
   +0x150 glRotatef        : (null) 
   +0x158 glScissor        : (null) 
   +0x160 glShadeModel     : (null) 
   +0x168 glTexCoord2f     : (null) 
   +0x170 glTexEnvf        : (null) 
   +0x178 glTexImage2D     : (null) 
   +0x180 glTexParameteri  : (null) 
   +0x188 glTexSubImage2D  : (null) 
   +0x190 glTranslatef     : (null) 
   +0x198 glVertex2f       : (null) 
   +0x1a0 glVertex3fv      : (null) 
   +0x1a8 glViewport       : (null) 
   +0x1b0 GL_ARB_multitexture_supported : 0 ( SDL_FALSE )
   +0x1b8 glActiveTextureARB : (null) 
   +0x1c0 num_texture_units : 0n0
   +0x1c8 glGenFramebuffersEXT : (null) 
   +0x1d0 glDeleteFramebuffersEXT : (null) 
   +0x1d8 glFramebufferTexture2DEXT : (null) 
   +0x1e0 glBindFramebufferEXT : (null) 
   +0x1e8 glCheckFramebufferStatusEXT : (null) 
   +0x1f0 shaders          : (null)