EGL: Only use EGL_EXT_present_opaque on Wayland

The EGL_EXT_present_opaque extension is primarily a workaround meant for
Wayland, even if the language in it doesn't mention this.  GLFW
previously always enabled this extension where supported.  This caused
issues on X11 when running the Nvidia binary blob.

This commit ensures the extension is only enabled on Wayland.

Fixes #2365

This was adapted to 3.3-stable from
46cebb5081.

CONTRIBUTORS.md

@@ -239,6 +239,7 @@ video tutorials.
  - Jari Vetoniemi
  - Ricardo Vieira
  - Nicholas Vitovitch
+ - Vladimír Vondruš
  - Simon Voordouw
  - Corentin Wallez
  - Torsten Walluhn

README.md

@@ -140,6 +140,7 @@ information on what to include when reporting a bug.
  - [Linux] Bugfix: Joysticks without buttons were ignored (#2042,#2043)
  - [Linux] Bugfix: A small amount of memory could leak if initialization failed (#2229)
    [EGL] Added loading of glvnd `libOpenGL.so.0` where available for OpenGL
+ - [EGL] Bugfix: `EGL_EXT_present_opaque` caused issues on X11 with Nvidia blob (#2365)
  - [GLX] Added loading of glvnd `libGLX.so.0` where available
 
 

src/egl_context.c

@@ -651,8 +651,10 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
     if (!fbconfig->doublebuffer)
         setAttrib(EGL_RENDER_BUFFER, EGL_SINGLE_BUFFER);
 
+#if defined(_GLFW_WAYLAND)
     if (_glfw.egl.EXT_present_opaque)
         setAttrib(EGL_PRESENT_OPAQUE_EXT, !fbconfig->transparent);
+#endif // _GLFW_WAYLAND
 
     setAttrib(EGL_NONE, EGL_NONE);