Fix error type for unavailable pixel format error

All backends reported this as GLFW_PLATFORM_ERROR, while the
documentation mandates GLFW_FORMAT_UNAVAILABLE.

README.md

@@ -102,13 +102,17 @@ GLFW bundles a number of dependencies in the `deps/` directory.
  - [WGL] Made all WGL functions dynamically loaded
  - [WGL] Removed `GLFW_USE_DWM_SWAP_INTERVAL` compile-time option
  - [WGL] Bugfix: Swap interval was ignored when DWM was enabled
+ - [WGL] Bugfix: Failure to find a pixel format was reported incorrectly
  - [GLX] Added dependency on `libdl` on systems where it provides `dlopen`
  - [GLX] Made all GLX functions dynamically loaded
  - [GLX] Removed `_GLFW_HAS_GLXGETPROCADDRESS*` and `_GLFW_HAS_DLOPEN`
          compile-time options
+ - [GLX] Bugfix: Failure to find a `GLXFBConfig` was reported incorrectly
  - [EGL] Made all EGL functions dynamically loaded
  - [EGL] Bugfix: `glfwGetProcAddress` did not return the addresses of core
                  functions
+ - [EGL] Bugfix: Failure to find an `EGLConfig` was reported incorrectly
+ - [NSGL] Bugfix: Failure to find a pixel format was reported incorrectly
 
 
 ## Contact

src/egl_context.c

@@ -306,7 +306,7 @@ int _glfwCreateContext(_GLFWwindow* window,
 
     if (!chooseFBConfigs(ctxconfig, fbconfig, &config))
     {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
+        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
                         "EGL: Failed to find a suitable EGLConfig");
         return GL_FALSE;
     }

src/glx_context.c

@@ -321,7 +321,7 @@ int _glfwCreateContext(_GLFWwindow* window,
 
     if (!chooseFBConfig(fbconfig, &native))
     {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
+        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
                         "GLX: Failed to find a suitable GLXFBConfig");
         return GL_FALSE;
     }

src/nsgl_context.m

@@ -211,8 +211,8 @@ int _glfwCreateContext(_GLFWwindow* window,
         [[NSOpenGLPixelFormat alloc] initWithAttributes:attributes];
     if (window->nsgl.pixelFormat == nil)
     {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "NSGL: Failed to create OpenGL pixel format");
+        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
+                        "NSGL: Failed to find a suitable pixel format");
         return GL_FALSE;
     }
 

src/wgl_context.c

@@ -250,7 +250,7 @@ static GLboolean choosePixelFormat(_GLFWwindow* window,
     closest = _glfwChooseFBConfig(desired, usableConfigs, usableCount);
     if (!closest)
     {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
+        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
                         "WGL: Failed to find a suitable pixel format");
 
         free(usableConfigs);