WGL: Fix pixel format count in a Parallels VM

In a Parallels VM wglGetPixelFormatAttribivARB returns fewer pixel
formats than DescribePixelFormat.  This broke context creation on
Windows in Parallels since the changes in
2c0f34b60f.  The previous version of the
code worked accidentally.

This adds a workaround by iterating through the minimum of both counts.
It should have no effect when running on conforming implementations.

Tested on Parallels by @ dougbinks.

Closes #2191
Fixes #2406
Fixes #2467

This was adapted to 3.3-stable from
00e86d4b73.

CONTRIBUTORS.md

@@ -45,6 +45,7 @@ video tutorials.
  - Bailey Cosier
  - Noel Cower
  - CuriouserThing
+ - Bill Currie
  - Jason Daly
  - danhambleton
  - Jarrod Davis
@@ -162,6 +163,7 @@ video tutorials.
  - Martins Mozeiko
  - James Murphy
  - Julian Møller
+ - NateIsStalling
  - ndogxj
  - F. Nedelec
  - Kristian Nielsen

README.md

@@ -128,6 +128,7 @@ information on what to include when reporting a bug.
  - [Wayland] Bugfix: Terminating the library before showing a window could segfault
  - [Wayland] Bugfix: Compilation failed on FreeBSD (#2445)
  - [Linux] Bugfix: `regfree´ was called on invalid data (#2464)
+ - [WGL] Bugfix: Context creation failed in Parallels VM (#2191,#2406,#2467)
 
 
 ## Contact

src/wgl_context.c

@@ -80,6 +80,23 @@ static int choosePixelFormat(_GLFWwindow* window,
 
     if (_glfw.wgl.ARB_pixel_format)
     {
+        // NOTE: In a Parallels VM WGL_ARB_pixel_format returns fewer pixel formats than
+        //       DescribePixelFormat, violating the guarantees of the extension spec
+        // HACK: Iterate through the minimum of both counts
+
+        const int attrib = WGL_NUMBER_PIXEL_FORMATS_ARB;
+        int extensionCount;
+
+        if (!wglGetPixelFormatAttribivARB(window->context.wgl.dc,
+                                          1, 0, 1, &attrib, &extensionCount))
+        {
+            _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                                 "WGL: Failed to retrieve pixel format attribute");
+            return 0;
+        }
+
+        nativeCount = _glfw_min(nativeCount, extensionCount);
+
         addAttrib(WGL_SUPPORT_OPENGL_ARB);
         addAttrib(WGL_DRAW_TO_WINDOW_ARB);
         addAttrib(WGL_PIXEL_TYPE_ARB);