Fixed meaningless Win32 video mode restore.

src/win32_monitor.c

@@ -81,6 +81,7 @@ GLboolean _glfwSetVideoMode(_GLFWmonitor* monitor, const GLFWvidmode* desired)
         return GL_FALSE;
     }
 
+    monitor->win32.modeChanged = GL_TRUE;
     return GL_TRUE;
 }
 
@@ -88,8 +89,12 @@ GLboolean _glfwSetVideoMode(_GLFWmonitor* monitor, const GLFWvidmode* desired)
 //
 void _glfwRestoreVideoMode(_GLFWmonitor* monitor)
 {
-    ChangeDisplaySettingsEx(monitor->win32.name,
+    if (monitor->win32.modeChanged)
-                            NULL, NULL, CDS_FULLSCREEN, NULL);
+    {
+        ChangeDisplaySettingsEx(monitor->win32.name,
+                                NULL, NULL, CDS_FULLSCREEN, NULL);
+        monitor->win32.modeChanged = GL_FALSE;
+    }
 }
 
 

src/win32_platform.h

@@ -234,6 +234,7 @@ typedef struct _GLFWmonitorWin32
 {
     // This size matches the static size of DISPLAY_DEVICE.DeviceName
     WCHAR               name[32];
+    GLboolean           modeChanged;
 
 } _GLFWmonitorWin32;