Fixed window position being incorrect on some WMs.

README.md

@@ -122,6 +122,8 @@ See the [GLFW documentation](http://www.glfw.org/docs/latest/).
                  of the actual resolution of the selected video mode
  - [X11] Bugfix: Screensaver override for full screen windows had a possible
                  race condition
+ - [X11] Bugfix: The reported window position did not account for the size of
+                 the window frame on some WMs
 
 
 ## Contact
@@ -151,6 +153,7 @@ skills.
 
  - Bobyshev Alexander
  - artblanc
+ - arturo
  - Matt Arsenault
  - Keith Bauer
  - John Bartholomew

src/x11_window.c

@@ -985,6 +985,17 @@ void _glfwPlatformGetWindowPos(_GLFWwindow* window, int* xpos, int* ypos)
     XTranslateCoordinates(_glfw.x11.display, window->x11.handle, _glfw.x11.root,
                           0, 0, &x, &y, &child);
 
+    if (child != None)
+    {
+        int left, top;
+
+        XTranslateCoordinates(_glfw.x11.display, window->x11.handle, child,
+                              0, 0, &left, &top, &child);
+
+        x -= left;
+        y -= top;
+    }
+
     if (xpos)
         *xpos = x;
     if (ypos)