relinquish the mouse capture when a dialog is about to be made modal to ensure that the mouse can be used in it (patch 1754648)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@48121 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/dialog.cpp

@@ -112,6 +112,13 @@ int wxDialog::ShowModal()
        return GetReturnCode();
     }
 
+    // release the mouse if it's currently captured as the window having it
+    // will be disabled when this dialog is shown -- but will still keep the
+    // capture making it impossible to do anything in the modal dialog itself
+    wxWindow * const win = wxWindow::GetCapture();
+    if ( win )
+        win->GTKReleaseMouseAndNotify();
+
     // use the apps top level window as parent if none given unless explicitly
     // forbidden
     if ( !GetParent() && !(GetWindowStyleFlag() & wxDIALOG_NO_PARENT) )