Merge branch 'master' into jgrpp

# Conflicts:
#	src/debug.cpp
#	src/lang/russian.txt
#	src/misc_gui.cpp
#	src/os/windows/crashlog_win.cpp
#	src/os/windows/font_win32.cpp
#	src/os/windows/win32.cpp
#	src/rail_cmd.cpp
#	src/window_gui.h

src/window.cpp

@@ -1185,8 +1185,7 @@ Window *FindWindowByClass(WindowClass cls)
 void DeleteWindowById(WindowClass cls, WindowNumber number, bool force)
 {
 	Window *w = FindWindowById(cls, number);
-	if (force || w == nullptr ||
-			(w->flags & WF_STICKY) == 0) {
+	if (w != nullptr && (force || (w->flags & WF_STICKY) == 0)) {
 		delete w;
 	}
 }