1 files changed, 49 insertions, 0 deletions
diff --git a/gfx/src/X11UndefineNone.h b/gfx/src/X11UndefineNone.h
new file mode 100644
index 0000000000..3f0c4aef31
--- /dev/null
+++ b/gfx/src/X11UndefineNone.h
@@ -0,0 +1,49 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// The header <X11/X.h> defines "None" as a macro that expands to "0L".
+// This is terrible because many enumerations have an enumerator named "None".
+// To work around this, we undefine the macro "None", and define a replacement
+// macro named "X11None".
+// Include this header after including X11 headers, where necessary.
+#ifdef None
+#  undef None
+#  define X11None 0L
+// <X11/X.h> also defines "RevertToNone" as a macro that expands to "(int)None".
+// Since we are undefining "None", that stops working. To keep it working,
+// we undefine "RevertToNone" and redefine it in terms of "X11None".
+#  ifdef RevertToNone
+#    undef RevertToNone
+#    define RevertToNone (int)X11None
+#  endif
+#endif
+
+// X11 also defines Always, which conflicts with some style system enum variant
+// names, so get rid of that too, given we don't use it anywhere else.
+#ifdef Always
+#  undef Always
+#endif
+
+// And Complex...
+#ifdef Complex
+#  undef Complex
+#endif
+
+#ifdef CurrentTime
+#  undef CurrentTime
+#  define X11CurrentTime 0L
+#endif
+
+// X11/Xlib.h also defines True and False, get rid of those too for
+// the same reasons as above...
+#ifdef True
+#  undef True
+#  define X11True 1
+#endif
+#ifdef False
+#  undef False
+#  define X11False 0
+#endif