[gtk+] Document GDK_NATIVE_WINDOWS

[Matthias Clasen <matthiasc src gnome org>]

commit 23b88f26b969769c7d8a2d1ea0d50039cd7b8aa4
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Aug 24 10:37:46 2009 -0400

    Document GDK_NATIVE_WINDOWS
    
    Add a section in the release notes about it and list it
    in the docs with all the other environment variables.

 README.in                       |    7 +++++++
 docs/reference/gtk/running.sgml |   10 ++++++++++
 2 files changed, 17 insertions(+), 0 deletions(-)
---
diff --git a/README.in b/README.in
index c92639b..bc2f857 100644
--- a/README.in
+++ b/README.in
@@ -37,6 +37,13 @@ Release notes for 2.18
 * JPEG2000 support is no longer enabled by default. It must be
   explicitly turned on, by passing --with-libjasper to configure.
 
+* GDK has been reworked to implement 'client-side windows'. This offers
+  exciting new possibilities, such as transformed, offscreen rendering,
+  but it breaks some long-standing assumptions that applications may
+  have about GDK windows. Setting the environment variable
+  GDK_NATIVE_WINDOWS makes GDK create a native X11 window for each
+  GDK window, which might make problematic applications work better.
+
 
 Release notes for 2.16
 ======================
diff --git a/docs/reference/gtk/running.sgml b/docs/reference/gtk/running.sgml
index 4e32c25..4c3c97f 100644
--- a/docs/reference/gtk/running.sgml
+++ b/docs/reference/gtk/running.sgml
@@ -342,6 +342,16 @@ nevertheless.
 </formalpara>
 
 <formalpara>
+  <title><envar>GDK_NATIVE_WINDOWS</envar></title>
+
+  <para>
+    If set, GDK creates all windows as native windows. This can help
+    applications that make assumptions about 1-1 correspondence between
+    GDK windows and X11 windows.
+  </para>
+</formalpara>
+
+<formalpara>
   <title><envar>XDG_DATA_HOME</envar>, <envar>XDG_DATA_DIRS</envar></title>
 
   <para>