[jhbuild] Document git branch attributes (GNOME bug 620974)

[Frederic Peters <fpeters src gnome org>]

commit b4ec0b83700877e1d7bc5da3ff74c9f550bca9a5
Author: Dirk Wallenstein <halsmit t-online de>
Date:   Tue Jun 8 13:07:36 2010 +0200

    Document git branch attributes (GNOME bug 620974)
    
    Add documentation for the git branch attributes 'revision' and 'tag',
    which allow to switch to a different state during the update phase.

 doc/C/jhbuild.xml |   30 +++++++++++++++++++++++-------
 1 files changed, 23 insertions(+), 7 deletions(-)
---
diff --git a/doc/C/jhbuild.xml b/doc/C/jhbuild.xml
index e1b3fe1..0f22cb2 100644
--- a/doc/C/jhbuild.xml
+++ b/doc/C/jhbuild.xml
@@ -2281,16 +2281,32 @@ libgnomecanvas is missing branch definition for gnome-2-20
     href="git://anongit.freedesktop.org/git/"/&gt;
         </programlisting>
 
+        <para>It allows the following attributes on the <sgmltag
+        class="element">branch</sgmltag> element:</para>
+
+        <para>The <sgmltag class="attribute">revision</sgmltag>
+        attribute is used to specify a local or remote-tracking branch
+        to switch to in the update phase. It defaults to 'master'. It is
+        possible to override this attribute with the
+        <varname>branches</varname> configuration variable. The switch
+        will only be performed, if the current branch is tracking a
+        remote branch, to not disturb your own work.</para>
+
+        <para>The <sgmltag class="attribute">tag</sgmltag>
+        attribute is used to specify a revision to unconditionally check
+        out in the update phase. It overrides the <sgmltag
+        class="attribute">revision</sgmltag> attribute.</para>
+
+        <!-- TODO I can't say much about the subdir attribute. In the
+        end it will just be appended to checkoutdir.
+        https://bugzilla.gnome.org/show_bug.cgi?id=342846
+        -->
+
         <programlisting>
 &lt;branch repo="git.freedesktop.org" module="swfdec/swfdec"
         checkoutdir="swfdec"
-        tag="tree-ish"/&gt;
-        </programlisting>
-
-        <!-- FIXME revision attribute, verity I don't use it -->
-        <programlisting>
-&lt;branch repo="git.gcc.gnu.org" module="gcc.git"
-        revision="git-svn revision"/&gt;
+        revision="<replaceable>local-or-remote-branch</replaceable>"
+        tag="<replaceable>tree-ish</replaceable>"/&gt;
         </programlisting>
       </section>