repack.usedeltabaseoffset config option now defaults to "true"

As announced for 1.6.0.

Access over the native protocol by old git versions is unaffected as
this capability is negociated by the protocol.  Otherwise setting this
config option to "false" and doing a 'git repack -a -d' is enough to
remain compatible with ancient git versions (older than 1.4.4).

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -996,8 +996,12 @@ remotes.<group>::
 	<group>".  See linkgit:git-remote[1].
 
 repack.usedeltabaseoffset::
-	Allow linkgit:git-repack[1] to create packs that uses
-	delta-base offset.  Defaults to false.
+	By default, linkgit:git-repack[1] creates packs that use
+	delta-base offset. If you need to share your repository with
+	git older than version 1.4.4, either directly or via a dumb
+	protocol such as http, then you need to set this option to
+	"false" and repack. Access from old git versions over the
+	native protocol are unaffected by this option.
 
 show.difftree::
 	The default linkgit:git-diff-tree[1] arguments to be used

git-repack.sh

@@ -44,11 +44,7 @@ do
 	shift
 done
 
-# Later we will default repack.UseDeltaBaseOffset to true
-default_dbo=false
-
-case "`git config --bool repack.usedeltabaseoffset ||
-       echo $default_dbo`" in
+case "`git config --bool repack.usedeltabaseoffset || echo true`" in
 true)
 	extra="$extra --delta-base-offset" ;;
 esac