Re: [RFH] filter-branch: ancestor detection weirdness

From: Thomas Rast <trast@student.ethz.ch>
Date: Aug 9, 2008, 10:00 UTC
Message-ID: <200808091200.21634.trast@student.ethz.ch>
In-Reply-To: <alpine.DEB.1.00.0808090212060.24820@pacific.mpi-cbg.de.mpi-cbg.de>

Johannes Schindelin wrote:

> But hey, if other people agree with you, and this kind of thinking ends 
> up in Git proper, I can still resort to other DVCSes.

BTW, the following is fairly ironic. (It was later rewritten in 813b473 to the current one-shot 'rev-list --parents' form.)

commit 685ef546b62d063c72b401cd38b83a879301aac4
Author: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Date:   Fri Jun 8 01:30:35 2007 +0100

    Teach filter-branch about subdirectory filtering
    
    With git-filter-branch --subdirectory-filter <subdirectory> you can
    get at the history, as seen by a certain subdirectory. The history
    of the rewritten branch will only contain commits that touched that
    subdirectory, and the subdirectory will be rewritten to be the new
    project root.
    
    Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
[...snip...]
@@ -224,7 +228,13 @@ set_ident () {
 
 # list all parent's object names for a given commit
 get_parents () {
-	git-rev-list -1 --parents "$1" | sed "s/^[0-9a-f]*//"
+	case "$filter_subdir" in
+	"")
+		git-rev-list -1 --parents "$1"
+		;;
+	*)
+		git-rev-list -1 --parents "$1" -- "$filter_subdir"
+	esac | sed "s/^[0-9a-f]*//"
 }
 
 tempdir=.git-rewrite
[...snip...]

-- 
Thomas Rast
trast@student.ethz.ch