filter-branch: Export variable `workdir' for --commit-filter

According to `git help filter-branch':

       --commit-filter <command>
           ...
           You can use the _map_ convenience function in this filter,
           and other convenience functions, too...
           ...

However, it turns out that `map' hasn't been usable because it depends
on the variable `workdir', which is not propogated to the environment
of the shell that runs the commit-filter <command> because the
shell is created via a simple-command rather than a compound-command
subshell:

 @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
                 $(git write-tree) $parentstr < ../message > ../map/$commit ||
                         die "could not write rewritten commit"

One solution is simply to export `workdir'. However, it seems rather
heavy-handed to export `workdir' to the environments of all commands,
so instead this commit exports `workdir' for only the duration of the
shell command in question:

 workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
                 $(git write-tree) $parentstr < ../message > ../map/$commit ||
                         die "could not write rewritten commit"

Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 962a93b586571eb6fc60aae53c77f6e6b9fb281f..6b5f2251b6b5f0b9a43e16296c390e991c6fa13a 100755 (executable)
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -363,7 +363,7 @@ while read commit parents; do
        sed -e '1,/^$/d' <../commit | \
                eval "$filter_msg" > ../message ||
                        die "msg filter failed: $filter_msg"
-       @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
+       workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
                $(git write-tree) $parentstr < ../message > ../map/$commit ||
                        die "could not write rewritten commit"
 done <../revs