filter-branch: add `--setup` step
A `--setup` step in `git filter-branch` makes it much easier to
define the initial values of variables used in the real filters.
Also sourcing/defining utility functions here instead of
`--env-filter` improves performance and minimizes clogging the
output in case of errors.
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git-filter-branch.txt b/Documentation/git-filter-branch.txt
index 7b695db..9e5169a 100644
--- a/Documentation/git-filter-branch.txt
+++ b/Documentation/git-filter-branch.txt
@@ -8,11 +8,11 @@
SYNOPSIS
--------
[verse]
-'git filter-branch' [--env-filter <command>] [--tree-filter <command>]
- [--index-filter <command>] [--parent-filter <command>]
- [--msg-filter <command>] [--commit-filter <command>]
- [--tag-name-filter <command>] [--subdirectory-filter <directory>]
- [--prune-empty]
+'git filter-branch' [--setup <command>] [--env-filter <command>]
+ [--tree-filter <command>] [--index-filter <command>]
+ [--parent-filter <command>] [--msg-filter <command>]
+ [--commit-filter <command>] [--tag-name-filter <command>]
+ [--subdirectory-filter <directory>] [--prune-empty]
[--original <namespace>] [-d <directory>] [-f | --force]
[--] [<rev-list options>...]
@@ -82,6 +82,13 @@
OPTIONS
-------
+--setup <command>::
+ This is not a real filter executed for each commit but a one
+ time setup just before the loop. Therefore no commit-specific
+ variables are defined yet. Functions or variables defined here
+ can be used or modified in the following filter steps except
+ the commit filter, for technical reasons.
+
--env-filter <command>::
This filter may be used if you only need to modify the environment
in which the commit will be performed. Specifically, you might
diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index aafaf70..2758ae5 100755
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -81,11 +81,12 @@
finish_ident COMMITTER
}
-USAGE="[--env-filter <command>] [--tree-filter <command>]
- [--index-filter <command>] [--parent-filter <command>]
- [--msg-filter <command>] [--commit-filter <command>]
- [--tag-name-filter <command>] [--subdirectory-filter <directory>]
- [--original <namespace>] [-d <directory>] [-f | --force]
+USAGE="[--setup <command>] [--env-filter <command>]
+ [--tree-filter <command>] [--index-filter <command>]
+ [--parent-filter <command>] [--msg-filter <command>]
+ [--commit-filter <command>] [--tag-name-filter <command>]
+ [--subdirectory-filter <directory>] [--original <namespace>]
+ [-d <directory>] [-f | --force]
[<rev-list options>...]"
OPTIONS_SPEC=
@@ -96,6 +97,7 @@
fi
tempdir=.git-rewrite
+filter_setup=
filter_env=
filter_tree=
filter_index=
@@ -148,6 +150,9 @@
-d)
tempdir="$OPTARG"
;;
+ --setup)
+ filter_setup="$OPTARG"
+ ;;
--env-filter)
filter_env="$OPTARG"
;;
@@ -317,6 +322,9 @@
need_index=
fi
+eval "$filter_setup" < /dev/null ||
+ die "filter setup failed: $filter_setup"
+
while read commit parents; do
git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
