filter-branch: stop depending on Perl

While git-filter-branch(1) is written as a shell script, the
`--state-branch` feature depends on Perl to save and extract the object
ID mappings. This can lead to subtle breakage though:

  - We execute `perl` directly without respecting the `PERL_PATH`
    configured by the distribution. As such, it may happen that we use
    the wrong version of Perl.

  - We install the script unchanged even if Perl isn't available at all
    on the system, so using `--state-branch` would lead to failure
    altogether in that case.

Fix this by dropping Perl and instead implementing the feature with
shell scripting exclusively.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
main
Patrick Steinhardt 2025-04-16 14:16:07 +02:00 committed by Junio C Hamano
parent 55f7879f57
commit f6d855091e
1 changed files with 19 additions and 18 deletions

View File

@ -295,15 +295,18 @@ then
if test -n "$state_commit"
then
echo "Populating map from $state_branch ($state_commit)" 1>&2
perl -e'open(MAP, "-|", "git show $ARGV[0]:filter.map") or die;
while (<MAP>) {
m/(.*):(.*)/ or die;
open F, ">../map/$1" or die;
print F "$2" or die;
close(F) or die;
}
close(MAP) or die;' "$state_commit" \
|| die "Unable to load state from $state_branch:filter.map"

git show "$state_commit:filter.map" >"$tempdir"/filter-map ||
die "Unable to load state from $state_branch:filter.map"
while read line
do
case "$line" in
*:*)
echo "${line%:*}" >../map/"${line#*:}";;
*)
die "Unable to load state from $state_branch:filter.map";;
esac
done <"$tempdir"/filter-map
else
echo "Branch $state_branch does not exist. Will create" 1>&2
fi
@ -633,15 +636,13 @@ if test -n "$state_branch"
then
echo "Saving rewrite state to $state_branch" 1>&2
state_blob=$(
perl -e'opendir D, "../map" or die;
open H, "|-", "git hash-object -w --stdin" or die;
foreach (sort readdir(D)) {
next if m/^\.\.?$/;
open F, "<../map/$_" or die;
chomp($f = <F>);
print H "$_:$f\n" or die;
}
close(H) or die;' || die "Unable to save state")
for file in ../map/*
do
from_commit=$(basename "$file")
to_commit=$(cat "$file")
echo "$from_commit:$to_commit"
done | git hash-object -w --stdin || die "Unable to save state"
)
state_tree=$(printf '100644 blob %s\tfilter.map\n' "$state_blob" | git mktree)
if test -n "$state_commit"
then