James McCoydf062010 (filter-branch: avoid passing commit message through sed) introduced a regression when filtering commits with multi-line headers, if the header contains a blank line. An example of this is a gpg-signed commit:
$ git cat-file commit signed-commit tree 3d4038e029712da9fc59a72afbfcc90418451630 parent 110eac945dc1713b27bdf49e74e5805db66971f0 author A U Thor <author@example.com> 1112912413 -0700 committer C O Mitter <committer@example.com> 1112912413 -0700 gpgsig -----BEGIN PGP SIGNATURE----- Version: GnuPG v1
iEYEABECAAYFAlYXADwACgkQE7b1Hs3eQw23CACgldB/InRyDgQwyiFyMMm3zFpj pUsAnA+f3aMUsd9mNroloSmlOgL6jIMO =0Hgm -----END PGP SIGNATURE-----
Adding gpg
As a consequence, "filter-branch --msg-filter cat" (which should leave the commit message unchanged) spills the signature (after the internal blank line) into the original commit message.
The reason is that although the signature is indented, making the line a whitespace only line, the “read” call is splitting the line based on the shell's IFS, which defaults to <space><tab><newline>. The leading space is consumed and $header_line is empty, causing the “skip header lines” loop to exit.
The rest of the commit object is then re-used as the rewritten commit message, causing the new message to include the signature of the original commit.
Set IFS to an empty string for the “read” call, thus disabling the word splitting, which causes $header_line to be set to the non-empty value ' '. This allows the loop to fully consume the header lines before emitting the original, intact commit message.
Signed-off-by: James McCoy <vega.james@gmail.com> --- git-filter-branch.sh | 2 +- t/t7003-filter-branch.sh | 14 ++++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-)
Show changes to 2 files +15 −1
git-filter-branch.sh, t/t7003-filter-branch.sh
diff --git a/git-filter-branch.sh b/git-filter-branch.sh index 5b3f63d..fff8093 100755 --- a/git-filter-branch.sh +++ b/git-filter-branch.sh @@ -347,7 +347,7 @@ while read commit parents; do fi { - while read -r header_line && test -n "$header_line" + while IFS='' read -r header_line && test -n "$header_line" do # skip header lines... :; diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh index 855afda..377c648 100755 --- a/t/t7003-filter-branch.sh +++ b/t/t7003-filter-branch.sh @@ -2,6 +2,7 @@ test_description='git filter-branch' . ./test-lib.sh +. "$TEST_DIRECTORY/lib-gpg.sh" test_expect_success 'setup' ' test_commit A && @@ -292,6 +293,19 @@ test_expect_success 'Tag name filtering strips gpg signature' ' test_cmp expect actual ' +test_expect_success GPG 'Filtering retains message of gpg signed commit' ' + mkdir gpg && + touch gpg/foo && + git add gpg && + test_tick && + git commit -S -m "Adding gpg" && + + git log -1 --format="%s" > expect && + git filter-branch -f --msg-filter "cat" && + git log -1 --format="%s" > actual && + test_cmp expect actual +' + test_expect_success 'Tag name filtering allows slashes in tag names' ' git tag -m tag-with-slash X/1 && git cat-file tag X/1 | sed -e s,X/1,X/2, > expect &&
-- 2.6.1 -- James GPG Key: 4096R/331BA3DB 2011-12-05 James McCoy <jamessan@debian.org>
