[PATCH/RFC] git-post: the opposite of git-cherry-pick
- From
Johannes Sixt <j6t@kdbg.org>
- Date
- Oct 5, 2017, 19:13 UTC
- Message-ID
- <c6b52120-98bf-d685-6dc0-3c83e9e80d30@kdbg.org>
Add a new command that can be used to copy an arbitrary commit to a branch that is not checked out.
Signed-off-by: Johannes Sixt <j6t@kdbg.org> --- I have been using this command since years, but got around to write a man page and tests only now. I hope the man page makes sense. I don't have the tool chain to build it, though, so any hints for improvement are welcome.
.gitignore | 1 + Documentation/git-cherry-pick.txt | 3 +- Documentation/git-post.txt | 57 +++++++++++++++++++++++++++++ Makefile | 1 + command-list.txt | 1 + git-post.sh | 60 ++++++++++++++++++++++++++++++ t/t3514-post.sh | 77 +++++++++++++++++++++++++++++++++++++++ 7 files changed, 199 insertions(+), 1 deletion(-) create mode 100644 Documentation/git-post.txt create mode 100755 git-post.sh create mode 100755 t/t3514-post.sh
diff --git a/.gitignore b/.gitignore index 833ef3b0b7..a16263249a 100644 --- a/.gitignore +++ b/.gitignore @@ -106,6 +106,7 @@ /git-pack-refs /git-parse-remote /git-patch-id +/git-post /git-prune /git-prune-packed /git-pull diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt index d35d771fc8..6b34f4d994 100644 --- a/Documentation/git-cherry-pick.txt +++ b/Documentation/git-cherry-pick.txt @@ -226,7 +226,8 @@ context lines. SEE ALSO -------- -linkgit:git-revert[1] +linkgit:git-revert[1], +linkgit:git-post[1] GIT --- diff --git a/Documentation/git-post.txt b/Documentation/git-post.txt new file mode 100644 index 0000000000..e835e62be3 --- /dev/null +++ b/Documentation/git-post.txt @@ -0,0 +1,57 @@ +git-post(1) +=========== + +NAME +---- +git-post - Apply a commit on top of a branch that is not checked out + +SYNOPSIS +-------- +[verse] +'git post' dest-branch [source-rev] + +DESCRIPTION +----------- + +Applies the changes made by 'source-rev' (or, if not given, `HEAD`) +on top of the branch 'dest-branch' and records a new commit. +'dest-branch' is advanced to point to the new commit. +The operation that this command performs can be regarded as +the opposite of cherry-picking. + +EXAMPLES +-------- + +Assume, while working on a topic, you find and fix an unrelated bug. +Now: + +------------ +$ git commit <1> +$ git post master <2> +$ git show | git apply -R && git reset HEAD^ <3> +------------ + +<1> create a commit with the fix on the current branch +<2> copy the fix onto the branch where it ought to be +<3> revert current topic branch to the unfixed state; +can also be done with `git reset --keep HEAD^` if there are no +unstaged changes in files that are modified by the fix + +Oftentimes, switching branches triggers a rebuild of a code base. +With the sequence above the branch switch can be avoided. +That said, it is good practice to test the bug fix on the +destination branch eventually. + +BUGS +---- + +The change can be applied on `dest-branch` only if there is +no textual conflict. + +SEE ALSO +-------- +linkgit:git-cherry-pick[1]. + +GIT +--- +Part of the linkgit:git[1] suite diff --git a/Makefile b/Makefile index b143e4eea3..1753bf176f 100644 --- a/Makefile +++ b/Makefile @@ -551,6 +551,7 @@ SCRIPT_SH += git-merge-octopus.sh SCRIPT_SH += git-merge-one-file.sh SCRIPT_SH += git-merge-resolve.sh SCRIPT_SH += git-mergetool.sh +SCRIPT_SH += git-post.sh SCRIPT_SH += git-quiltimport.sh SCRIPT_SH += git-rebase.sh SCRIPT_SH += git-remote-testgit.sh diff --git a/command-list.txt b/command-list.txt index a1fad28fd8..bc95b424d0 100644 --- a/command-list.txt +++ b/command-list.txt @@ -98,6 +98,7 @@ git-pack-redundant plumbinginterrogators git-pack-refs ancillarymanipulators git-parse-remote synchelpers git-patch-id purehelpers +git-post mainporcelain git-prune ancillarymanipulators git-prune-packed plumbingmanipulators git-pull mainporcelain remote diff --git a/git-post.sh b/git-post.sh new file mode 100755 index 0000000000..6627d69f73 --- /dev/null +++ b/git-post.sh @@ -0,0 +1,60 @@ +#!/bin/sh +# Copyright (c) 2017 Johannes Sixt + +SUBDIRECTORY_OK=Yes +OPTIONS_SPEC="\ +git post dest-branch [source-rev] +-- +" +. git-sh-setup + +while test $# != 0 +do + case "$1" in + --) shift; break;; + -*) usage;; + *) break;; + esac + shift +done + +dest=$(git rev-parse --verify --symbolic-full-name "$1") || exit +if test -z "$dest" +then + die "$(gettext "Destination must be a branch tip")" +fi + +shift +case $# in +0) set -- HEAD;; +1) : good;; +*) usage;; +esac + +# apply change to a temporary index +tmpidx=$GIT_DIR/index-post-$$ +git read-tree --index-output="$tmpidx" "$dest" || exit +GIT_INDEX_FILE=$tmpidx +export GIT_INDEX_FILE +trap 'rm -f "$tmpidx"' 0 1 2 15 + +git diff-tree -p --binary -M -C "$1" | git apply --cached || exit + +newtree=$(git write-tree) && +newrev=$( + eval "$(get_author_ident_from_commit "$1")" && + export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE + git-cat-file commit "$1" | sed -e '1,/^$/d' | + git commit-tree $newtree -p "$dest" +) || exit + +if git check-ref-format "$dest" +then + set_reflog_action post + subject=$(git log --no-walk --pretty=%s "$newrev") && + git update-ref -m "$GIT_REFLOG_ACTION: $subject" "$dest" "$newrev" || exit +fi +if test -z "$GIT_QUIET" +then + git rev-list -1 --oneline "$newrev" +fi diff --git a/t/t3514-post.sh b/t/t3514-post.sh new file mode 100755 index 0000000000..4d31515c52 --- /dev/null +++ b/t/t3514-post.sh @@ -0,0 +1,77 @@ +#!/bin/sh + +test_description='test git post + +We build this history: + + A--B--C <-- master, HEAD + / + O <-- side-base, side + +Then we post B and C on top of branch "side": + + A--B--C <-- master, HEAD + / + O <-- side-base + \ + B*--C* <-- side + +B has a different author, which must be copied to B*. +' + +. ./test-lib.sh + +test_expect_success setup ' + + printf "a%s\n" 1 2 3 4 >file-a && + printf "b%s\n" 5 6 7 8 >file-b && + + test_tick && + git add file-a file-b && + git commit -m initial && + git tag side-base && + + test_tick && + echo "Advance master" >>file-a && + git commit -a -m advance-master && + + test_tick && + echo "Unrelated fix" >>file-b && + GIT_AUTHOR_NAME="S O Else" git commit -a -m fix-for-b && + + test_tick && + echo "Another fix" >>file-b && + git commit -a -m another-fix-for-b +' + +test_expect_success 'post two commits on top of side' ' + + git branch -f side side-base && + test_tick && + git post side HEAD^ && + test_tick && + git post side && + + git log --pretty="%at %an %ae %s" HEAD~2.. >expect && + git log --pretty="%at %an %ae %s" side-base..side >actual && + + test_cmp expect actual && + git cat-file blob side:file-b >actual && + test_cmp file-b actual && + + git diff --exit-code side-base side -- file-a # no change +' + +test_expect_success 'post requiring merge resolution fails' ' + + git branch -f side side-base && + test_must_fail git post side HEAD +' + +test_expect_success 'cannot post onto arbitrary commit name' ' + + git branch -f side side-base && + test_must_fail git post side^0 HEAD^ +' + +test_done
-- 2.14.2.808.g3bc32f2729