Re: cherry-pick / pre-commit hook?

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Dec 8, 2010, 22:05 UTC
Message-ID: <20101208220514.GA8865@burratino>
In-Reply-To: <m2oc8wt0xc.wl%dave@boostpro.com>

Dave Abrahams wrote:

Show 5 quoted lines

> You're going to love this: I had sent a pull request upstream and the
> maintainer of the project rejected my changes because I didn't follow
> some formatting convention he didn't tell me about ;-).  So I set up a
> commit hook that would prevent me from making the same mistake again,
> and cherry-picked the changes one-by-one.

Funny. Maybe "cherry-pick --no-commit" followed by ordinary commit would be appropriate? That way, when the checks fail, you are in a position to clean them up.

If the conventions were whitespace related, "git rebase --whitespace=fix" might be even more useful.

Just for kicks, here is the cherry-pick --verify for picky cherry-pickers.

-- 8< --
Subject: cherry-pick/revert: learn --verify to run pre-commit and commit-msg hooks

The main purpose of the pre-commit and commit-msg hooks is to avoid introducing regressions in whitespace style, encoding, and so forth; and it would make cherry-picking unnecessarily difficult, without preventing regressions, to unconditionally apply the same standards to existing code. For this reason, in v0.99.6~51 (2005-08-29), git learned to skip the usual hooks when cherry-picking or reverting an existing commit.

But sometimes the checks are wanted anyway. For example, with this patch applied, you can safely fetch some new contributor's code:

	$ git cherry-pick -s --verify HEAD..FETCH_HEAD

while allowing the pre-commit and commit-msg hooks to run their usual checks so the result can error out if the patches are not clean.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Untested.  Please feel free to add some documentation and tests and
submit it for real if this looks like a good idea. :)

 builtin/revert.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/builtin/revert.c b/builtin/revert.c
index bb6e9e8..511b2ea 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -36,7 +36,7 @@ static const char * const cherry_pick_usage[] = {
 	NULL
 };
 
-static int edit, no_replay, no_commit, mainline, signoff, allow_ff;
+static int edit, no_replay, no_commit, verify, mainline, signoff, allow_ff;
 static enum { REVERT, CHERRY_PICK } action;
 static struct commit *commit;
 static int commit_argc;
@@ -67,6 +67,7 @@ static void parse_args(int argc, const char **argv)
 		OPT_INTEGER('m', "mainline", &mainline, "parent number"),
 		OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
 		OPT_STRING(0, "strategy", &strategy, "strategy", "merge strategy"),
+		OPT_BOOLEAN(0, "verify", &verify, "let hooks intervene before commiting"),
 		OPT_END(),
 		OPT_END(),
 		OPT_END(),
@@ -375,7 +376,8 @@ static int run_git_commit(const char *defmsg)
 	int i = 0;
 
 	args[i++] = "commit";
-	args[i++] = "-n";
+	if (!verify)
+		args[i++] = "-n";
 	if (signoff)
 		args[i++] = "-s";
 	if (!edit) {

-- 
1.7.2.4