post-checkout hook not run on clone

I realize this might be a feature, but when I switch to the master
branch with "git checkout master" it is, and I would think that a
clone that gets the master branch would also does a sort of "checkout
master" and would run the hook.

In any case, I'd be happy of there was a post-clone hook, instead, but
there isn't.

Any suggestions?

Thanks.

Kevin

On Mon, Mar 02, 2009 at 02:43:37PM -0800, layer wrote:

I realize this might be a feature, but when I switch to the master
branch with "git checkout master" it is, and I would think that a
clone that gets the master branch would also does a sort of "checkout
master" and would run the hook.

Right. Hooks are not cloned with the repo.

In any case, I'd be happy of there was a post-clone hook, instead, but
there isn't.

The general wisdom on the list is that it's a bad idea to run remote
code arbitrarily for security reasons (i.e., "git clone
git://host/foo.git" should not automatically run code from "host"). Even
if you are going to build and run the contents of "foo.git", you at
least have a chance to inspect the changes via git.

However, for situations where you are OK implicitly trusting the remote,
it is obviously less convenient.

Any suggestions?

Most suggestions I have seen involve shipping the hooks in your repo,
and then having users copy them to their .git/hooks directory (and you
can even provide a script for that).

Unfortunately, there is a chicken-and-egg problem there with the initial
checkout. You could do something like (assuming the hooks are in "hooks"
in the repo) to bootstrap:

  git clone -n <repo.git>
  cd repo
  git archive --format tar HEAD hooks | tar -C .git/hooks -xf -
  git checkout master

-Peff

Jeff King [off-list ref] wrote:

quoted

On Mon, Mar 02, 2009 at 02:43:37PM -0800, layer wrote:

quoted

I realize this might be a feature, but when I switch to the master
branch with "git checkout master" it is, and I would think that a
clone that gets the master branch would also does a sort of "checkout
master" and would run the hook.

Right. Hooks are not cloned with the repo.

The hook in question was in /usr/share/git-core/templates/hooks/, so
it would get setup on clone.  That works fine.  If I immediately
switch branches, the hook gets called.  It's just the `post-clone'
(when I assume something like `checkout' is done), the hook doesn't
get called.

quoted

The general wisdom on the list is that it's a bad idea to run remote
code arbitrarily for security reasons...

I agree, but not in this specific situation.  All the users of the
code are trusted, as is the author of the hooks.

Jeff King [off-list ref] wrote:

On Mon, Mar 02, 2009 at 02:43:37PM -0800, layer wrote:

quoted

I realize this might be a feature, but when I switch to the master
branch with "git checkout master" it is, and I would think that a
clone that gets the master branch would also does a sort of "checkout
master" and would run the hook.

Right. Hooks are not cloned with the repo.

I think the original poster was talking about a hook installed via
their template directory.  In which case the hook is trusted, and is
coming from a known source, its just not being called during clone.
 
-- 
Shawn.

On Mon, Mar 02, 2009 at 09:02:29PM -0800, layer wrote:

The hook in question was in /usr/share/git-core/templates/hooks/, so
it would get setup on clone.  That works fine.  If I immediately
switch branches, the hook gets called.  It's just the `post-clone'
(when I assume something like `checkout' is done), the hook doesn't
get called.

Ah, OK. I misunderstood. Then that is a bug, IMHO. Patch in a minute.

-Peff

The mental model for clone is that the branch is "checked
out" (and it even says this in Documentation/git-clone.txt:
"...creates and checks out an initial branch"). Therefore it
is reasonable for users to expect that any post-checkout
hook would be run.

Signed-off-by: Jeff King <redacted>
---
On Mon, Mar 02, 2009 at 09:02:29PM -0800, layer wrote:

The hook in question was in /usr/share/git-core/templates/hooks/, so
it would get setup on clone.  That works fine.  If I immediately
switch branches, the hook gets called.  It's just the `post-clone'
(when I assume something like `checkout' is done), the hook doesn't
get called.

This should fix it.

Junio, I'm not sure what you want to do with this. It is definitely a
behavior change; we have never respected post-checkout hooks in shell
git-clone.sh or in the builtin version. However, it seems like an
omission rather than an intentional behavior, so I consider this a
bugfix.

 builtin-clone.c               |    7 ++++++-
 t/t5403-post-checkout-hook.sh |   12 ++++++++++++
 2 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/builtin-clone.c b/builtin-clone.c
index 3146ca8..ceffecb 100644
--- a/builtin-clone.c
+++ b/builtin-clone.c

@@ -21,6 +21,7 @@
 #include "pack-refs.h"
 #include "sigchain.h"
 #include "remote.h"
+#include "run-command.h"
 
 /*
  * Overall FIXMEs:

@@ -341,6 +342,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 	struct transport *transport = NULL;
 	char *src_ref_prefix = "refs/heads/";
+	int err = 0;
 
 	struct refspec refspec;
 

@@ -596,6 +598,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		if (write_cache(fd, active_cache, active_nr) ||
 		    commit_locked_index(lock_file))
 			die("unable to write new index file");
+
+		err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
+				sha1_to_hex(remote_head->old_sha1), "1", NULL);
 	}
 
 	strbuf_release(&reflog_msg);

@@ -603,5 +608,5 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	strbuf_release(&key);
 	strbuf_release(&value);
 	junk_pid = 0;
-	return 0;
+	return err;
 }

diff --git a/t/t5403-post-checkout-hook.sh b/t/t5403-post-checkout-hook.sh
index 9b2e1a9..4fdb418 100755
--- a/t/t5403-post-checkout-hook.sh
+++ b/t/t5403-post-checkout-hook.sh

@@ -71,4 +71,16 @@ test_expect_success 'post-checkout receives the right args when not switching br
         test $old = $new -a $flag = 0
 '
 
+mkdir -p templates/hooks
+cat >templates/hooks/post-checkout <<'EOF'
+#!/bin/sh
+echo $@ > $GIT_DIR/post-checkout.args
+EOF
+chmod +x templates/hooks/post-checkout
+
+test_expect_success 'post-checkout hook is triggered by clone' '
+	git clone --template=templates . clone3 &&
+	test -f clone3/.git/post-checkout.args
+'
+
 test_done

-- 
1.6.2.rc2.313.gce9b3.dirty

Jeff,

Thanks very much for doing this.

Kevin