Re: [PATCH 05/11] reset_head(): factor out ref updates

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 1, 2021, 21:00 UTC
Message-ID: <xmqqlf3c5ul1.fsf@gitster.g>
In-Reply-To: <0744c3d143b5c2020267c5f9ad7da9303d7a7835.1633082702.git.gitgitgadget@gmail.com>

"Phillip Wood via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> In the next commit we will stop trying to update HEAD when we are just
> clearing changes from the working tree. Move the code that updates the

"clearing changes" meaning...?  Like "rebase --abort"?

Show 158 quoted lines

> refs to its own function in preparation for that.
>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
>  reset.c | 112 +++++++++++++++++++++++++++++++-------------------------
>  1 file changed, 62 insertions(+), 50 deletions(-)
>
> diff --git a/reset.c b/reset.c
> index 9ab007c0c34..668c7639127 100644
> --- a/reset.c
> +++ b/reset.c
> @@ -8,26 +8,75 @@
>  #include "tree.h"
>  #include "unpack-trees.h"
>  
> +static int update_refs(const struct object_id *oid, const char *switch_to_branch,
> +		       const char *reflog_head, const char *reflog_orig_head,
> +		       const char *default_reflog_action, unsigned flags)
> +{
> +	unsigned detach_head = flags & RESET_HEAD_DETACH;
> +	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
> +	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
> +	struct object_id *orig = NULL, oid_orig, *old_orig = NULL, oid_old_orig;
> +	struct strbuf msg = STRBUF_INIT;
> +	const char *reflog_action;
> +	size_t prefix_len;
> +	int ret;
> +
> +	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
> +	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
> +	prefix_len = msg.len;
> +
> +	if (update_orig_head) {
> +		if (!get_oid("ORIG_HEAD", &oid_old_orig))
> +			old_orig = &oid_old_orig;
> +		if (!get_oid("HEAD", &oid_orig)) {
> +			orig = &oid_orig;
> +			if (!reflog_orig_head) {
> +				strbuf_addstr(&msg, "updating ORIG_HEAD");
> +				reflog_orig_head = msg.buf;
> +			}
> +			update_ref(reflog_orig_head, "ORIG_HEAD", orig,
> +				   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
> +		} else if (old_orig)
> +			delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
> +	}
> +
> +	if (!reflog_head) {
> +		strbuf_setlen(&msg, prefix_len);
> +		strbuf_addstr(&msg, "updating HEAD");
> +		reflog_head = msg.buf;
> +	}
> +	if (!switch_to_branch)
> +		ret = update_ref(reflog_head, "HEAD", oid, orig,
> +				 detach_head ? REF_NO_DEREF : 0,
> +				 UPDATE_REFS_MSG_ON_ERR);
> +	else {
> +		ret = update_ref(reflog_head, switch_to_branch, oid,
> +				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
> +		if (!ret)
> +			ret = create_symref("HEAD", switch_to_branch,
> +					    reflog_head);
> +	}
> +	if (!ret && run_hook)
> +		run_hook_le(NULL, "post-checkout",
> +			    oid_to_hex(orig ? orig : null_oid()),
> +			    oid_to_hex(oid), "1", NULL);
> +	strbuf_release(&msg);
> +	return ret;
> +}
> +
>  int reset_head(struct repository *r, struct object_id *oid,
>  	       const char *switch_to_branch, unsigned flags,
>  	       const char *reflog_orig_head, const char *reflog_head,
>  	       const char *default_reflog_action)
>  {
> -	unsigned detach_head = flags & RESET_HEAD_DETACH;
>  	unsigned reset_hard = flags & RESET_HEAD_HARD;
> -	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
>  	unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
> -	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
>  	struct object_id head_oid;
>  	struct tree_desc desc[2] = { { NULL }, { NULL } };
>  	struct lock_file lock = LOCK_INIT;
>  	struct unpack_trees_options unpack_tree_opts = { 0 };
>  	struct tree *tree;
> -	const char *action, *reflog_action;
> -	struct strbuf msg = STRBUF_INIT;
> -	size_t prefix_len;
> -	struct object_id *orig = NULL, oid_orig,
> -		*old_orig = NULL, oid_old_orig;
> +	const char *action;
>  	int ret = 0, nr = 0;
>  
>  	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
> @@ -47,7 +96,9 @@ int reset_head(struct repository *r, struct object_id *oid,
>  		oid = &head_oid;
>  
>  	if (refs_only)
> -		goto reset_head_refs;
> +		return update_refs(oid, switch_to_branch, reflog_head,
> +				   reflog_orig_head, default_reflog_action,
> +				   flags);
>  
>  	action = reset_hard ? "reset" : "checkout";
>  	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
> @@ -90,49 +141,10 @@ int reset_head(struct repository *r, struct object_id *oid,
>  		goto leave_reset_head;
>  	}
>  
> -reset_head_refs:
> -	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
> -	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
> -	prefix_len = msg.len;
> -
> -	if (update_orig_head) {
> -		if (!get_oid("ORIG_HEAD", &oid_old_orig))
> -			old_orig = &oid_old_orig;
> -		if (!get_oid("HEAD", &oid_orig)) {
> -			orig = &oid_orig;
> -			if (!reflog_orig_head) {
> -				strbuf_addstr(&msg, "updating ORIG_HEAD");
> -				reflog_orig_head = msg.buf;
> -			}
> -			update_ref(reflog_orig_head, "ORIG_HEAD", orig,
> -				   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
> -		} else if (old_orig)
> -			delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
> -	}
> -
> -	if (!reflog_head) {
> -		strbuf_setlen(&msg, prefix_len);
> -		strbuf_addstr(&msg, "updating HEAD");
> -		reflog_head = msg.buf;
> -	}
> -	if (!switch_to_branch)
> -		ret = update_ref(reflog_head, "HEAD", oid, orig,
> -				 detach_head ? REF_NO_DEREF : 0,
> -				 UPDATE_REFS_MSG_ON_ERR);
> -	else {
> -		ret = update_ref(reflog_head, switch_to_branch, oid,
> -				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
> -		if (!ret)
> -			ret = create_symref("HEAD", switch_to_branch,
> -					    reflog_head);
> -	}
> -	if (!ret && run_hook)
> -		run_hook_le(NULL, "post-checkout",
> -			    oid_to_hex(orig ? orig : null_oid()),
> -			    oid_to_hex(oid), "1", NULL);
> +	ret = update_refs(oid, switch_to_branch, reflog_head, reflog_orig_head,
> +			  default_reflog_action, flags);
>  
>  leave_reset_head:
> -	strbuf_release(&msg);
>  	rollback_lock_file(&lock);
>  	clear_unpack_trees_porcelain(&unpack_tree_opts);
>  	while (nr)