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From: Jonathan Tan <jonathantanmy@google.com>
To: git@vger.kernel.org
Cc: Jonathan Tan <jonathantanmy@google.com>,
	gitster@pobox.com, git@jeffhostetler.com, peartben@gmail.com,
	christian.couder@gmail.com
Subject: [PATCH 18/18] fetch-pack: restore save_commit_buffer after use
Date: Fri, 29 Sep 2017 13:11:54 -0700	[thread overview]
Message-ID: <b88725476d9f13ba4381d85e5fe049f6ef93f621.1506714999.git.jonathantanmy@google.com> (raw)
In-Reply-To: <cover.1506714999.git.jonathantanmy@google.com>
In-Reply-To: <cover.1506714999.git.jonathantanmy@google.com>

In fetch-pack, the global variable save_commit_buffer is set to 0, but
not restored to its original value after use.

In particular, if show_log() (in log-tree.c) is invoked after
fetch_pack() in the same process, show_log() will return before printing
out the commit message (because the invocation to
get_cached_commit_buffer() returns NULL, because the commit buffer was
not saved). I discovered this when attempting to run "git log -S" in a
partial clone, triggering the case where revision walking lazily loads
missing objects.

Therefore, restore save_commit_buffer to its original value after use.

An alternative to solve the problem I had is to replace
get_cached_commit_buffer() with get_commit_buffer(). That invocation was
introduced in commit a97934d ("use get_cached_commit_buffer where
appropriate", 2014-06-13) to replace "commit->buffer" introduced in
commit 3131b71 ("Add "--show-all" revision walker flag for debugging",
2008-02-13). In the latter commit, the commit author seems to be
deciding between not showing an unparsed commit at all and showing an
unparsed commit without the message (which is what the commit does), and
did not mention parsing the unparsed commit, so I prefer to preserve the
existing behavior.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 fetch-pack.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fetch-pack.c b/fetch-pack.c
index 19b8e9322..8e6f54547 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -719,6 +719,7 @@ static int everything_local(struct fetch_pack_args *args,
 {
 	struct ref *ref;
 	int retval;
+	int old_save_commit_buffer = save_commit_buffer;
 	timestamp_t cutoff = 0;
 
 	save_commit_buffer = 0;
@@ -786,6 +787,9 @@ static int everything_local(struct fetch_pack_args *args,
 		print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 			      ref->name);
 	}
+
+	save_commit_buffer = old_save_commit_buffer;
+
 	return retval;
 }
 
-- 
2.14.2.822.g60be5d43e6-goog


  parent reply	other threads:[~2017-09-29 20:12 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-29 20:11 [PATCH 00/18] Partial clone (from clone to lazy fetch in 18 patches) Jonathan Tan
2017-09-29 20:11 ` [PATCH 01/18] fsck: introduce partialclone extension Jonathan Tan
2017-09-29 20:11 ` [PATCH 02/18] fsck: support refs pointing to promisor objects Jonathan Tan
2017-09-29 20:11 ` [PATCH 03/18] fsck: support referenced " Jonathan Tan
2017-09-29 20:11 ` [PATCH 04/18] fsck: support promisor objects as CLI argument Jonathan Tan
2017-09-29 20:11 ` [PATCH 05/18] index-pack: refactor writing of .keep files Jonathan Tan
2017-09-29 20:11 ` [PATCH 06/18] introduce fetch-object: fetch one promisor object Jonathan Tan
2017-09-29 20:11 ` [PATCH 07/18] sha1_file: support lazily fetching missing objects Jonathan Tan
2017-10-12 14:42   ` Christian Couder
2017-10-12 15:45     ` Christian Couder
2017-09-29 20:11 ` [PATCH 08/18] rev-list: support termination at promisor objects Jonathan Tan
2017-09-29 20:11 ` [PATCH 09/18] gc: do not repack promisor packfiles Jonathan Tan
2017-09-29 20:11 ` [PATCH 10/18] pack-objects: rename want_.* to ignore_.* Jonathan Tan
2017-09-29 20:11 ` [PATCH 11/18] pack-objects: support --blob-max-bytes Jonathan Tan
2017-09-29 20:11 ` [PATCH 12/18] fetch-pack: support excluding large blobs Jonathan Tan
2017-09-29 20:11 ` [PATCH 13/18] fetch: refactor calculation of remote list Jonathan Tan
2017-09-29 20:11 ` [PATCH 14/18] fetch: support excluding large blobs Jonathan Tan
2017-09-29 20:11 ` [PATCH 15/18] clone: " Jonathan Tan
2017-09-29 20:11 ` [PATCH 16/18] clone: configure blobmaxbytes in created repos Jonathan Tan
2017-09-29 20:11 ` [PATCH 17/18] unpack-trees: batch fetching of missing blobs Jonathan Tan
2017-09-29 20:11 ` Jonathan Tan [this message]
2017-09-29 21:08 ` [PATCH 00/18] Partial clone (from clone to lazy fetch in 18 patches) Johannes Schindelin
2017-10-02  4:23 ` Junio C Hamano
2017-10-03  6:15 ` Christian Couder
2017-10-03  8:50   ` Junio C Hamano
2017-10-03 14:39     ` Jeff Hostetler
2017-10-03 23:42       ` Jonathan Tan
2017-10-04 13:30         ` Jeff Hostetler

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