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[PATCH v5 14/14] fetch-pack: restore save_commit_buffer after use

From
JHJeff Hostetler <git@jeffhostetler.com>
Date
Nov 21, 2017, 21:15 UTC
Message-ID
<20171121211528.21891-15-git@jeffhostetler.com>
In-Reply-To
<20171121211528.21891-1-git@jeffhostetler.com>
From: Jonathan Tan <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>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 fetch-pack.c | 4 ++++
 1 file changed, 4 insertions(+)
diff --git a/fetch-pack.c b/fetch-pack.c
index 2b04251..33a36d1 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -717,6 +717,7 @@ 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;
@@ -784,6 +785,9 @@ 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;
 }
 
-- 
2.9.3
Previous: Jeff HostetlerNext: Jeff Hostetler
Message 12 of 15 in “Parial clone part 3: clone, fetch, fetch-pack, upload-pack, and tests”
  1. 00/14 Parial clone part 3: clone, fetch, fetch-pack, upload-pack, and testsJeff Hostetler, Nov 21, 2017
  2. 01/14 upload-pack: add object filtering for partial cloneJeff Hostetler, Nov 21, 2017
  3. 04/14 fetch: add object filtering for partial fetchJeff Hostetler, Nov 21, 2017
  4. 09/14 fetch: add from_promisor and exclude-promisor-objects parametersJeff Hostetler, Nov 21, 2017
  5. 06/14 pack-objects: test support for blob filteringJeff Hostetler, Nov 21, 2017
  6. 05/14 remote-curl: add object filtering for partial cloneJeff Hostetler, Nov 21, 2017
  7. 07/14 fetch-pack: test support excluding large blobsJeff Hostetler, Nov 21, 2017
  8. 08/14 partial-clone: define partial clone settings in configJeff Hostetler, Nov 21, 2017
  9. 10/14 t5500: add fetch-pack tests for partial cloneJeff Hostetler, Nov 21, 2017
  10. 12/14 t5500: more tests for partial clone and fetchJeff Hostetler, Nov 21, 2017
  11. 11/14 t5601: test for partial cloneJeff Hostetler, Nov 21, 2017
  12. 14/14 fetch-pack: restore save_commit_buffer after useJeff Hostetler, Nov 21, 2017
  13. 13/14 unpack-trees: batch fetching of missing blobsJeff Hostetler, Nov 21, 2017
  14. 02/14 clone, fetch-pack, index-pack, transport: partial cloneJeff Hostetler, Nov 21, 2017
  15. 03/14 fetch: refactor calculation of remote listJeff Hostetler, Nov 21, 2017

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