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| author | Jonathan Tan <jonathantanmy@google.com> | 2019-01-10 11:36:45 -0800 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2019-01-10 14:53:35 -0800 |
| commit | bd0b42aed3084bf66557485fd7d87e975a4f6d4e (patch) | |
| tree | 3687936d9bd551986a68a23e665ec169e08194bd /fetch-pack.c | |
| parent | ecbdaf0899161c067986e9d9d564586d4b045d62 (diff) | |
| download | git-bd0b42aed3084bf66557485fd7d87e975a4f6d4e.tar.gz | |
fetch-pack: do not take shallow lock unnecessarily
When fetching using protocol v2, the remote may send a "shallow-info"
section if the client is shallow. If so, Git as the client currently
takes the shallow file lock, even if the "shallow-info" section is
empty.
This is not a problem except that Git does not support taking the
shallow file lock after modifying the shallow file, because
is_repository_shallow() stores information that is never cleared. And
this take-after-modify occurs when Git does a tag-following fetch from a
shallow repository on a transport that does not support tag following
(since in this case, 2 fetches are performed).
To solve this issue, take the shallow file lock (and perform all other
shallow processing) only if the "shallow-info" section is non-empty;
otherwise, behave as if it were empty.
A full solution (probably, ensuring that any action of committing
shallow file locks also includes clearing the information stored by
is_repository_shallow()) would solve the issue without need for this
patch, but this patch is independently useful (as an optimization to
prevent writing a file in an unnecessary case), hence why I wrote it. I
have included a NEEDSWORK outlining the full solution.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'fetch-pack.c')
| -rw-r--r-- | fetch-pack.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/fetch-pack.c b/fetch-pack.c index dd6700bda9..5885623ece 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -1232,6 +1232,8 @@ static int process_acks(struct fetch_negotiator *negotiator, static void receive_shallow_info(struct fetch_pack_args *args, struct packet_reader *reader) { + int line_received = 0; + process_section_header(reader, "shallow-info", 0); while (packet_reader_read(reader) == PACKET_READ_NORMAL) { const char *arg; @@ -1241,6 +1243,7 @@ static void receive_shallow_info(struct fetch_pack_args *args, if (get_oid_hex(arg, &oid)) die(_("invalid shallow line: %s"), reader->line); register_shallow(the_repository, &oid); + line_received = 1; continue; } if (skip_prefix(reader->line, "unshallow ", &arg)) { @@ -1253,6 +1256,7 @@ static void receive_shallow_info(struct fetch_pack_args *args, die(_("error in object: %s"), reader->line); if (unregister_shallow(&oid)) die(_("no shallow found: %s"), reader->line); + line_received = 1; continue; } die(_("expected shallow/unshallow, got %s"), reader->line); @@ -1262,8 +1266,11 @@ static void receive_shallow_info(struct fetch_pack_args *args, reader->status != PACKET_READ_DELIM) die(_("error processing shallow info: %d"), reader->status); - setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, NULL); - args->deepen = 1; + if (line_received) { + setup_alternate_shallow(&shallow_lock, &alternate_shallow_file, + NULL); + args->deepen = 1; + } } static void receive_wanted_refs(struct packet_reader *reader, |