The commit-graph feature has seen a lot of activity in the past
year or so since it was introduced. The feature is a critical
performance enhancement for medium- to large-sized repos, and
does not significantly hurt small repos.
Change the defaults for core.commitGraph and gc.writeCommitGraph
to true so users benefit from this feature by default.
There are several places in the test suite where the environment
variable GIT_TEST_COMMIT_GRAPH is disabled to avoid reading a
commit-graph, if it exists. The config option overrides the
environment, so swap these. Some GIT_TEST_COMMIT_GRAPH assignments
remain, and those are to avoid writing a commit-graph when a new
commit is created.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit-graph feature is tested in isolation by
t5318-commit-graph.sh and t6600-test-reach.sh, but there are many
more interesting scenarios involving commit walks. Many of these
scenarios are covered by the existing test suite, but we need to
maintain coverage when the optional commit-graph structure is not
present.
To allow running the full test suite with the commit-graph present,
add a new test environment variable, GIT_TEST_COMMIT_GRAPH. Similar
to GIT_TEST_SPLIT_INDEX, this variable makes every Git command try
to load the commit-graph when parsing commits, and writes the
commit-graph file after every 'git commit' command.
There are a few tests that rely on commits not existing in
pack-files to trigger important events, so manually set
GIT_TEST_COMMIT_GRAPH to false for the necessary commands.
There is one test in t6024-recursive-merge.sh that relies on the
merge-base algorithm picking one of two ambiguous merge-bases, and
the commit-graph feature changes which merge-base is picked.
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cc0e6c5 (Handle return code of parse_commit in revision machinery,
2007-05-04) attempted to tighten error checking in the revision machinery,
but it wasn't enough. When get_revision_1() was asked for the next commit
to return, it tries to read and simplify the parents of the commit to be
returned, but an error while doing so was silently ignored and reported as
a truncated history to the caller instead.
This resulted in an early end of "git log" output or a pack that lacks
older commits from "git pack-objects", without any error indication in the
exit status from these commands, even though the underlying parse_commit()
issues an error message to the end user.
Note that the codepath in add_parents_list() that paints parents of an
UNINTERESTING commit UNINTERESTING silently ignores the error when
parse_commit() fails; this is deliberate and in line with aeeae1b
(revision traversal: allow UNINTERESTING objects to be missing,
2009-01-27).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
