While it makes sense to allow merging unrelated histories of two
projects that started independently into one, in the way "gitk" was
merged to "git" itself aka "the coolest merge ever", such a merge is
still an unusual event. Worse, if somebody creates an independent
history by starting from a tarball of an established project and
sends a pull request to the original project, "git merge" however
happily creates such a merge without any sign of something unusual
is happening.
Teach "git merge" to refuse to create such a merge by default,
unless the user passes a new "--allow-unrelated-histories" option to
tell it that the user is aware that two unrelated projects are
merged.
Because such a "two project merge" is a rare event, a configuration
option to always allow such a merge is not added.
We could add the same option to "git pull" and have it passed
through to underlying "git merge". I do not have a fundamental
opposition against such a feature, but this commit does not do so
and instead leaves it as low-hanging fruit for others, because such
a "two project merge" would be done after fetching the other project
into some location in the working tree of an existing project and
making sure how well they fit together, it is sufficient to allow a
local merge without such an option pass-through from "git pull" to
"git merge". Many tests that are updated by this patch does the
pass-through manually by turning:
git pull something
into its equivalent:
git fetch something &&
git merge --allow-unrelated-histories FETCH_HEAD
If somebody is inclined to add such an option, updated tests in this
change need to be adjusted back to:
git pull --allow-unrelated-histories something
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Logic in still_interesting function allows to stop the commits
traversing if the oldest processed commit is not older then the
youngest commit on the list to process and the list contains only
commits marked as not interesting ones. It can be premature when dealing
with a set of coequal commits. For example git rev-list A^! --not B
provides wrong answer if all commits in the range A..B had the same
commit time and there are more then 7 of them.
To fix this problem the relevant part of the logic in still_interesting
is changed to: the walk can be stopped if the oldest processed commit is
younger then the youngest commit on the list to processed.
Signed-off-by: Kacper Kornet <draenog@pld-linux.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Unlike bash and ksh, dash and busybox ash do not support brace
expansion (as in 'echo {hello,world}'). So when dash is sh,
t6009.13 (set up dodecapus) ends up pass a string beginning with
"root{1,2," to "git merge" verbatim and the test fails.
Fix it by introducing a variable to hold the list of parents for
the dodecapus and populating it in a more low-tech way.
While at it, simplify a little by combining this setup code with the
test it sets up for.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This also adds test for "--merges" and "--no-merges" which we did not
have so far.
Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Breaks in a test assertion's && chain can potentially hide
failures from earlier commands in the chain.
Commands intended to fail should be marked with !, test_must_fail, or
test_might_fail. The examples in this patch do not require that.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The revision limiter uses the commit date to decide when it has seen
enough commits to finalize the revision list, but that can get confused
if there are incorrect dates far in the past on some commits.
This makes the logic a bit more robust by
- we always walk an extra SLOP commits from the source list even if we
decide that the source list is probably all done (unless the source is
entirely empty, of course, because then we really can't do anything at
all)
- we keep track of the date of the last commit we added to the
destination list (this will *generally* be the oldest entry we've seen
so far)
- we compare that with the youngest entry (the first one) of the source
list, and if the destination is older than the source, we know we want
to look at the source.
which causes occasional date mishaps to be handled cleanly.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many scripts compare actual and expected output using
"diff -u". This is nicer than "cmp" because the output shows
how the two differ. However, not all versions of diff
understand -u, leading to unnecessary test failure.
This adds a test_cmp function to the test scripts and
switches all "diff -u" invocations to use it. The function
uses the contents of "$GIT_TEST_CMP" to compare its
arguments; the default is "diff -u".
On systems with a less-capable diff, you can do:
GIT_TEST_CMP=cmp make test
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is the absolute minimum (and reliable) reproduction recipe
to demonstrate that revision range in a history with clock skew
sometimes fails to mark UNINTERESTING commit in topologically
early parts of the history.
The history looks like this:
o---o---o---o
one four
but one has the largest timestamp. "git rev-list four..one"
fails to notice that "one" should not be emitted.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
