The ll_binary_merge() function assumes that the ancestor blob is
different from either side of the new versions, and always fails
the merge in conflict, unless -Xours or -Xtheirs is in effect.
The normal "merge" machineries all resolve the trivial cases
(e.g. if our side changed while their side did not, the result
is ours) without triggering the file-level merge drivers, so the
assumption is warranted.
The code path in "git apply --3way", however, does not check for
the trivial three-way merge situation and always calls the
file-level merge drivers. This used to be perfectly OK back
when we always first attempted a straight patch application and
used the three-way code path only as a fallback. Any binary
patch that can be applied as a trivial three-way merge (e.g. the
patch is based exactly on the version we happen to have) would
always cleanly apply, so the ll_binary_merge() that is not
prepared to see the trivial case would not have to handle such a
case.
This no longer is true after we made "--3way" to mean "first try
three-way and then fall back to straight application", and made
"git apply -3" on a binary patch that is based on the current
version no longer apply.
Teach "git apply -3" to first check for the trivial merge cases
and resolve them without hitting the file-level merge drivers.
Signed-off-by: Jerry Zhang <jerry@skydio.com>
[jc: stolen tests from Jerry's patch]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git apply" does not allow "--cached" and "--3way" to be used
together, since "--3way" writes conflict markers into the working
tree.
Allow "git apply" to accept "--cached" and "--3way" at the same
time. When a single file auto-resolves cleanly, the result is
placed in the index at stage #0 and the command exits with 0 status.
For a file that has a conflict which cannot be cleanly
auto-resolved, the original contents from common ancestor (stage
conflict at the content level, and the command exists with non-zero
status, because there is no place (like the working tree) to leave a
half-resolved merge for the user to resolve.
The user can use `git diff` to view the contents of the conflict, or
`git checkout -m -- .` to regenerate the conflict markers in the
working directory.
Don't attempt rerere in this case since it depends on conflict
markers written to file for its database storage and lookup. There
would be two main changes required to get rerere working:
1. Allow the rerere api to accept in memory object rather than
files, which would allow us to pass in the conflict markers
contained in the result from ll_merge().
2. Rerere can't write to the working directory, so it would have to
apply the result to cache stage #0 directly. A flag would be
needed to control this.
Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The apply_fragments() method of "git apply"
can silently apply patches incorrectly if
a file has repeating contents. In these
cases a three-way merge is capable of applying
it correctly in more situations, and will
show a conflict rather than applying it
incorrectly. However, because the patches
apply "successfully" using apply_fragments(),
git will never fall back to the merge, even
if the "--3way" flag is used, and the user has
no way to ensure correctness by forcing the
three-way merge method.
Change the behavior so that when "--3way" is used,
git will always try the three-way merge first and
will only fall back to apply_fragments() in cases
where blobs are not available or some other error
(but not in the case of a merge conflict).
Since user-facing results will be different,
this has backwards compatibility implications
for users depending on the old behavior. In
addition, the three-way merge will be slower
than direct patch application.
Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Carefully excluding t4013 and t4015, which see independent development
elsewhere at the time of writing, we use `main` as the default branch
name in t4*. This trick was performed via
$ (cd t &&
sed -i -e 's/master/main/g' -e 's/MASTER/MAIN/g' \
-e 's/Master/Main/g' -- t4*.sh t4211/*.export &&
git checkout HEAD -- t4013\*)
This allows us to define `GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main`
for those tests.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In addition to the manual adjustment to let the `linux-gcc` CI job run
the test suite with `master` and then with `main`, this patch makes sure
that GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME is set in all test scripts
that currently rely on the initial branch name being `master by default.
To determine which test scripts to mark up, the first step was to
force-set the default branch name to `master` in
- all test scripts that contain the keyword `master`,
- t4211, which expects `t/t4211/history.export` with a hard-coded ref to
initialize the default branch,
- t5560 because it sources `t/t556x_common` which uses `master`,
- t8002 and t8012 because both source `t/annotate-tests.sh` which also
uses `master`)
This trick was performed by this command:
$ sed -i '/^ *\. \.\/\(test-lib\|lib-\(bash\|cvs\|git-svn\)\|gitweb-lib\)\.sh$/i\
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
' $(git grep -l master t/t[0-9]*.sh) \
t/t4211*.sh t/t5560*.sh t/t8002*.sh t/t8012*.sh
After that, careful, manual inspection revealed that some of the test
scripts containing the needle `master` do not actually rely on a
specific default branch name: either they mention `master` only in a
comment, or they initialize that branch specificially, or they do not
actually refer to the current default branch. Therefore, the
aforementioned modification was undone in those test scripts thusly:
$ git checkout HEAD -- \
t/t0027-auto-crlf.sh t/t0060-path-utils.sh \
t/t1011-read-tree-sparse-checkout.sh \
t/t1305-config-include.sh t/t1309-early-config.sh \
t/t1402-check-ref-format.sh t/t1450-fsck.sh \
t/t2024-checkout-dwim.sh \
t/t2106-update-index-assume-unchanged.sh \
t/t3040-subprojects-basic.sh t/t3301-notes.sh \
t/t3308-notes-merge.sh t/t3423-rebase-reword.sh \
t/t3436-rebase-more-options.sh \
t/t4015-diff-whitespace.sh t/t4257-am-interactive.sh \
t/t5323-pack-redundant.sh t/t5401-update-hooks.sh \
t/t5511-refspec.sh t/t5526-fetch-submodules.sh \
t/t5529-push-errors.sh t/t5530-upload-pack-error.sh \
t/t5548-push-porcelain.sh \
t/t5552-skipping-fetch-negotiator.sh \
t/t5572-pull-submodule.sh t/t5608-clone-2gb.sh \
t/t5614-clone-submodules-shallow.sh \
t/t7508-status.sh t/t7606-merge-custom.sh \
t/t9302-fast-import-unpack-limit.sh
We excluded one set of test scripts in these commands, though: the range
of `git p4` tests. The reason? `git p4` stores the (foreign) remote
branch in the branch called `p4/master`, which is obviously not the
default branch. Manual analysis revealed that only five of these tests
actually require a specific default branch name to pass; They were
modified thusly:
$ sed -i '/^ *\. \.\/lib-git-p4\.sh$/i\
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
' t/t980[0167]*.sh t/t9811*.sh
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before, when doing a 3-way merge, the merge.conflictStyle option was not
respected and the "merge" style was always used, even if "diff3" was
specified.
Call git_xmerge_config() at the end of git_apply_config() so that the
merge.conflictStyle config is read.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, apply does not respect the merge.conflictStyle setting.
Demonstrate this by making the 'apply with --3way' test case generic and
extending it to show that the configuration of
merge.conflictStyle = diff3 causes a breakage.
Change print_sanitized_conflicted_diff() to also sanitize `|||||||`
conflict markers.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since `git config` leaves the configurations set even after the test
case completes, use `test_config` instead so that the configurations are
reset once the test case finishes.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before, the output of `git diff HEAD` would always be piped to
sanitize_conflicted_diff(). However, since the Git command was upstream
of the pipe, in case the Git command fails, the return code would be
lost. Rewrite into separate statements so that the return code is no
longer lost.
Since only the command `git diff HEAD` was being piped to
sanitize_conflicted_diff(), move the command into the function and rename
it to print_sanitized_conflicted_diff().
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the locally defined create_file() duplicates the functionality of
the test_write_lines() helper function, remove create_file() and replace
all instances with test_write_lines(). While we're at it, move
redirection operators to the end of the command which is the more
conventional place to put it.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now we have all the necessary logic to fall back on three-way merge when
the patch does not cleanly apply, insert the conflicted entries to the
index as appropriate. This obviously triggers only when the "--index"
option is used.
When we fall back to three-way merge and some of the merges fail, just
like the case where the "--reject" option was specified and we had to
write some "*.rej" files out for unapplicable patches, exit the command
with non-zero status without showing the diffstat and summary. Otherwise
they would make the list of problematic paths scroll off the display.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
