The -L option is documented to accept no pathspec, but the
command line option parser has allowed the combination without
checking so far. Ensure that there is no pathspec when the -L
option is in effect to fix this.
Incidentally, this change fixes another bug in the command line
option parser, which has allowed the -L option used together
with the --follow option. Because the latter requires exactly
one path given, but the former takes no pathspec, they become
mutually incompatible automatically. Because the -L option
follows renames on its own, there is no reason to give --follow
at the same time.
The new tests say they may fail with "-L and --follow being
incompatible" instead of "-L and pathspec being incompatible".
Currently the expected failure can come only from the latter, but
this is to futureproof them, in case we decide to add code to
explicititly die on -L and --follow used together.
Heled-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that we call test_oid_init in the setup for all test scripts,
there's no point in calling it individually. Remove all of the places
where we've done so to help keep tests tidy.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If one of the options --before, --min-age or --until is given,
limit_list() filters out younger commits early on. Line-log needs all
those commits to trace the movement of line ranges, though. Skip this
optimization if both are used together.
Reported-by: Мария Долгополова <dolgopolovamariia@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current line-level log implementation performs a preprocessing
step in prepare_revision_walk(), during which the line_log_filter()
function filters and rewrites history to keep only commits modifying
the given line range. This preprocessing affects both responsiveness
and correctness:
- Git doesn't produce any output during this preprocessing step.
Checking whether a commit modified the given line range is
somewhat expensive, so depending on the size of the given revision
range this preprocessing can result in a significant delay before
the first commit is shown.
- Limiting the number of displayed commits (e.g. 'git log -3 -L...')
doesn't limit the amount of work during preprocessing, because
that limit is applied during history traversal. Alas, by that
point this expensive preprocessing step has already churned
through the whole revision range to find all commits modifying the
revision range, even though only a few of them need to be shown.
- It rewrites parents, with no way to turn it off. Without the user
explicitly requesting parent rewriting any parent object ID shown
should be that of the immediate parent, just like in case of a
pathspec-limited history traversal without parent rewriting.
However, after that preprocessing step rewrote history, the
subsequent "regular" history traversal (i.e. get_revision() in a
loop) only sees commits modifying the given line range.
Consequently, it can only show the object ID of the last ancestor
that modified the given line range (which might happen to be the
immediate parent, but many-many times it isn't).
This patch addresses both the correctness and, at least for the common
case, the responsiveness issues by integrating line-level log
filtering into the regular revision walking machinery:
- Make process_ranges_arbitrary_commit(), the static function in
'line-log.c' deciding whether a commit modifies the given line
range, public by removing the static keyword and adding the
'line_log_' prefix, so it can be called from other parts of the
revision walking machinery.
- If the user didn't explicitly ask for parent rewriting (which, I
believe, is the most common case):
- Call this now-public function during regular history traversal,
namely from get_commit_action() to ignore any commits not
modifying the given line range.
Note that while this check is relatively expensive, it must be
performed before other, much cheaper conditions, because the
tracked line range must be adjusted even when the commit will
end up being ignored by other conditions.
- Skip the line_log_filter() call, i.e. the expensive
preprocessing step, in prepare_revision_walk(), because, thanks
to the above points, the revision walking machinery is now able
to filter out commits not modifying the given line range while
traversing history.
This way the regular history traversal sees the unmodified
history, and is therefore able to print the object ids of the
immediate parents of the listed commits. The eliminated
preprocessing step can greatly reduce the delay before the first
commit is shown, see the numbers below.
- However, if the user did explicitly ask for parent rewriting via
'--parents' or a similar option, then stick with the current
implementation for now, i.e. perform that expensive filtering and
history rewriting in the preprocessing step just like we did
before, leaving the initial delay as long as it was.
I tried to integrate line-level log filtering with parent rewriting
into the regular history traversal, but, unfortunately, several
subtleties resisted... :) Maybe someday we'll figure out how to do
that, but until then at least the simple and common (i.e. without
parent rewriting) 'git log -L:func:file' commands can benefit from the
reduced delay.
This change makes the failing 'parent oids without parent rewriting'
test in 't4211-line-log.sh' succeed.
The reduced delay is most noticable when there's a commit modifying
the line range near the tip of a large-ish revision range:
# no parent rewriting requested, no commit-graph present
$ time git --no-pager log -L:read_alternate_refs:sha1-file.c -1 v2.23.0
Before:
real 0m9.570s
user 0m9.494s
sys 0m0.076s
After:
real 0m0.718s
user 0m0.674s
sys 0m0.044s
A significant part of the remaining delay is spent reading and parsing
commit objects in limit_list(). With the help of the commit-graph we
can eliminate most of that reading and parsing overhead, so here are
the timing results of the same command as above, but this time using
the commit-graph:
Before:
real 0m8.874s
user 0m8.816s
sys 0m0.057s
After:
real 0m0.107s
user 0m0.091s
sys 0m0.013s
The next patch will further reduce the remaining delay.
To be clear: this patch doesn't actually optimize the line-level log,
but merely moves most of the work from the preprocessing step to the
history traversal, so the commits modifying the line range can be
shown as soon as they are processed, and the traversal can be
terminated as soon as the given number of commits are shown.
Consequently, listing the full history of a line range, potentially
all the way to the root commit, will take the same time as before (but
at least the user might start reading the output earlier).
Furthermore, if the most recent commit modifying the line range is far
away from the starting revision, then that initial delay will still be
significant.
Additional testing by Derrick Stolee: In the Linux kernel repository,
the MAINTAINERS file was changed ~3,500 times across the ~915,000
commits. In addition to that edit frequency, the file itself is quite
large (~18,700 lines). This means that a significant portion of the
computation is taken up by computing the patch-diff of the file. This
patch improves the real time it takes to output the first result quite
a bit:
Command: git log -L 100,200:MAINTAINERS -n 1 >/dev/null
Before: 3.88 s
After: 0.71 s
If we drop the "-n 1" in the command, then there is no change in
end-to-end process time. This is because the command still needs to
walk the entire commit history, which negates the point of this
patch. This is expected.
As a note for future reference, the ~4.3 seconds in the old code
spends ~2.6 seconds computing the patch-diffs, and the rest of the
time is spent walking commits and computing diffs for which paths
changed at each commit. The changed-path Bloom filters could improve
the end-to-end computation time (i.e. no "-n 1" in the command).
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
None of the tests in 't4211-line-log.sh' really check which parent
object IDs are shown in the output, either implicitly as part of
"Merge: ..." lines [1] or explicitly via the '%p' or '%P' format
specifiers in a custom pretty format.
Add two tests to 't4211-line-log.sh' to check which parent object IDs
are shown, one without and one with explicitly requested parent
rewriting, IOW without and with the '--parents' option.
The test without '--parents' is marked as failing, because without
that option parent rewriting should not be performed, and thus the
parent object ID should be that of the immediate parent, just like in
case of a pathspec-limited history traversal without parent rewriting.
The current line-level log implementation, however, performs parent
rewriting unconditionally and without a possibility to turn it off,
and, consequently, it shows the object ID of the most recent ancestor
that modified the given line range.
In both of these new tests we only really care about the object IDs of
the listed commits and their parents, but not the diffs of the line
ranges; the diffs have already been thoroughly checked in the previous
tests.
[1] While one of the tests ('-M -L ':f:b.c' parallel-change') does
list a merge commit, both of its parents happen to modify the
given line range and are listed as well, so the implications of
parent rewriting remained hidden and untested.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are already files containing example output for SHA-1. Add test
files providing example output for SHA-256 as well and adjust the test
to look up the appropriate ones based on the algorithm in use.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In preparation for adding SHA-256 support to this test, let's move the
SHA-1-specific expected output into a directory called "sha1". This
will allow us to add a similar directory for SHA-256 as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With rename detection enabled the line-level log is able to trace the
evolution of line ranges across whole-file renames [1]. Alas, to
achieve that it uses the diff machinery very inefficiently, making the
operation very slow [2]. And since rename detection is enabled by
default, the line-level log is very slow by default.
When the line-level log processes a commit with rename detection
enabled, it currently does the following (see queue_diffs()):
1. Computes a full tree diff between the commit and (one of) its
parent(s), i.e. invokes diff_tree_oid() with an empty
'diffopt->pathspec'.
2. Checks whether any paths in the line ranges were modified.
3. Checks whether any modified paths in the line ranges are missing
in the parent commit's tree.
4. If there is such a missing path, then calls diffcore_std() to
figure out whether the path was indeed renamed based on the
previously computed full tree diff.
5. Continues doing stuff that are unrelated to the slowness.
So basically the line-level log computes a full tree diff for each
commit-parent pair in step (1) to be used for rename detection in step
(4) in the off chance that an interesting path is missing from the
parent.
Avoid these expensive and mostly unnecessary full tree diffs by
limiting the diffs to paths in the line ranges. This is much cheaper,
and makes step (2) unnecessary. If it turns out that an interesting
path is missing from the parent, then fall back and compute a full
tree diff, so the rename detection will still work.
Care must be taken when to update the pathspec used to limit the diff
in case of renames. A path might be renamed on one branch and
modified on several parallel running branches, and while processing
commits on these branches the line-level log might have to alternate
between looking at a path's new and old name. However, at any one
time there is only a single 'diffopt->pathspec'.
So add a step (0) to the above to ensure that the paths in the
pathspec match the paths in the line ranges associated with the
currently processed commit, and re-parse the pathspec from the paths
in the line ranges if they differ.
The new test cases include a specially crafted piece of history with
two merged branches and two files, where each branch modifies both
files, renames on of them, and then modifies both again. Then two
separate 'git log -L' invocations check the line-level log of each of
those two files, which ensures that at least one of those invocations
have to do that back-and-forth between the file's old and new name (no
matter which branch is traversed first). 't/t4211-line-log.sh'
already contains two tests involving renames, they don't don't trigger
this back-and-forth.
Avoiding these unnecessary full tree diffs can have huge impact on
performance, especially in big repositories with big trees and mergy
history. Tracing the evolution of a function through the whole
history:
# git.git
$ time git --no-pager log -L:read_alternate_refs:sha1-file.c v2.23.0
Before:
real 0m8.874s
user 0m8.816s
sys 0m0.057s
After:
real 0m2.516s
user 0m2.456s
sys 0m0.060s
# linux.git
$ time ~/src/git/git --no-pager log \
-L:build_restore_work_registers:arch/mips/mm/tlbex.c v5.2
Before:
real 3m50.033s
user 3m48.041s
sys 0m0.300s
After:
real 0m2.599s
user 0m2.466s
sys 0m0.157s
That's just over 88x speedup.
[1] Line-level log's rename following is quite similar to 'git log
--follow path', with the notable differences that it does handle
multiple paths at once as well, and that it doesn't show the
commit performing the rename if it's an exact rename.
[2] This slowness might not have been apparent initially, because back
when the line-level log feature was introduced rename detection
was not yet enabled by default; 12da1d1f6f (Implement line-history
search (git log -L), 2013-03-28) and 5404c116aa (diff: activate
diff.renames by default, 2016-02-25).
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you use "log -L" with an output format like "--raw" or "--stat",
we'll silently ignore the format and just output the normal patch.
Let's detect and complain about this, which at least tells the user
what's going on.
The tests here aren't exhaustive over the set of all formats, but it
should at least let us know if somebody breaks the format-checking.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When "-L" is in use, we ignore any diff output format that the user
provides to us, and just always print a patch (with extra context lines
covering the whole area of interest). It's not entirely clear what we
should do with all formats (e.g., should "--stat" show just the diffstat
of the touched lines, or the stat for the whole file?).
But "-s" is pretty clear: the user probably wants to see just the
commits that touched those lines, without any diff at all. Let's at
least make that work.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce optname() that does the early half of original opterror() to
come up with the name of the option reported back to the user, and use
it to kill opterror(). The callers of opterror() now directly call
error() using the string returned by opterror() instead.
There are a few issues with opterror()
- it tries to assemble an English sentence from pieces. This is not
great for translators because we give them pieces instead of a full
sentence.
- It's a wrapper around error() and needs some hack to let the
compiler know it always returns -1.
- Since it takes a string instead of printf format, one call site has
to assemble the string manually before passing to it.
Using error() directly solves the second and third problems.
It kind helps the first problem as well because "%s does foo" does
give a translator a full sentence in a sense and let them reorder if
needed. But it has limitations, if the subject part has to change
based on the rest of the sentence, that language is screwed. This is
also why I try to avoid calling optname() when 'flags' is known in
advance.
Mark of these strings for translation as well while at there.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test fixes.
* sg/test-must-be-empty:
tests: use 'test_must_be_empty' instead of 'test_cmp <empty> <out>'
tests: use 'test_must_be_empty' instead of 'test_cmp /dev/null <out>'
tests: use 'test_must_be_empty' instead of 'test ! -s'
tests: use 'test_must_be_empty' instead of '! test -s'
Using 'test_must_be_empty' is preferable to 'test ! -s', because it
gives a helpful error message if the given file is unexpectedly no
empty, while the latter remains completely silent. Furthermore, it
also catches cases when the given file unexpectedly does not exist at
all.
This patch was created by:
sed -i -e 's/test ! -s/test_must_be_empty/' t[0-9]*.sh
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the -L option is used to specify a line range in git log, and the end
of the range is past the end of the file, git will fail with a fatal
error. This commit prevents such behaviour - instead we perform the log
for existing lines within the specified range.
This commit also fixes a corner case where -L ,-n:file would be treated
as a log over the whole file. Now we treat this as -L 1,-n:file and
blame the first line of the file instead.
Signed-off-by: Isabella Stephens <istephens@atlassian.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The existing implementation of range_set_union does not correctly
reallocate memory, leading to a heap overflow when it attempts to union
more than 24 separate line ranges.
For struct range_set *out to grow correctly it must have out->nr set to
the current size of the buffer when it is passed to range_set_grow.
However, the existing implementation of range_set_union only updates
out->nr at the end of the function, meaning that it is always zero
before this. This results in range_set_grow never growing the buffer, as
well as some of the union logic itself being incorrect as !out->nr is
always true.
The reason why 24 is the limit is that the first allocation of size 1
ends up allocating a buffer of size 24 (due to the call to alloc_nr in
ALLOC_GROW). This goes some way to explain why this hasn't been
caught before.
Fix the problem by correctly updating out->nr after reallocating the
range_set. As this results in out->nr containing the same value as the
variable o, replace o with out->nr as well.
Finally, add a new test to help prevent the problem reoccurring in the
future. Thanks to Vegard Nossum for writing the test.
Signed-off-by: Allan Xavier <allan.x.xavier@oracle.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The test script t4202-log.sh is already pretty long, and it is a good
idea to test --output with a more obscure option, anyway. So let's
test it in conjunction with line-log.
The most important part of this test, of course, is to ensure that the
file is not closed after writing the diff, but only at the very end
of the log output. That is the entire reason why the test tries to
generate a log that covers more than one commit.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The old message did not mention the :regex:file form.
To avoid overly long lines, split the message into two lines (in case
item->string is long, it will be the only part truncated in a narrow
terminal).
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
line-log tries to access all parents of a commit, but only the first
parent has been loaded if "--first-parent" is specified, resulting
in a crash.
Limit the number of parents to one if "--first-parent" is specified.
Reported-by: Eric N. Vander Weele <ericvw@gmail.com>
Signed-off-by: Tzvetan Mikov <tmikov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The -L:RE option of blame/log searches from the end of the previous -L
range, if any. Add new notation -L^:RE to override this behavior and
search from start of file.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For consistency with -L/RE/, teach -L:RE to search relative to the end
of the previous -L range, if any.
The new behavior invalidates one test in t4211 which assumes that -L:RE
begins searching at start of file. This test will be resurrected in a
follow-up patch which teaches -L:RE how to override the default relative
search behavior.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When 12da1d1f added -L support to git-log, a broken bounds check was
copied from git-blame -L which incorrectly allows -LX to extend one line
past end of file without reporting an error. Instead, it generates an
empty range. Fix this bug.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
58960978 and 99780b0a added tests which demonstrated bugs (crashes) in
range-set and line-log when handed empty ranges specified via "log
-LX:file" where X is one greater than the last line of the file. After
these tests were added, it was realized that the ability to specify an
empty range is a loophole due to a bug in -L bounds checking. That bug
is slated to be fixed in a subsequent patch.
Unfortunately, the closure of this loophole makes it impossible to
continue checking range-set and line-log behavior with regard to empty
ranges since there is no other way to specify empty ranges via the
command-line. APIs of both facilities are private (file static) so
there likewise is no way to test their behaviors programmatically.
Consequently, retire these two tests.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A bounds checking bug allows the X in -LX to extend one line past the
end of file. For example, given a file with 5 lines, -L6 is accepted as
valid. Demonstrate this problem.
While here, also add tests to check that the remaining cases of X and Y
in -LX,Y are handled correctly at and in the vicinity of end-of-file.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Wnen I rewrote "cat b.c | wc -l" into "wc -l <b.c" to squash in a
suggestion on the list to this series, I screwed up subsequent
rebase. Fix it up.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
range-set invariants are: ranges must be (1) non-empty, (2) disjoint,
(3) sorted in ascending order.
line_log_data_insert() breaks the non-empty invariant under the
following conditions: the incoming range is empty and the pathname
attached to the range has not yet been encountered. In this case,
line_log_data_insert() assigns the empty range to a new line_log_data
record without taking any action to ensure that the empty range is
eventually folded out. Subsequent range-set functions crash or throw an
assertion failure upon encountering such an anomaly. Fix this bug.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Acked-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
range-set invariants are: ranges must be (1) non-empty, (2) disjoint,
(3) sorted in ascending order.
During processing, various range-set utility functions break the
invariants (for instance, by adding empty ranges), with the
expectation that a finalizing sort_and_merge_range_set() will restore
sanity.
sort_and_merge_range_set(), however, neglects to fold out empty
ranges, thus it fails to satisfy the non-empty constraint. Subsequent
range-set functions crash or throw an assertion failure upon
encountering such an anomaly. Rectify the situation by having
sort_and_merge_range_set() fold out empty ranges.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Acked-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Acked-by: Thomas Rast <trast@inf.ethz.ch>
Helped-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Acked-by: Thomas Rast <trast@inf.ethz.ch>
Helped-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When coalescing ranges, sort_and_merge_range_set() unconditionally
assumes that the end of a range being folded into a preceding range
should become the end of the coalesced range. This assumption, however,
is invalid when one range is a subset of another. For example, given
ranges 1-5 and 2-3 added via range_set_append_unsafe(),
sort_and_merge_range_set() incorrectly coalesces them to range 1-3
rather than the correct union range 1-5. Fix this bug.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4211 attempts to test multiple git-log -L ranges where one range is a
superset of the other, and falsely succeeds because its "expected"
output is incorrect.
Overlapping -L ranges handed to git-log are coalesced by
line-log.c:sort_and_merge_range_set() into a set of non-overlapping,
disjoint ranges. When one range is a subset of another,
sort_and_merge_range_set() should coalesce both ranges to the superset
range, but instead the coalesced range often is incorrectly truncated to
the end of the subset range. For example, ranges 2-8 and 3-4 are
coalesced incorrectly to 2-4.
One can observe this incorrect behavior with git-log -L using the test
repository created by t4211. The superset/subset ranges t4211 employs
are 4-$ and 8-12 (where $ represents end-of-file). The coalesced range
should be 4-$. Manually invoking git-log with the same ranges the test
employs, we see:
% git log -L 4:a.c simple |
awk '/^commit [0-9a-f]{40}/ { print substr($2,1,7) }'
4659538
100b61a
39b6eb2
a6eb826
f04fb20
de4c48a
% git log -L 8,12:a.c simple | awk ...
f04fb20
de4c48a
% git log -L 4:a.c -L 8,12:a.c simple | awk ...
a6eb826
f04fb20
de4c48a
This last output is incorrect. 8-12 is a subset of 4-$, hence the output
of the coalesced range should be the same as the 4-$ output shown first.
In fact, the above incorrect output is the truncated bogus range 4-12:
% git log -L 4,12:a.c simple | awk ...
a6eb826
f04fb20
de4c48a
Fix the test to correctly fail in the presence of the
sort_and_merge_range_set() coalescing bug. Do so by changing the
"expected" output to the commits mentioned in the 4-$ output above.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
line_log_data has held a diff_filespec* since the very early versions
of the code. However, the only place in the code where we actually
need the full filespec is parse_range_arg(); in all other cases, we
are only interested in the path, so there is hardly a reason to store
a filespec. Even worse, it causes a lot of redundant ->spec->path
pointer dereferencing.
And *even* worse, it caused the following bug. If you merge a rename
with a modification to the old filename, like so:
* Merge
| \
| * Modify foo
| |
* | Rename foo->bar
| /
* Create foo
we internally -- in process_ranges_merge_commit() -- scan all parents.
We are mainly looking for one that doesn't have any modifications, so
that we can assign all the blame to it and simplify away the merge.
In doing so, we run the normal machinery on all parents in a loop.
For each parent, we prepare a "working set" line_log_data by making a
copy with line_log_data_copy(), which does *not* make a copy of the
spec.
Now suppose the rename is the first parent. The diff machinery tells
us that the filepair is ('foo', 'bar'). We duly update the path we
are interested in:
rg->spec->path = xstrdup(pair->one->path);
But that 'struct spec' is shared between the output line_log_data and
the original input line_log_data. So we just wrecked the state of
process_ranges_merge_commit(). When we get around to the second
parent, the ranges tell us we are interested in a file 'foo' while the
commits touch 'bar'.
So most of this patch is just s/->spec->path/->path/ and associated
management changes. This implicitly fixes the bug because we removed
the shared parts between input and output of line_log_data_copy(); it
is now safe to overwrite the path in the copy.
There's one only somewhat related change: the comment in
process_all_files() explains the reasoning behind using 'range' there.
That bit of half-correct code had me sidetracked for a while.
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This tests a toy example of a history like
* Merge
| \
| * Modify foo
| |
* | Rename foo->bar
| /
* Create foo
Current log -L fails on this; we'll fix it in the next commit.
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Embarrassingly, the -M test did not actually invoke -M, and thus not
really test the feature.
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The existing code was too defensive, and would trigger the assert in
range_set_append() if the user gave overlapping ranges.
The intent was always to define overlapping ranges as just the union
of all of them, as evidenced by the call to sort_and_merge_range_set().
(Which was already used, unlike what the comment said.)
Fix by splitting out the meat of range_set_append() to a new _unsafe()
function that lacks the paranoia. sort_and_merge_range_set will fix
up the ranges, so we don't need the checks there.
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This new syntax finds a funcname matching /pattern/, and then takes from there
up to (but not including) the next funcname. So you can say
git log -L:main:main.c
and it will dig up the main() function and show its line-log, provided
there are no other funcnames matching 'main'.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a rewrite of much of Bo's work, mainly in an effort to split
it into smaller, easier to understand routines.
The algorithm is built around the struct range_set, which encodes a
series of line ranges as intervals [a,b). This is used in two
contexts:
* A set of lines we are tracking (which will change as we dig through
history).
* To encode diffs, as pairs of ranges.
The main routine is range_set_map_across_diff(). It processes the
diff between a commit C and some parent P. It determines which diff
hunks are relevant to the ranges tracked in C, and computes the new
ranges for P.
The algorithm is then simply to process history in topological order
from newest to oldest, computing ranges and (partial) diffs. At
branch points, we need to merge the ranges we are watching. We will
find that many commits do not affect the chosen ranges, and mark them
TREESAME (in addition to those already filtered by pathspec limiting).
Another pass of history simplification then gets rid of such commits.
This is wired as an extra filtering pass in the log machinery. This
currently only reduces code duplication, but should allow for other
simplifications and options to be used.
Finally, we hook a diff printer into the output chain. Ideally we
would wire directly into the diff logic, to optionally use features
like word diff. However, that will require some major reworking of
the diff chain, so we completely replace the output with our own diff
for now.
As this was a GSoC project, and has quite some history by now, many
people have helped. In no particular order, thanks go to
Jakub Narebski <jnareb@gmail.com>
Jens Lehmann <Jens.Lehmann@web.de>
Jonathan Nieder <jrnieder@gmail.com>
Junio C Hamano <gitster@pobox.com>
Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Will Palmer <wmpalmer@gmail.com>
Apologies to everyone I forgot.
Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano
brian m. carlson
René Scharfe
SZEDER Gábor
Jeff King
Nguyễn Thái Ngọc Duy
Isabella Stephens
Allan Xavier
Johannes Schindelin
Matthieu Moy
Tzvetan Mikov
Eric Sunshine
Thomas Rast
Thomas Rast