If you're going to access the contents of every object in a
packfile, it's generally much more efficient to do so in
pack order, rather than in hash order. That increases the
locality of access within the packfile, which in turn is
friendlier to the delta base cache, since the packfile puts
related deltas next to each other. By contrast, hash order
is effectively random, since the sha1 has no discernible
relationship to the content.
This patch introduces an "--unordered" option to cat-file
which iterates over packs in pack-order under the hood. You
can see the results when dumping all of the file content:
$ time ./git cat-file --batch-all-objects --buffer --batch | wc -c
6883195596
real 0m44.491s
user 0m42.902s
sys 0m5.230s
$ time ./git cat-file --unordered \
--batch-all-objects --buffer --batch | wc -c
6883195596
real 0m6.075s
user 0m4.774s
sys 0m3.548s
Same output, different order, way faster. The same speed-up
applies even if you end up accessing the object content in a
different process, like:
git cat-file --batch-all-objects --buffer --batch-check |
grep blob |
git cat-file --batch='%(objectname) %(rest)' |
wc -c
Adding "--unordered" to the first command drops the runtime
in git.git from 24s to 3.5s.
Side note: there are actually further speedups available
for doing it all in-process now. Since we are outputting
the object content during the actual pack iteration, we
know where to find the object and could skip the extra
lookup done by oid_object_info(). This patch stops short
of that optimization since the underlying API isn't ready
for us to make those sorts of direct requests.
So if --unordered is so much better, why not make it the
default? Two reasons:
1. We've promised in the documentation that --batch-all-objects
outputs in hash order. Since cat-file is plumbing,
people may be relying on that default, and we can't
change it.
2. It's actually _slower_ for some cases. We have to
compute the pack revindex to walk in pack order. And
our de-duplication step uses an oidset, rather than a
sort-and-dedup, which can end up being more expensive.
If we're just accessing the type and size of each
object, for example, like:
git cat-file --batch-all-objects --buffer --batch-check
my best-of-five warm cache timings go from 900ms to
1100ms using --unordered. Though it's possible in a
cold-cache or under memory pressure that we could do
better, since we'd have better locality within the
packfile.
And one final question: why is it "--unordered" and not
"--pack-order"? The answer is again two-fold:
1. "pack order" isn't a well-defined thing across the
whole set of objects. We're hitting loose objects, as
well as objects in multiple packs, and the only
ordering we're promising is _within_ a single pack. The
rest is apparently random.
2. The point here is optimization. So we don't want to
promise any particular ordering, but only to say that
we will choose an ordering which is likely to be
efficient for accessing the object content. That leaves
the door open for further changes in the future without
having to add another compatibility option.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a server-side knob to skip commits in exponential/fibbonacci
stride in an attempt to cover wider swath of history with a smaller
number of iterations, potentially accepting a larger packfile
transfer, instead of going back one commit a time during common
ancestor discovery during the "git fetch" transaction.
* jt/fetch-negotiator-skipping:
negotiator/skipping: skip commits during fetch
The recursive merge strategy did not properly ensure there was no
change between HEAD and the index before performing its operation,
which has been corrected.
* en/dirty-merge-fixes:
merge: fix misleading pre-merge check documentation
merge-recursive: enforce rule that index matches head before merging
t6044: add more testcases with staged changes before a merge is invoked
merge-recursive: fix assumption that head tree being merged is HEAD
merge-recursive: make sure when we say we abort that we actually abort
t6044: add a testcase for index matching head, when head doesn't match HEAD
t6044: verify that merges expected to abort actually abort
index_has_changes(): avoid assuming operating on the_index
read-cache.c: move index_has_changes() from merge.c
"git rebase --rebase-merges" mode now handles octopus merges as
well.
* js/rebase-merge-octopus:
rebase --rebase-merges: adjust man page for octopus support
rebase --rebase-merges: add support for octopus merges
merge: allow reading the merge commit message from a file
"git fetch" learned a new option "--negotiation-tip" to limit the
set of commits it tells the other end as "have", to reduce wasted
bandwidth and cycles, which would be helpful when the receiving
repository has a lot of refs that have little to do with the
history at the remote it is fetching from.
* jt/fetch-nego-tip:
fetch-pack: support negotiation tip whitelist
"git checkout" and "git worktree add" learned to honor
checkout.defaultRemote when auto-vivifying a local branch out of a
remote tracking branch in a repository with multiple remotes that
have tracking branches that share the same names.
* ab/checkout-default-remote:
checkout & worktree: introduce checkout.defaultRemote
checkout: add advice for ambiguous "checkout <branch>"
builtin/checkout.c: use "ret" variable for return
checkout: pass the "num_matches" up to callers
checkout.c: change "unique" member to "num_matches"
checkout.c: introduce an *_INIT macro
checkout.h: wrap the arguments to unique_tracking_name()
checkout tests: index should be clean after dwim checkout
"git diff --color-moved" feature has further been tweaked.
* sb/diff-color-move-more:
diff.c: offer config option to control ws handling in move detection
diff.c: add white space mode to move detection that allows indent changes
diff.c: factor advance_or_nullify out of mark_color_as_moved
diff.c: decouple white space treatment from move detection algorithm
diff.c: add a blocks mode for moved code detection
diff.c: adjust hash function signature to match hashmap expectation
diff.c: do not pass diff options as keydata to hashmap
t4015: avoid git as a pipe input
xdiff/xdiffi.c: remove unneeded function declarations
xdiff/xdiff.h: remove unused flags
"git fsck" learns to make sure the optional commit-graph file is in
a sane state.
* ds/commit-graph-fsck: (23 commits)
coccinelle: update commit.cocci
commit-graph: update design document
gc: automatically write commit-graph files
commit-graph: add '--reachable' option
commit-graph: use string-list API for input
fsck: verify commit-graph
commit-graph: verify contents match checksum
commit-graph: test for corrupted octopus edge
commit-graph: verify commit date
commit-graph: verify generation number
commit-graph: verify parent list
commit-graph: verify root tree OIDs
commit-graph: verify objects exist
commit-graph: verify corrupt OID fanout and lookup
commit-graph: verify required chunks are present
commit-graph: verify catches corrupt signature
commit-graph: add 'verify' subcommand
commit-graph: load a root tree from specific graph
commit: force commit to parse from object database
commit-graph: parse commit from chosen graph
...
"git rev-parse ':/substring'" did not consider the history leading
only to HEAD when looking for a commit with the given substring,
when the HEAD is detached. This has been fixed.
* wc/find-commit-with-pattern-on-detached-head:
sha1-name.c: for ":/", find detached HEAD commits
Partial clone support of "git clone" has been updated to correctly
validate the objects it receives from the other side. The server
side has been corrected to send objects that are directly
requested, even if they may match the filtering criteria (e.g. when
doing a "lazy blob" partial clone).
* jt/partial-clone-fsck-connectivity:
clone: check connectivity even if clone is partial
upload-pack: send refs' objects despite "filter"
The content-transfer-encoding of the message "git send-email" sends
out by default was 8bit, which can cause trouble when there is an
overlong line to bust RFC 5322/2822 limit. A new option 'auto' to
automatically switch to quoted-printable when there is such a line
in the payload has been introduced and is made the default.
* bc/send-email-auto-cte:
docs: correct RFC specifying email line length
send-email: automatically determine transfer-encoding
send-email: accept long lines with suitable transfer encoding
send-email: add an auto option for transfer encoding
"git fetch" failed to correctly validate the set of objects it
received when making a shallow history deeper, which has been
corrected.
* jt/connectivity-check-after-unshallow:
fetch-pack: write shallow, then check connectivity
fetch-pack: implement ref-in-want
fetch-pack: put shallow info in output parameter
fetch: refactor to make function args narrower
fetch: refactor fetch_refs into two functions
fetch: refactor the population of peer ref OIDs
upload-pack: test negotiation with changing repository
upload-pack: implement ref-in-want
test-pkt-line: add unpack-sideband subcommand
"git rebase" behaved slightly differently depending on which one of
the three backends gets used; this has been documented and an
effort to make them more uniform has begun.
* en/rebase-consistency:
git-rebase: make --allow-empty-message the default
t3401: add directory rename testcases for rebase and am
git-rebase.txt: document behavioral differences between modes
directory-rename-detection.txt: technical docs on abilities and limitations
git-rebase.txt: address confusion between --no-ff vs --force-rebase
git-rebase: error out when incompatible options passed
t3422: new testcases for checking when incompatible options passed
git-rebase.sh: update help messages a bit
git-rebase.txt: document incompatible options
The option of --color-moved has proven to be useful as observed on the
mailing list. However when refactoring sometimes the indentation changes,
for example when partitioning a functions into smaller helper functions
the code usually mostly moved around except for a decrease in indentation.
To just review the moved code ignoring the change in indentation, a mode
to ignore spaces in the move detection as implemented in a previous patch
would be enough. However the whole move coloring as motivated in commit
2e2d5ac (diff.c: color moved lines differently, 2017-06-30), brought
up the notion of the reviewer being able to trust the move of a "block".
As there are languages such as python, which depend on proper relative
indentation for the control flow of the program, ignoring any white space
change in a block would not uphold the promises of 2e2d5ac that allows
reviewers to pay less attention to the inside of a block, as inside
the reviewer wants to assume the same program flow.
This new mode of white space ignorance will take this into account and will
only allow the same white space changes per line in each block. This patch
even allows only for the same change at the beginning of the lines.
As this is a white space mode, it is made exclusive to other white space
modes in the move detection.
This patch brings some challenges, related to the detection of blocks.
We need a wide net to catch the possible moved lines, but then need to
narrow down to check if the blocks are still intact. Consider this
example (ignoring block sizes):
- A
- B
- C
+ A
+ B
+ C
At the beginning of a block when checking if there is a counterpart
for A, we have to ignore all space changes. However at the following
lines we have to check if the indent change stayed the same.
Checking if the indentation change did stay the same, is done by computing
the indentation change by the difference in line length, and then assume
the change is only in the beginning of the longer line, the common tail
is the same. That is why the test contains lines like:
- <TAB> A
...
+ A <TAB>
...
As the first line starting a block is caught using a compare function that
ignores white spaces unlike the rest of the block, where the white space
delta is taken into account for the comparison, we also have to think about
the following situation:
- A
- B
- A
- B
+ A
+ B
+ A
+ B
When checking if the first A (both in the + and - lines) is a start of
a block, we have to check all 'A' and record all the white space deltas
such that we can find the example above to be just one block that is
indented.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Clarify that setting core.ignoreCase to deviate from reality would
not turn a case-incapable filesystem into a case-capable one.
* ms/core-icase-doc:
Documentation: declare "core.ignoreCase" as internal variable
The "-l" option in "git branch -l" is an unfortunate short-hand for
"--create-reflog", but many users, both old and new, somehow expect
it to be something else, perhaps "--list". This step warns when "-l"
is used as a short-hand for "--create-reflog" and warns about the
future repurposing of the it when it is used.
* jk/branch-l-0-deprecation:
branch: deprecate "-l" option
t: switch "branch -l" to "branch --create-reflog"
t3200: unset core.logallrefupdates when testing reflog creation
"git grep" learned the "--column" option that gives not just the
line number but the column number of the hit.
* tb/grep-column:
contrib/git-jump/git-jump: jump to exact location
grep.c: add configuration variables to show matched option
builtin/grep.c: add '--column' option to 'git-grep(1)'
grep.c: display column number of first match
grep.[ch]: extend grep_opt to allow showing matched column
grep.c: expose {,inverted} match column in match_line()
Documentation/config.txt: camel-case lineNumber for consistency
In the original implementation of the move detection logic the choice for
ignoring white space changes is the same for the move detection as it is
for the regular diff. Some cases came up where different treatment would
have been nice.
Allow the user to specify that white space should be ignored differently
during detection of moved lines than during generation of added and removed
lines. This is done by providing analogs to the --ignore-space-at-eol,
-b, and -w options by introducing the option --color-moved-ws=<modes>
with the modes named "ignore-space-at-eol", "ignore-space-change" and
"ignore-all-space", which is used only during the move detection phase.
As we change the default, we'll adjust the tests.
For now we do not infer any options to treat white spaces in the move
detection from the generic white space options given to diff.
This can be tuned later to reasonable default.
As we plan on adding more white space related options in a later patch,
that interferes with the current white space options, use a flag field
and clamp it down to XDF_WHITESPACE_FLAGS, as that (a) allows to easily
check at parse time if we give invalid combinations and (b) can reuse
parts of this patch.
By having the white space treatment in its own option, we'll also
make it easier for a later patch to have an config option for
spaces in the move detection.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new "blocks" mode provides a middle ground between plain and zebra.
It is as intuitive (few colors) as plain, but still has the requirement
for a minimum of lines/characters to count a block as moved.
Suggested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
(https://public-inbox.org/git/87o9j0uljo.fsf@evledraar.gmail.com/)
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new negotiation algorithm used during fetch that skips
commits in an effort to find common ancestors faster. The skips grow
similarly to the Fibonacci sequence as the commit walk proceeds further
away from the tips. The skips may cause unnecessary commits to be
included in the packfile, but the negotiation step typically ends more
quickly.
Usage of this algorithm is guarded behind the configuration flag
fetch.negotiationAlgorithm.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch broadens the set of commits matched by ":/<pattern>" to
include commits reachable from HEAD but not any named ref. This avoids
surprising behavior when working with a detached HEAD and trying to
refer to a commit that was recently created and only exists within the
detached state.
If multiple worktrees exist, only the current worktree's HEAD is
considered reachable. This is consistent with the existing behavior for
other per-worktree refs: e.g., bisect refs are considered reachable, but
only within the relevant worktree.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: William Chargin <wchargin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that we support octopus merges in the `--rebase-merges` mode,
we should give users who actually read the manuals a chance to know
about this fact.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is consistent with `git commit` which, like `git merge`, supports
passing the commit message via `-m <msg>` and, unlike `git merge` before
this patch, via `-F <file>`.
It is useful to allow this for scripted use, or for the upcoming patch
to allow (re-)creating octopus merges in `git rebase --rebase-merges`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/merge.c contains this important requirement for merge strategies:
...the index must be in sync with the head commit. The strategies are
responsible to ensure this.
However, Documentation/git-merge.txt says:
...[merge will] abort if there are any changes registered in the index
relative to the `HEAD` commit. (One exception is when the changed
index entries are in the state that would result from the merge
already.)
Interestingly, prior to commit c0be8aa06b ("Documentation/git-merge.txt:
Partial rewrite of How Merge Works", 2008-07-19),
Documentation/git-merge.txt said much more:
...the index file must match the tree of `HEAD` commit...
[NOTE]
This is a bit of a lie. In certain special cases [explained
in detail]...
Otherwise, merge will refuse to do any harm to your repository
(that is...your working tree...and index are left intact).
So, this suggests that the exceptions existed because there were special
cases where it would case no harm, and potentially be slightly more
convenient for the user. While the current text in git-merge.txt does
list a condition under which it would be safe to proceed despite the index
not matching HEAD, it does not match what is actually implemented, in
three different ways:
* The exception is written to describe what unpack-trees allows. Not
all merge strategies allow such an exception, though, making this
description misleading. 'ours' and 'octopus' merges have strictly
enforced index==HEAD for a while, and the commit previous to this
one made 'recursive' do so as well.
* If someone did a three-way content merge on a specific file using
versions from the relevant commits and staged it prior to running
merge, then that path would technically satisfy the exception listed
in git-merge.txt. unpack-trees.c would still error out on the path,
though, because it defers the three-way content merge logic to other
parts of the code (resolve, octopus, or recursive) and has no way of
checking whether the index entry from before the merge will match
the end result of the merge.
* The exception as implemented in unpack-trees actually only checked
that the index matched the MERGE_HEAD version of the file and that
HEAD matched the merge base. Assuming no renames, that would indeed
provide cases where the index matches the end result we'd get from a
merge. But renames means unpack-trees is checking that it instead
matches something other than what the final result will be, risking
either erroring out when we shouldn't need to, or not erroring out
when we should and overwriting the user's staged changes.
In addition to the wording behind this exception being misleading, it is
also somewhat surprising to see how many times the code for the special
cases were wrong or the check to make sure the index matched head was
forgotten altogether:
* Prior to commit ee6566e8d7 ("[PATCH] Rewrite read-tree", 2005-09-05),
there were many cases where an unclean index entry was allowed (look for
merged_entry_allow_dirty()); it appears that in those cases, the merge
would have simply overwritten staged changes with the result of the
merge. Thus, the merge result would have been correct, but the user's
uncommitted changes could be thrown away without warning.
* Prior to commit 160252f816 ("git-merge-ours: make sure our index
matches HEAD", 2005-11-03), the 'ours' merge strategy did not check
whether the index matched HEAD. If it didn't, the resulting merge
would include all the staged changes, and thus wasn't really an 'ours'
strategy.
* Prior to commit 3ec62ad9ff ("merge-octopus: abort if index does not
match HEAD", 2016-04-09), 'octopus' merges did not check whether the
index matched HEAD, also resulting in any staged changes from before
the commit silently being folded into the resulting merge. commit
a6ee883b8e ("t6044: new merge testcases for when index doesn't match
HEAD", 2016-04-09) was also added at the same time to try to test to
make sure all strategies did the necessary checking for the requirement
that the index match HEAD. Sadly, it didn't catch all the cases, as
evidenced by the remainder of this list...
* Prior to commit 65170c07d4 ("merge-recursive: avoid incorporating
uncommitted changes in a merge", 2017-12-21), merge-recursive simply
relied on unpack_trees() to do the necessary check, but in one special
case it avoided calling unpack_trees() entirely and accidentally ended
up silently including any staged changes from before the merge in the
resulting merge commit.
* The commit immediately before this one in this series noted that the
exceptions were written in a way that assumed no renames, making it
unsafe for merge-recursive to use. merge-recursive was modified to
use its own check to enforce that index==HEAD.
This history makes it very tempting to go into builtin/merge.c and replace
the comment that strategies must enforce that index matches HEAD with code
that just enforces it. At this point, that would only affect the
'resolve' strategy; all other strategies have each been modified to
manually enforce it. (However, note that index==HEAD is not strictly
enforced for fast-forward merges, as those are not considered a merge
strategy and they trigger in builtin/merge.c before the section in the
code where the relevant comment is found.)
But, even if we don't take the step of just fixing these problems by
enforcing index==HEAD for all strategies, we at least need to update this
misleading documentation in git-merge.txt. For now, just modify the claim
in Documentation/git-merge.txt to fix the error. The precise details
around combination of merges strategies and special cases probably is not
relevant to most users, so simply state that exceptions may exist but are
narrow and vary depending upon which merge strategy is in use.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach 'git grep --only-matching', a new option to only print the
matching part(s) of a line.
For instance, a line containing the following (taken from README.md:27):
(`man gitcvs-migration` or `git help cvs-migration` if git is
Is printed as follows:
$ git grep --line-number --column --only-matching -e git -- \
README.md | grep ":27"
README.md:27:7:git
README.md:27:16:git
README.md:27:38:git
The patch works mostly as one would expect, with the exception of a few
considerations that are worth mentioning here.
Like GNU grep, this patch ignores --only-matching when --invert (-v) is
given. There is a sensible answer here, but parity with the behavior of
other tools is preferred.
Because a line might contain more than one match, there are special
considerations pertaining to when to print line headers, newlines, and
how to increment the match column offset. The line header and newlines
are handled as a special case within the main loop to avoid polluting
the surrounding code with conditionals that have large blocks.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A filter line in a request to upload-pack filters out objects regardless
of whether they are directly referenced by a "want" line or not. This
means that cloning with "--filter=blob:none" (or another filter that
excludes blobs) from a repository with at least one ref pointing to a
blob (for example, the Git repository itself) results in output like the
following:
error: missing object referenced by 'refs/tags/junio-gpg-pub'
and if that particular blob is not referenced by a fetched tree, the
resulting clone fails fsck because there is no object from the remote to
vouch that the missing object is a promisor object.
Update both the protocol and the upload-pack implementation to include
all explicitly specified "want" objects in the packfile regardless of
the filter specification.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git send-email documentation specifies RFC 2821 (the SMTP RFC) as
providing line length limits, but the specification that restricts line
length to 998 octets is RFC 2822 (the email message format RFC). Since
RFC 2822 has been obsoleted by RFC 5322, update the text to refer to RFC
5322 instead of RFC 2821.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git send-email, when invoked without a --transfer-encoding option, sends
8bit data without a MIME version or a transfer encoding. This has
several downsides.
First, unless the transfer encoding is specified, it defaults to 7bit,
meaning that non-ASCII data isn't allowed. Second, if lines longer than
998 bytes are used, we will send an message that is invalid according to
RFC 5322. The --validate option, which is the default, catches this
issue, but it isn't clear to many people how to resolve this.
To solve these issues, default the transfer encoding to "auto", so that
we explicitly specify 8bit encoding when lines don't exceed 998 bytes
and quoted-printable otherwise. This means that we now always emit
Content-Transfer-Encoding and MIME-Version headers, so remove the
conditionals from this portion of the code.
It is unlikely that the unconditional inclusion of these two headers
will affect the deliverability of messages in anything but a positive
way, since MIME is already widespread and well understood by most email
programs.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With --validate (which is the default), we warn about lines exceeding
998 characters due to the limits specified in RFC 5322. However, if
we're using a suitable transfer encoding (quoted-printable or base64),
we're guaranteed not to have lines exceeding 76 characters, so there's
no need to fail in this case. The auto transfer encoding handles this
specific case, so accept it as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For most patches, using a transfer encoding of 8bit provides good
compatibility with most servers and makes it as easy as possible to view
patches. However, there are some patches for which 8bit is not a valid
encoding: RFC 5322 specifies that a message must not have lines
exceeding 998 octets.
Add a transfer encoding value, auto, which indicates that a patch should
use 8bit where allowed and quoted-printable otherwise. Choose
quoted-printable instead of base64, since base64-encoded plain text is
treated as suspicious by some spam filters.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
During negotiation, fetch-pack eventually reports as "have" lines all
commits reachable from all refs. Allow the user to restrict the commits
sent in this way by providing a whitelist of tips; only the tips
themselves and their ancestors will be sent.
Both globs and single objects are supported.
This feature is only supported for protocols that support connect or
stateless-connect (such as HTTP with protocol v2).
This will speed up negotiation when the repository has multiple
relatively independent branches (for example, when a repository
interacts with multiple repositories, such as with linux-next [1] and
torvalds/linux [2]), and the user knows which local branch is likely to
have commits in common with the upstream branch they are fetching.
[1] https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next/
[2] https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux/
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current description of "core.ignoreCase" reads like an option which
is intended to be changed by the user while it's actually expected to
be set by Git on initialization only. Subsequently, Git relies on the
proper configuration of this variable, as noted by Bryan Turner [1]:
Git on a case-insensitive filesystem (APFS, HFS+, FAT32, exFAT,
vFAT, NTFS, etc.) is not designed to be run with anything other
than core.ignoreCase=true.
[1] https://marc.info/?l=git&m=152998665813997&w=2
mid:CAGyf7-GeE8jRGPkME9rHKPtHEQ6P1+ebpMMWAtMh01uO3bfy8w@mail.gmail.com
Signed-off-by: Marc Strapetz <marc.strapetz@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit-graph feature shipped in Git 2.18 has some inconsistencies in
the constants used by the implementation and specified by the format
document.
The commit data chunk uses the key "CDAT" in the file format, but was
previously documented to say "CGET".
The commit data chunk stores commit parents using two 32-bit fields that
typically store the integer position of the parent in the list of commit
ids within the commit-graph file. When a parent does not exist, we had
documented the value 0xffffffff, but implemented the value 0x70000000.
This swap is easy to correct in the documentation, but unfortunately
reduces the number of commits that we can store in the commit-graph.
Update that estimate, too.
Reported-by: Grant Welch <gwelch925@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, while performing packfile negotiation, clients are only
allowed to specify their desired objects using object ids. This causes
a vulnerability to failure when an object turns non-existent during
negotiation, which may happen if, for example, the desired repository is
provided by multiple Git servers in a load-balancing arrangement and
there exists replication delay.
In order to eliminate this vulnerability, implement the ref-in-want
feature for the 'fetch' command in protocol version 2. This feature
enables the 'fetch' command to support requests in the form of ref names
through a new "want-ref <ref>" parameter. At the conclusion of
negotiation, the server will send a list of all of the wanted references
(as provided by "want-ref" lines) in addition to the generated packfile.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The default core.excludesfile path is $XDG_CONFIG_HOME/git/ignore.
$HOME/.config/git/ignore is used if XDG_CONFIG_HOME is empty or unset,
as described later in the document.
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
rebase backends currently behave differently with empty commit messages,
largely as a side-effect of the different underlying commands on which
they are based. am-based rebases apply commits with an empty commit
message without stopping or requiring the user to specify an extra flag.
(It is interesting to note that am-based rebases are the default rebase
type, and no one has ever requested a --no-allow-empty-message flag to
change this behavior.) merge-based and interactive-based rebases (which
are ultimately based on git-commit), will currently halt on any such
commits and require the user to manually specify what to do with the
commit and continue.
One possible rationale for the difference in behavior is that the purpose
of an "am" based rebase is solely to transplant an existing history, while
an "interactive" rebase is one whose purpose is to polish a series before
making it publishable. Thus, stopping and asking for confirmation for a
possible problem is more appropriate in the latter case. However, there
are two problems with this rationale:
1) merge-based rebases are also non-interactive and there are multiple
types of rebases that use the interactive machinery but are not
explicitly interactive (e.g. when either --rebase-merges or
--keep-empty are specified without --interactive). These rebases are
also used solely to transplant an existing history, and thus also
should default to --allow-empty-message.
2) this rationale only says that the user is more accepting of stopping
in the case of an explicitly interactive rebase, not that stopping
for this particular reason actually makes sense. Exploring whether
it makes sense, requires backing up and analyzing the underlying
commands...
If git-commit did not error out on empty commits by default, accidental
creation of commits with empty messages would be a very common occurrence
(this check has caught me many times). Further, nearly all such empty
commit messages would be considered an accidental error (as evidenced by a
huge amount of documentation across version control systems and in various
blog posts explaining how important commit messages are). A simple check
for what would otherwise be a common error thus made a lot of sense, and
git-commit gained an --allow-empty-message flag for special case
overrides. This has made commits with empty messages very rare.
There are two sources for commits with empty messages for rebase (and
cherry-pick): (a) commits created in git where the user previously
specified --allow-empty-message to git-commit, and (b) commits imported
into git from other version control systems. In case (a), the user has
already explicitly specified that there is something special about this
commit that makes them not want to specify a commit message; forcing them
to re-specify with every cherry-pick or rebase seems more likely to be
infuriating than helpful. In case (b), the commit is highly unlikely to
have been authored by the person who has imported the history and is doing
the rebase or cherry-pick, and thus the user is unlikely to be the
appropriate person to write a commit message for it. Stopping and
expecting the user to modify the commit before proceeding thus seems
counter-productive.
Further, note that while empty commit messages was a common error case for
git-commit to deal with, it is a rare case for rebase (or cherry-pick).
The fact that it is rare raises the question of why it would be worth
checking and stopping on this particular condition and not others. For
example, why doesn't an interactive rebase automatically stop if the
commit message's first line is 2000 columns long, or is missing a blank
line after the first line, or has every line indented with five spaces, or
any number of other myriad problems?
Finally, note that if a user doing an interactive rebase does have the
necessary knowledge to add a message for any such commit and wants to do
so, it is rather simple for them to change the appropriate line from
'pick' to 'reword'. The fact that the subject is empty in the todo list
that the user edits should even serve as a way to notify them.
As far as I can tell, the fact that merge-based and interactive-based
rebases stop on commits with empty commit messages is solely a by-product
of having been based on git-commit. It went without notice for a long
time precisely because such cases are rare. The rareness of this
situation made it difficult to reason about, so when folks did eventually
notice this behavior, they assumed it was there for a good reason and just
added an --allow-empty-message flag. In my opinion, stopping on such
messages not desirable in any of these cases, even the (explicitly)
interactive case.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a variety of aspects that are common to all rebases regardless
of which backend is in use; however, the behavior for these different
aspects varies in ways that could surprise users. (In fact, it's not
clear -- to me at least -- that these differences were even desirable or
intentional.) Document these differences.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
