"git merge" used to allow merging two branches that have no common
base by default, which led to a brand new history of an existing
project created and then get pulled by an unsuspecting maintainer,
which allowed an unnecessary parallel history merged into the
existing project. The command has been taught not to allow this by
default, with an escape hatch "--allow-unrelated-histories" option
to be used in a rare event that merges histories of two projects
that started their lives independently.
* jc/merge-refuse-new-root:
merge: refuse to create too cool a merge by default
"git merge FETCH_HEAD" dereferenced NULL pointer when merging
nothing into an unborn history (which is arguably unusual usage,
which perhaps was the reason why nobody noticed it).
* jv/merge-nothing-into-void:
merge: fix NULL pointer dereference when merging nothing into void
The end-user facing Porcelain level commands like "diff" and "log"
now enables the rename detection by default.
* mm/diff-renames-default:
diff: activate diff.renames by default
log: introduce init_log_defaults()
t: add tests for diff.renames (true/false/unset)
t4001-diff-rename: wrap file creations in a test
Documentation/diff-config: fix description of diff.renames
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>
When we are on an unborn branch and merging only one foreign parent,
we allow "git merge" to fast-forward to that foreign parent commit.
This codepath incorrectly attempted to dereference the list of
parents that the merge is going to record even when the list is
empty. It must refuse to operate instead when there is no parent.
All other codepaths make sure the list is not empty before they
dereference it, and are safe.
Reported-by: Jose Ivan B. Vilarouca Filho
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename detection is a very convenient feature, and new users shouldn't
have to dig in the documentation to benefit from it.
Potential objections to activating rename detection are that it
sometimes fail, and it is sometimes slow. But rename detection is
already activated by default in several cases like "git status" and "git
merge", so activating diff.renames does not fundamentally change the
situation. When the rename detection fails, it now fails consistently
between "git diff" and "git status".
This setting does not affect plumbing commands, hence well-written
scripts will not be affected.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If our size computation overflows size_t, we may allocate a
much smaller buffer than we expected and overflow it. It's
probably impossible to trigger an overflow in most of these
sites in practice, but it is easy enough convert their
additions and multiplications into overflow-checking
variants. This may be fixing real bugs, and it makes
auditing the code easier.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before auto-gc'ing, we need to make sure that the pack files are
released in case they need to be repacked and garbage-collected.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert all instances of get_object_hash to use an appropriate reference
to the hash member of the oid member of struct object. This provides no
functional change, as it is essentially a macro substitution.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
struct object is one of the major data structures dealing with object
IDs. Convert it to use struct object_id instead of an unsigned char
array. Convert get_object_hash to refer to the new member as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Convert most instances where the sha1 member of struct object is
dereferenced to use get_object_hash. Most instances that are passed to
functions that have versions taking struct object_id, such as
get_sha1_hex/get_oid_hex, or instances that can be trivially converted
to use struct object_id instead, are not converted.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
The internal stripspace() function has been moved to where it
logically belongs to, i.e. strbuf API, and the command line parser
of "git stripspace" has been updated to use the parse_options API.
* tk/stripspace:
stripspace: use parse-options for command-line parsing
strbuf: make stripspace() part of strbuf
Instead of open-coding the function pop_commit() just call it. This
makes the intent clearer and reduces code size.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function is also used in other builtins than stripspace, so it
makes sense to have it in a more generic place. Since it operates
on an strbuf and the function is declared in strbuf.h, move it to
strbuf.c and add the corresponding prefix to its name, just like
other API functions in the strbuf_* family.
Also switch all current users of stripspace() to the new function
name and keep a temporary wrapper inline function for any topic
branches still using stripspace().
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before sha1_to_hex_r() existed, a simple way to get hex
sha1 into a buffer was with:
strcpy(buf, sha1_to_hex(sha1));
This isn't wrong (assuming the buf is 41 characters), but it
makes auditing the code base for bad strcpy() calls harder,
as these become false positives.
Let's convert them to sha1_to_hex_r(), and likewise for
some calls to find_unique_abbrev(). While we're here, we'll
double-check that all of the buffers are correctly sized,
and use the more obvious GIT_SHA1_HEXSZ constant.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of the most common uses of git_path() is to pass a
constant, like git_path("MERGE_MSG"). This has two
drawbacks:
1. The return value is a static buffer, and the lifetime
is dependent on other calls to git_path, etc.
2. There's no compile-time checking of the pathname. This
is OK for a one-off (after all, we have to spell it
correctly at least once), but many of these constant
strings appear throughout the code.
This patch introduces a series of functions to "memoize"
these strings, which are essentially globals for the
lifetime of the program. We compute the value once, take
ownership of the buffer, and return the cached value for
subsequent calls. cache.h provides a helper macro for
defining these functions as one-liners, and defines a few
common ones for global use.
Using a macro is a little bit gross, but it does nicely
document the purpose of the functions. If we need to touch
them all later (e.g., because we learned how to change the
git_dir variable at runtime, and need to invalidate all of
the stored values), it will be much easier to have the
complete list.
Note that the shared-global functions have separate, manual
declarations. We could do something clever with the macros
(e.g., expand it to a declaration in some places, and a
declaration _and_ a definition in path.c). But there aren't
that many, and it's probably better to stay away from
too-magical macros.
Likewise, if we abandon the C preprocessor in favor of
generating these with a script, we could get much fancier.
E.g., normalizing "FOO/BAR-BAZ" into "git_path_foo_bar_baz".
But the small amount of saved typing is probably not worth
the resulting confusion to readers who want to grep for the
function's definition.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce <branch>@{push} short-hand to denote the remote-tracking
branch that tracks the branch at the remote the <branch> would be
pushed to.
* jk/at-push-sha1:
for-each-ref: accept "%(push)" format
for-each-ref: use skip_prefix instead of starts_with
sha1_name: implement @{push} shorthand
sha1_name: refactor interpret_upstream_mark
sha1_name: refactor upstream_mark
remote.c: add branch_get_push
remote.c: return upstream name from stat_tracking_info
remote.c: untangle error logic in branch_get_upstream
remote.c: report specific errors from branch_get_upstream
remote.c: introduce branch_get_upstream helper
remote.c: hoist read_config into remote_get_1
remote.c: provide per-branch pushremote name
remote.c: hoist branch.*.remote lookup out of remote_get_1
remote.c: drop "remote" pointer from "struct branch"
remote.c: refactor setup of branch->merge list
remote.c: drop default_remote_name variable
When we create each branch struct, we fill in the
"remote_name" field from the config, and then fill in the
actual "remote" field (with a "struct remote") based on that
name. However, it turns out that nobody really cares about
the latter field. The only two sites that access it at all
are:
1. git-merge, which uses it to notice when the branch does
not have a remote defined. But we can easily replace this
with looking at remote_name instead.
2. remote.c itself, when setting up the @{upstream} merge
config. But we don't need to save the "remote" in the
"struct branch" for that; we can just look it up for
the duration of the operation.
So there is no need to have both fields; they are redundant
with each other (the struct remote contains the name, or you
can look up the struct from the name). It would be nice to
simplify this, especially as we are going to add matching
pushremote config in a future patch (and it would be nice to
keep them consistent).
So which one do we keep and which one do we get rid of?
If we had a lot of callers accessing the struct, it would be
more efficient to keep it (since you have to do a lookup to
go from the name to the struct, but not vice versa). But we
don't have a lot of callers; we have exactly one, so
efficiency doesn't matter. We can decide this based on
simplicity and readability.
And the meaning of the struct value is somewhat unclear. Is
it always the remote matching remote_name? If remote_name is
NULL (i.e., no per-branch config), does the struct fall back
to the "origin" remote, or is it also NULL? These questions
will get even more tricky with pushremotes, whose fallback
behavior is more complicated. So let's just store the name,
which pretty clearly represents the branch.*.remote config.
Any lookup or fallback behavior can then be implemented in
helper functions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git merge FETCH_HEAD" learned that the previous "git fetch" could
be to create an Octopus merge, i.e. recording multiple branches
that are not marked as "not-for-merge"; this allows us to lose an
old style invocation "git merge <msg> HEAD $commits..." in the
implementation of "git pull" script; the old style syntax can now
be deprecated.
* jc/merge:
merge: deprecate 'git merge <message> HEAD <commit>' syntax
merge: handle FETCH_HEAD internally
merge: decide if we auto-generate the message early in collect_parents()
merge: make collect_parents() auto-generate the merge message
merge: extract prepare_merge_message() logic out
merge: narrow scope of merge_names
merge: split reduce_parents() out of collect_parents()
merge: clarify collect_parents() logic
merge: small leakfix and code simplification
merge: do not check argc to determine number of remote heads
merge: clarify "pulling into void" special case
t5520: test pulling an octopus into an unborn branch
t5520: style fixes
merge: simplify code flow
merge: test the top-level merge driver
We had this in "git merge" manual for eternity:
'git merge' <msg> HEAD <commit>...
[This] syntax (<msg> `HEAD` <commit>...) is supported for
historical reasons. Do not use it from the command line or in
new scripts. It is the same as `git merge -m <msg> <commit>...`.
With the update to "git merge" to make it understand what is
recorded in FETCH_HEAD directly, including Octopus merge cases, we
now can rewrite the use of this syntax in "git pull" with a simple
"git merge FETCH_HEAD".
Also there are quite a few fallouts in the test scripts, and it
turns out that "git cvsimport" also uses this old syntax to record
a merge.
Judging from this result, I would not be surprised if dropping the
support of the old syntax broke scripts people have written and been
relying on for the past ten years. But at least we can start the
deprecation process by throwing a warning message when the syntax is
used.
With luck, we might be able to drop the support in a few years.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The collect_parents() function now is responsible for
1. parsing the commits given on the command line into a list of
commits to be merged;
2. filtering these parents into independent ones; and
3. optionally calling fmt_merge_msg() via prepare_merge_message()
to prepare an auto-generated merge log message, using fake
contents that FETCH_HEAD would have had if these commits were
fetched from the current repository with "git pull . $args..."
Make "git merge FETCH_HEAD" to be the same as the traditional
git merge "$(git fmt-merge-msg <.git/FETCH_HEAD)" $commits
invocation of the command in "git pull", where $commits are the ones
that appear in FETCH_HEAD that are not marked as not-for-merge, by
making it do a bit more, specifically:
- noticing "FETCH_HEAD" is the only "commit" on the command line
and picking the commits that are not marked as not-for-merge as
the list of commits to be merged (substitute for step #1 above);
- letting the resulting list fed to step #2 above;
- doing the step #3 above, using the contents of the FETCH_HEAD
instead of fake contents crafted from the list of commits parsed
in the step #1 above.
Note that this changes the semantics. "git merge FETCH_HEAD" has
always behaved as if the first commit in the FETCH_HEAD file were
directly specified on the command line, creating a two-way merge
whose auto-generated merge log said "merge commit xyz". With this
change, if the previous fetch was to grab multiple branches (e.g.
"git fetch $there topic-a topic-b"), the new world order is to
create an octopus, behaving as if "git pull $there topic-a topic-b"
were run. This is a deliberate change to make that happen, and
can be seen in the changes to t3033 tests.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to pass the list of parents to fmt_merge_msg(), cmd_merge()
uses this strbuf to create something that look like FETCH_HEAD that
describes commits that are being merged. This is necessary only
when we are creating the merge commit message ourselves, but was
done unconditionally.
Move the variable and the logic to populate it to confine them in a
block that needs them.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The latter does two separate things:
- Parse the list of commits on the command line, and formulate the
list of commits to be merged (including the current HEAD);
- Compute the list of parents to be recorded in the resulting merge
commit.
Split the latter into a separate helper function, so that we can
later supply the list commits to be merged from a different source
(namely, FETCH_HEAD).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Clarify this small function in three ways.
- The function initially collects all commits to be merged into a
commit_list "remoteheads"; the "remotes" pointer always points at
the tail of this list (either the remoteheads variable itself, or
the ->next slot of the element at the end of the list) to help
elongate the list by repeated calls to commit_list_insert().
Because the new element appended by commit_list_insert() will
always have its ->next slot NULLed out, there is no need for us
to assign NULL to *remotes to terminate the list at the end.
- The variable "head_subsumed" always confused me every time I read
this code. What is happening here is that we inspect what the
caller told us to merge (including the current HEAD) and come up
with the list of parents to be recorded for the resulting merge
commit, omitting commits that are ancestor of other commits.
This filtering may remove the current HEAD from the resulting
parent list---and we signal that fact with this variable, so that
we can later record it as the first parent when "--no-ff" is in
effect.
- The "parents" list is created for this function by reduce_heads()
and was not deallocated after its use, even though the loop
control was written in such a way to allow us to do so by taking
the "next" element in a separate variable so that it can be used
in the next-step part of the loop control.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When parsing a merged object name like "foo~20" to formulate a merge
summary "Merge branch foo (early part)", a temporary strbuf is used,
but we forgot to deallocate it when we failed to find the named
branch.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To reject merging multiple commits into an unborn branch, we check
argc, thinking that collect_parents() that reads the remaining
command line arguments from <argc, argv> will give us the same
number of commits as its input, i.e. argc.
Because what we really care about is the number of commits, let the
function run and then make sure it returns only one commit instead.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of having it as one of the three if/elseif/.. case arms,
test the condition and handle this special case upfront. This makes
it easier to follow the flow of logic.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of the first things cmd_merge() does is to see if the "--abort"
option is given and run "reset --merge" and exit. When the control
reaches this point, we know "--abort" was not given.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit 2bf15a3330, whose
intention was good, but the verbosity levels used in merge-recursive
turns out to be rather uneven. For example, a merge of two branches
with conflicting submodule updates used to report CONFLICT: output
with --quiet but no longer (which *is* desired), while the final
"Automatic merge failed; fix conflicts and then commit" message is
still shown even with --quiet (which *is* inconsistent).
Originally reported by Bryan Turner; it is too early to declare what
the concensus is, but it seems that we would need to level the
verbosity levels used in merge strategy backends before we can go
forward. In the meantime, we'd revert to the old behaviour until
that happens.
cf. $gmane/267245
"git merge --quiet" did not squelch messages from the underlying
merge-recursive strategy.
* jk/merge-quiet:
merge: pass verbosity flag down to merge-recursive
This makes "git merge --quiet" really quiet when we call
into merge-recursive.
Note that we can't just pass our flag down as-is; the two
parts of the code use different scales. We center at "0" as
normal for git-merge (with "--quiet" giving a negative
value), but merge-recursive uses "2" as its center. This
patch passes a negative value to merge-recursive rather than
"1", though, as otherwise the user would have to use "-qqq"
to squelch all messages (but the downside is that the user
cannot distinguish between levels 0-2 if without resorting
to the GIT_MERGE_VERBOSITY variable).
We may want to review and renormalize the message severities
in merge-recursive, but that does not have to happen now.
This is at least in improvement in the sense that we are
respecting "--quiet" at all.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch puts the usage info strings that were not already in docopt-
like format into docopt-like format, which will be a litle easier for
end users and a lot easier for translators. Changes include:
- Placing angle brackets around fill-in-the-blank parameters
- Putting dashes in multiword parameter names
- Adding spaces to [-f|--foobar] to make [-f | --foobar]
- Replacing <foobar>* with [<foobar>...]
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_merge_bases*() API was easy to misuse by careless
copy&paste coders, leaving object flags tainted in the commits that
needed to be traversed.
* jc/merge-bases:
get_merge_bases(): always clean-up object flags
bisect: clean flags after checking merge bases
"git interpret-trailers" learned to properly handle the
"Conflicts:" block at the end.
* cc/interpret-trailers-more:
trailer: add test with an old style conflict block
trailer: reuse ignore_non_trailer() to ignore conflict lines
commit: make ignore_non_trailer() non static
merge & sequencer: turn "Conflicts:" hint into a comment
builtin/commit.c: extract ignore_non_trailer() helper function
merge & sequencer: unify codepaths that write "Conflicts:" hint
builtin/merge.c: drop a parameter that is never used
* jc/conflict-hint:
merge & sequencer: turn "Conflicts:" hint into a comment
builtin/commit.c: extract ignore_non_trailer() helper function
merge & sequencer: unify codepaths that write "Conflicts:" hint
builtin/merge.c: drop a parameter that is never used
git-tag.txt: Add a missing hyphen to `-s`
The callers of get_merge_bases() can choose to leave object flags
used during the merge-base traversal by passing cleanup=0 as a
parameter, but in practice a very few callers can afford to do so
(namely, "git merge-base"), as they need to compute merge base in
preparation for other processing of their own and they need to see
the object without contaminate flags.
Change the function signature of get_merge_bases_many() and
get_merge_bases() to drop the cleanup parameter, so that the
majority of the callers do not have to say ", 1" at the end.
Give a new get_merge_bases_many_dirty() API to support only a few
callers that know they do not need to spend cycles cleaning up the
object flags.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Two identical loops in suggest_conflicts() in merge, and
do_recursive_merge() in sequencer, can use a single helper function
extracted from the latter that prepares the "Conflicts:" hint that
is meant to remind the user the paths for which merge conflicts had
to be resolved to write a better commit log message.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the very beginning when we added the "renormalizing" parameter
to this function with 7610fa57 (merge-recursive --renormalize,
2010-08-05), nobody seems to have ever referenced it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
resolve_ref_unsafe takes a boolean argument for reading (a nonexistent ref
resolves successfully for writing but not for reading). Change this to be
a flags field instead, and pass the new constant RESOLVE_REF_READING when
we want this behaviour.
While at it, swap two of the arguments in the function to put output
arguments at the end. As a nice side effect, this ensures that we can
catch callers that were unaware of the new API so they can be audited.
Give the wrapper functions resolve_refdup and read_ref_full the same
treatment for consistency.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the interface declaration for the functions in lockfile.c from
cache.h to a new file, lockfile.h. Add #includes where necessary (and
remove some redundant includes of cache.h by files that already
include builtin.h).
Move the documentation of the lock_file state diagram from lockfile.c
to the new header file.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Even the one lockfile object needn't be allocated each time the
function is called. Instead, define one statically-allocated
lock_file object and reuse it for every call.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By the time the "if" block is entered, the lock_file instance from the
main function block is no longer in use, so re-use that one instead of
allocating a second one.
Note that the "lock" variable in the "if" block shadowed the "lock"
variable at function scope, so the only change needed is to remove the
inner definition.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
