The nearby error messages are already marked for
translation, but these new ones aren't.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Like '--continue', the '--abort' option doesn't make any sense with
other options or arguments to 'git merge' so ensure that none are
present.
Signed-off-by: NChris Packham <judge.packham@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Teach 'git merge' the --continue option which allows 'continuing' a
merge by completing it. The traditional way of completing a merge after
resolving conflicts is to use 'git commit'. Now with commands like 'git
rebase' and 'git cherry-pick' having a '--continue' option adding such
an option to 'git merge' presents a consistent UI.
Signed-off-by: NChris Packham <judge.packham@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Callers of the hold_locked_index() function pass 0 when they want to
prepare to write a new version of the index file without wishing to
die or emit an error message when the request fails (e.g. somebody
else already held the lock), and pass 1 when they want the call to
die upon failure.

This option is called LOCK_DIE_ON_ERROR by the underlying lockfile
API, and the hold_locked_index() function translates the paramter to
LOCK_DIE_ON_ERROR when calling the hold_lock_file_for_update().

Replace these hardcoded '1' with LOCK_DIE_ON_ERROR and stop
translating.  Callers other than the ones that are replaced with
this change pass '0' to the function; no behaviour change is
intended with this patch.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
---

Among the callers of hold_locked_index() that passes 0:

 - diff.c::refresh_index_quietly() at the end of "git diff" is an
   opportunistic update; it leaks the lockfile structure but it is
   just before the program exits and nobody should care.

 - builtin/describe.c::cmd_describe(),
   builtin/commit.c::cmd_status(),
   sequencer.c::read_and_refresh_cache() are all opportunistic
   updates and they are OK.

 - builtin/update-index.c::cmd_update_index() takes a lock upfront
   but we may end up not needing to update the index (i.e. the
   entries may be fully up-to-date), in which case we do not need to
   issue an error upon failure to acquire the lock.  We do diagnose
   and die if we indeed need to update, so it is OK.

 - wt-status.c::require_clean_work_tree() IS BUGGY.  It asks
   silence, does not check the returned value.  Compare with
   callsites like cmd_describe() and cmd_status() to notice that it
   is wrong to call update_index_if_able() unconditionally.

Some code paths want to format multiple abbreviated sha1s in
the same output line. Because we use a single static buffer
for our return value, they have to either break their output
into several calls or allocate their own arrays and use
find_unique_abbrev_r().

Intead, let's mimic sha1_to_hex() and use a ring of several
buffers, so that the return value stays valid through
multiple calls. This shortens some of the callers, and makes
it harder to for them to make a silly mistake.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Replace uses of strbuf_addf() for adding strings with more lightweight
strbuf_addstr() calls.  This makes the intent clearer and avoids
potential issues with printf format specifiers.

02962d36 already converted six cases,
this patch covers eleven more.

A semantic patch for Coccinelle is included for easier checking for
new cases that might be introduced in the future.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Call string_list_split() for cutting a space separated list into pieces
instead of reimplementing it based on struct strategy.  The attr member
of struct strategy was not used split_merge_strategies(); it was a pure
string operation.  Also be nice and clean up once we're done splitting;
the old code didn't bother freeing any of the allocated memory.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Previously, callers of merge_trees() or merge_recursive() expected that
code to die() with an error message. This used to be okay because we
called those commands from scripts, and had a chance to print out a
message in case the command failed fatally (read: with exit code 128).

As scripting incurs its own set of problems (portability, speed,
idiosyncrasies of different shells, limited data structures leading to
inefficient code), we are converting more and more of these scripts into
builtins, using library functions directly.

We already tried to use merge_recursive() directly in the builtin
git-am, for example. Unfortunately, we had to roll it back temporarily
because some of the code in merge-recursive.c still deemed it okay to
call die(), when the builtin am code really wanted to print out a useful
advice after the merge failed fatally. In the next commits, we want to
fix that.

The code touched by this commit expected merge_trees() to die() with
some useful message when there is an error condition, but merge_trees()
is going to be improved by converting all die() calls to return error()
instead (i.e. return value -1 after printing out the message as before),
so that the caller can react more flexibly.

This is a step to prepare for the version of merge_trees() that no
longer dies,  even if we just imitate the previous behavior by calling
exit(128): this is what callers of e.g. `git merge` have come to expect.

Note that the callers of the sequencer (revert and cherry-pick) already
fail fast even for the return value -1; The only difference is that they
now get a chance to say "<command> failed".

A caller of merge_trees() might want handle error messages themselves
(or even suppress them). As this patch is already complex enough, we
leave that change for a later patch.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There are several places where we open a file, write some
content from a strbuf, and close it. These can be simplified
with write_file_buf(). As a bonus, many of these did not
catch write problems at close() time.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Apply the set of semantic patches from contrib/coccinelle to convert
some leftover places using struct object_id's hash member to instead
use the wrapper functions that take struct object_id natively.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

hashcpy with null_sha1 as the source is equivalent to hashclr.  In
addition to being simpler, using hashclr may give the compiler a chance
to optimize better.  Convert instances of hashcpy with the source
argument of null_sha1 to hashclr.

This transformation was implemented using the following semantic patch:

@@
expression E1;
@@
-hashcpy(E1, null_sha1);
+hashclr(E1);
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change command option description to lowercase, matching pull
counterpart option. Translators would have to translate such message
only once.
Signed-off-by: NVasco Almeida <vascomalmeida@sapo.pt>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Mark messages shown to the user for translation.
Signed-off-by: NVasco Almeida <vascomalmeida@sapo.pt>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If read_tree_trivial() succeeds and produces a tree that is already
in the object store, then the index is not written to disk, leaving
it out-of-sync with both HEAD and the working tree.

In order to write the index back out to disk after a merge,
write_index_locked() needs to be called.  For most merge strategies, this
is done from try_merge_strategy().  For fast forward updates, this is
done from checkout_fast_forward().  When trivial merges work, the call to
write_index_locked() is buried a little deeper:

  merge_trivial()
  -> write_tree_trivial()
     -> write_cache_as_tree()
        -> write_index_as_tree()
           -> write_locked_index()

However, it is only called when !cache_tree_fully_valid(), which is how
this bug is triggered.  But that also shows why this bug doesn't affect
any other merge strategies or cases.

Add a direct call to write_index_locked() from merge_trivial() to fix
this issue.  Since the indirect call to write_locked_index() was
conditional on cache_tree_fully_valid(), it won't be written twice.
Signed-off-by: NElijah Newren <newren@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It is never read, so we can pass NULL to resolve_ref_unsafe().
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NDavid Turner <dturner@twopensource.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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: NJunio 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: NJunio 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: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio 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: NJeff King <peff@peff.net>
Signed-off-by: NJunio 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: NJohannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio 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: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff 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: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff 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: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff King <peff@peff.net>

Instead of open-coding the function pop_commit() just call it.  This
makes the intent clearer and reduces code size.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio 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: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NJunio 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: NJeff King <peff@peff.net>
Signed-off-by: NJunio 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: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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: NJunio 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: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio 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: NJunio 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: NJunio 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: NJunio 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: NJunio 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: NJunio 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: NJunio 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: NJunio C Hamano <gitster@pobox.com>