Also leave a warning for future merge-recursive explorers.
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If a file is changed in one branch, and renamed and changed to the
same content in another branch than we can skip the rewrite of this
file in the working directory, as the content does not change.
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The mess known as the progress meter in merge-recursive was my own
fault; I put it in thinking that we might be spending a lot of time
resolving unmerged entries in the index that were not handled by
the simple 3-way index merge code.
Turns out we don't really spend that much time there, so the progress
meter was pretty much always jumping to "(n/n) 100%" as soon as
the program started. That isn't a very good indication of progress.
Since I don't have a great solution for how a progress meter should
work here, I'm proposing we back it out entirely.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Alex Riesen noticed that the case where a file replaced a directory entry
in the working tree was broken on cygwin. It turns out that the code made
some Linux-specific assumptions, and also ignored errors entirely for the
case where the entry was a symlink rather than a file.
This cleans it up by separating out the common case into a function of its
own, so that both regular files and symlinks can share it, and by making
the error handling more obvious (and not depend on any Linux-specific
behaviour).
Acked-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
There is no need to intern the string to git_attr, as we are already
dealing with the name of the driver there.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When the configuration has variables unrelated to low-level
merge drivers (e.g. merge.summary), the code failed to ignore
them but did something totally senseless.
Signed-off-by: Junio C Hamano <junkio@cox.net>
It was bothering me a lot that I abused small integer values
casted to (void *) to represent non string values in
gitattributes. This corrects it by making the type of attribute
values (const char *), and using the address of a few statically
allocated character buffer to denote true/false. Unset attributes
are represented as having NULLs as their values.
Added in-header documentation to explain how git_checkattr()
routine should be called.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows [merge "drivername"] to have a variable "recursive"
that names a different low-level merge driver to be used when
merging common ancestors to come up with a virtual ancestor.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This changes the configuration syntax for defining a low-level
merge driver to be:
[merge "<<drivername>>"]
driver = "<<command line>>"
name = "<<driver description>>"
which is much nicer to read and is extensible. Credit goes to
Martin Waitz and Linus.
In addition, when we use an external low-level merge driver, it
is reported as an extra output from merge-recursive, using the
value of merge.<<drivername>.name variable.
The demonstration in t6026 has also been updated.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When no 'merge' attribute is given to a path, merge-recursive
uses the built-in xdl-merge as the low-level merge driver.
A new configuration item 'merge.default' can name a low-level
merge driver of user's choice to be used instead.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows users to specify custom low-level merge driver per
path, using the attributes mechanism. Just like you can specify
one of built-in "text", "binary", "union" low-level merge
drivers by saying:
* merge=text
.gitignore merge=union
*.jpg merge=binary
pick a name of your favorite merge driver, and assign it as the
value of the 'merge' attribute.
A custom low-level merge driver is defined via the config
mechanism. This patch introduces 'merge.driver', a multi-valued
configuration. Its value is the name (i.e. the one you use as
the value of 'merge' attribute) followed by a command line
specification. The command line can contain %O, %A, and %B to
be interpolated with the names of temporary files that hold the
common ancestor version, the version from your branch, and the
version from the other branch, and the resulting command is
spawned.
The low-level merge driver is expected to update the temporary
file for your branch (i.e. %A) with the result and exit with
status 0 for a clean merge, and non-zero status for a conflicted
merge.
A new test in t6026 demonstrates a sample usage.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows 'merge' attribute to control how the file-level
three-way merge is done per path.
- If you set 'merge' to true, leave it unspecified, or set it
to "text", we use the built-in 3-way xdl-merge.
- If you set 'merge' to false, or set it to "binary, the
"binary" merge is done. The merge result is the blob from
'our' tree, but this still leaves the path conflicted, so
that the mess can be sorted out by the user. This is
obviously meant to be useful for binary files.
- 'merge=union' (this is the first example of a string valued
attribute, introduced in the previous one) uses the "union"
merge. The "union" merge takes lines in conflicted hunks
from both sides, which is useful for line-oriented files such
as .gitignore.
Instead fo setting merge to 'true' or 'false' by using 'merge'
or '-merge', setting it explicitly to "text" or "binary" will
become useful once we start allowing custom per-path backends to
be added, and allow them to be activated for the default
(i.e. 'merge' attribute specified to 'true' or 'false') case,
using some other mechanisms. Setting merge attribute to "text"
or "binary" will be a way to explicitly request to override such
a custom default for selected paths.
Currently there is no way to specify random programs but it
should be trivial for motivated contributors to add later.
There is one caveat, though. ll_merge() is called for both
internal ancestor merge and the outer "final" merge. I think an
interactive custom per-path merge backend should refrain from
going interactive when performing an internal merge (you can
tell it by checking call_depth) and instead just call either
ll_xdl_merge() if the content is text, or call ll_binary_merge()
otherwise.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When a path D that originally was blob in the ancestor was
modified on our branch while it was removed on the other branch,
we keep stages 1 and 2, and leave our version in the working
tree. If the other branch created a path D/F, however, that
path can cleanly be resolved in the index (after all, the
ancestor nor we do not have it and only the other side added),
but it cannot be checked out. The issue is the same when the
other branch had D and we had renamed it to D/F, or the ancestor
had D/F instead of D (so there are four combinations).
Do not stop the merge, but leave both D and D/F paths in the
index so that the user can clear things up.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When update-trees::threeway_merge() decides that a path that
exists in the current index (and HEAD) is to be removed, it
leaves a stage 0 entry whose mode bits are set to 0. The code
mistook it as "this stage wants the blob here", and proceeded
to call update_file_flags() which ended up trying to put the
mode=0 entry in the index, got very confused, and ended up
barfing with "do not know what to do with 000000".
Since threeway_merge() does not handle case #10 (one side
removes while the other side does not do anything), this is not
a problem while we refuse to merge branches that have D/F
conflicts, but when we start resolving them, we would need to be
able to remove cache entries, and at that point it starts to
matter.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This merge strategy largely piggy-backs on git-merge-recursive.
When merging trees A and B, if B corresponds to a subtree of A,
B is first adjusted to match the tree structure of A, instead of
reading the trees at the same level. This adjustment is also
done to the common ancestor tree.
If you are pulling updates from git-gui repository into git.git
repository, the root level of the former corresponds to git-gui/
subdirectory of the latter. The tree object of git-gui's toplevel
is wrapped in a fake tree object, whose sole entry has name 'git-gui'
and records object name of the true tree, before being used by
the 3-way merge code.
If you are merging the other way, only the git-gui/ subtree of
git.git is extracted and merged into git-gui's toplevel.
The detection of corresponding subtree is done by comparing the
pathnames and types in the toplevel of the tree.
Heuristics galore! That's the git way ;-).
Signed-off-by: Junio C Hamano <junkio@cox.net>
This error message should not usually trigger, but the function
make_cache_entry() called by add_cacheinfo() can return early
without calling into refresh_cache_entry() that sets cache_errno.
Also the error message had a wrong function name reported, and
it did not say anything about which path failed either.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When defined, this allows plumbing commands that update the
index (add, apply, checkout-index, merge-recursive, mv,
read-tree, rm, update-index, and write-tree) to write their
resulting index to an alternative index file while holding a
lock to the original index file. With this, git-commit that
jumps the index does not have to make an extra copy of the index
file, and more importantly, it can do the update while holding
the lock on the index.
However, I think the interface to let an environment variable
specify the output is a mistake, as shown in the documentation.
If a curious user has the environment variable set to something
other than the file GIT_INDEX_FILE points at, almost everything
will break. This should instead be a command line parameter to
tell these plumbing commands to write the result in the named
file, to prevent stupid mistakes.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch leaves the base name in the resulting intermediate tree, to
propagate the conflict from intermediate merges up to the top-level merge.
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If the file system does not support symbolic links (core.symlinks=false),
merge-recursive must write the merged symbolic link text into a regular
file.
While we are here, fix a tiny memory leak in the if-branch that writes
real symbolic links.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We currently have two parallel notation for dealing with object types
in the code: a string and a numerical value. One of them is obviously
redundent, and the most used one requires more stack space and a bunch
of strcmp() all over the place.
This is an initial step for the removal of the version using a char array
found in object reading code paths. The patch is unfortunately large but
there is no sane way to split it in smaller parts without breaking the
system.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Commit 3af244ca added unlink(2) before running symlink(2) to
update the working tree with the merge result, but it was
unlinking a wrong path. This resulted in loss of the path
pointed by a symlink.
Signed-off-by: Junio C Hamano <junkio@cox.net>
git-merge-recursive wants an null tree as the fake merge base
while producing the merge result tree. The null tree does not
have to be written out in the object store as it won't be part
of the result, and it is a prime example for using the new
pretend_sha1_file() function.
git-blame needs to register an arbitrary data to in-core index
while annotating a working tree file (or standard input), but
git-blame is a read-only application and the user of it could
even lack the privilege to write into the object store; it is
another good example for pretend_sha1_file().
Signed-off-by: Junio C Hamano <junkio@cox.net>
My earlier fix (8371234e) to delete renamed tracked files from the
working directory also caused merge-recursive to delete untracked
files that were in the working directory.
The problem here is merge-recursive is deleting the working directory
file without regard for which branch it was associated with. What we
really want to do during a merge is to only delete files that were
renamed by the branch we are merging into the current branch,
and that are still tracked by the current branch. These files
definitely don't belong in the working directory anymore.
Anything else is either a merge conflict (already handled in other
parts of the code) or a file that is untracked by the current branch
and thus is not even participating in the merge. Its this latter
class that must be left alone.
For this fix to work we are now assuming that the first non-base
argument passed to git-merge-recursive always corresponds to the
working directory. This is already true for all in-tree callers
of merge-recursive. This assumption is also supported by the
long time usage message of "<base> ... -- <head> <remote>", where
"<head>" is implied to be HEAD, which is generally assumed to be
the current tree-ish.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Now that we are showing the output messages for verbosity levels
<5 after all actions have been performed (due to the progress meter
running during the actions) it can be confusing to see messages in
the present tense when the user is looking at a '100% done' message
right above them. Converting the messages to past tense will appear
more correct in this case, and shouldn't affect a developer who is
debugging the application and running it at a verbosity level >=5.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Because large merges on slow systems can take up to a minute to
execute we should try to keep the user entertained with a progress
meter to let them know how far we have progressed through the
current merge.
The progress meter considers each entry in the in-memory index to
be a unit, which means a single recursive merge will double the
number of units in the progress meter. Files which are unmerged
after the 3-way tree merge are also considered a unit within the
progress meter.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Buffering all message output until a merge invocation is complete is
necessary to prevent intereferring with a progress meter that would
indicate the number of files completely merged, and how many remain.
This change does not introduce a progress meter, but merely lays
the groundwork to buffer the output.
To aid debugging output buffering is only enabled if verbosity
is lower than 5. When using verbosity levels above 5 the user is
probably debugging the merge program itself and does not want to
see the output delayed, especially if they are stepping through
portions of the code in a debugger.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Junio C Hamano <junkio@cox.net> writes:
>
> I think the output from merge-recursive can be categorized into 5
> verbosity levels:
>
> 1. "CONFLICT", "Rename", "Adding here instead due to D/F conflict"
> (outermost)
>
> 2. "Auto-merged successfully" (outermost)
>
> 3. The first "Merging X with Y".
>
> 4. outermost "Merging:\ntitle1\ntitle2".
>
> 5. outermost "found N common ancestors\nancestor1\nancestor2\n..."
> and anything from inner merge.
>
> I would prefer the default verbosity level to be 2 (that is, show
> both 1 and 2).
and this change makes it so. I think level 3 is probably pointless
as its only one line of output above level 2, but I can see how some
users may want to view it but not view the slightly more verbose
output of level 4.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Because the output_indent always matches the call_depth value
there is no reason to pass around the call_depth to the merge
function during each recursive invocation.
This is a simple refactoring that will make the code easier to
follow later on as I start to add output verbosity controls.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
It is not available in the outermost merge, and it is only
useful for debugging merge-recursive in the inner merges.
Sergey Vlasov noticed that the old code accesses an
uninitialized location.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This revamps the merge-recursive implementation following the
outline in:
Message-ID: <7v8xgileza.fsf@assigned-by-dhcp.cox.net>
There is no need to write out the index until the very end just
once from merge-recursive. Also there is no need to write out
the resulting tree object for the simple case of merging with a
single merge base.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The merge-recursive implementation in C inherited the invariant
that the on-file index file is written out and later read back
after any index operations and writing trees from the original
Python implementation. But it was only because the original
implementation worked at the scripting level.
There is no need to write out the index file after handling
every path.
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We have a number of badly checked write() calls. Often we are
expecting write() to write exactly the size we requested or fail,
this fails to handle interrupts or short writes. Switch to using
the new write_in_full(). Otherwise we at a minimum need to check
for EINTR and EAGAIN, where this is appropriate use xwrite().
Note, the changes to config handling are much larger and handled
in the next patch in the sequence.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
To support wider use cases, such as from within `git am -3`, the
merge-recursive utility needs to accept not just commit-ish but
also tree-ish as arguments on its command line.
If given a tree-ish then merge-recursive will create a virtual commit
wrapping it, with the subject of the commit set to the best name we
can derive for that tree, which is either the command line string
(probably the SHA1), or whatever string appears in GITHEAD_*.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
To permit the get_ref function to use the static better_branch_name
function to generate a string on demand I'm moving it up earlier.
The actual logic was not affected in this change.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Displaying the SHA1 of 'their' branch (the branch being merged into
the current branch) is not nearly as friendly as just displaying
the name of that branch, especially if that branch is already local
to this repository.
git-merge now sets the environment variable 'GITHEAD_%(sha1)=%(name)'
for each argument it gets passed, making the actual input name that
resolved to the commit '%(sha1)' easily available to the invoked
merge strategy.
git-merge-recursive makes use of these environment variables when
they are available by using '%(name)' whenever it outputs the commit
identification rather than '%(sha1)'. This is most obvious in the
conflict hunks created by xdl_merge:
$ git mege sideb~1
<<<<<<< HEAD:INSTALL
Good!
=======
Oops.
>>>>>>> sideb~1:INSTALL
[jc: adjusted a test script and a minor constness glitch.]
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When we get a line-level conflict in merge-recursive and print out
the two sides in the conflict hunk header and footer we should use
the standard extended SHA1 syntax to specify the specific blob,
as this allows the user to copy and paste the line right into
'git show' to view the complete version.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This is a mechanical clean-up of the way *.c files include
system header files.
(1) sources under compat/, platform sha-1 implementations, and
xdelta code are exempt from the following rules;
(2) the first #include must be "git-compat-util.h" or one of
our own header file that includes it first (e.g. config.h,
builtin.h, pkt-line.h);
(3) system headers that are included in "git-compat-util.h"
need not be included in individual C source files.
(4) "git-compat-util.h" does not have to include subsystem
specific header files (e.g. expat.h).
Signed-off-by: Junio C Hamano <junkio@cox.net>
We broke the discipline Linus set up to allow compiler help us
avoid typos in environment names in the early days of git over
time. This defines a handful preprocessor constants for
environment variable names used in relatively core parts of the
system.
I've left out variable names specific to subsystems such as HTTP
and SSL as I do not think they are big problems.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Prior to 65ac6e9c3f we deleted a file
from the working directory during a merge if the file existed before
the merge started but was renamed by the branch being merged in.
This broke in 65ac6e as git-merge-recursive did not actually update
the working directory on an uncontested rename.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Unify the handling for cases C (add/add) and D (modify/modify).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
There are some baseless merge cases where git-merge-recursive will
try to compare one of the branches against the empty tree. However
most projects won't have the empty tree object in their object database
as Git does not normally create empty tree objects. If the empty tree
object is missing then the merge process will die, as it cannot load the
object from the database. The error message may make the user think that
their database is corrupt when its actually not.
So instead we should just create the empty tree object whenever it is
needed. If the object already exists as a loose object then no harm
done. Otherwise that loose object will be pruned away later by either
git-prune or git-prune-packed.
Thanks goes to Junio for suggesting this fix.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Read the configuration in to get core.filemode value for this
particular repository.
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The three-way merge by git-read-tree does not complain about
presense of the file in the working tree that is involved in a
merge when the merge result needs to be determined by the
caller. Adjust merge-recursive so that it makes sure that an
untracked file is not touched when the merge decides the path
should not be included in the final result.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Most callers of write_sha1_file_prepare() are only interested in the
resulting hash but don't care about the returned file name or the header.
This patch adds a simple wrapper named hash_sha1_file() which does just
that, and converts potential callers.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Alex Riesen