Merges the current head with one other commit.
In this first iteration the merge command supports
only fast forward and already up-to-date.

Change-Id: I0db480f061e01b343570cf7da02cac13a0cbdf8f
Signed-off-by: Stefan Lay <stefan.lay@sap.com>
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

The CommitCommand should take care to create a merge commit if the file
$GIT_DIR/MERGE_HEAD exists. It should then read the parents for the merge
commit out of this file. It should also take care that when commiting
a merge and no commit message was specified to read the message from
$GIT_DIR/MERGE_MSG.
Finally the CommitCommand should remove these files if the commit
succeeded.

Change-Id: 	I4e292115085099d5b86546d2021680cb1454266c
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

Ensures all translations exist in the root locale.

Change-Id: Ic8a8bdfd4a06c6d1ebd1e85a8082a32c82d155c7

The strings are externalized into the root resource bundles.
The resource bundles are stored under the new "resources" source
folder to get proper maven build.

Strings from tests are, in general, not externalized. Only in
cases where it was necessary to make the test pass the strings
were externalized. This was typically necessary in cases where
e.getMessage() was used in assert and the exception message was
slightly changed due to reuse of the externalized strings.

Change-Id: Ic0f29c80b9a54fcec8320d8539a3e112852a1f7b
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

Rather than keep track of both the position of the object, and the
position of its data, just keep track of the number of bytes used
by the object's header in the pack.  This shaves 4 bytes out of the
size of the PackedObjectLoader instances.

We also can defer the addition instruction to the materialize()
operation, avoiding it entirely if the caller never actually uses
the loader.  This may be relevant for PackWriter invocations,
where only 1 loader gets chosen for a given object, even though
the object may appear on disk in more than one pack file.

Error reporting is now simplified, as we can rely on the object
offset rather than its data offset.  This is the value displayed
by pack debugging tools like `git verify-pack -v`, so its better
to use that in our own errors.

Because nobody needs getDataOffset() now, we can drop that from
the public API.

Change-Id: Ic639c0d5a722315f4f5c8ffda6e26643d90e5f42
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Added a new package org.eclipse.jgit.api and a builder-style API for
jgit. Added also the first implementation for two git commands: Commit
and Log.

This API is intended to be used by external components when
functionalities of the standard git commands are required. It will also
help to ease writing JGit tests.

For internal usages this API may often not be optimal because the git
commands are doing much more than required or they expect parameters of
an unappropriate type.

Change-Id: I71ac4839ab9d2f848307eba9252090c586b4146b
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

The repository state tells in which state the repo is and also which actions
are currently allowed. The state MERGING is telling that a commit is not
possible. But this is only true in the case of unmerged paths in the index.
When we are merging but have resolved all conflicts then we are in a special
state: We are still merging (means the next commit should have multiple
parents) but a commit is now allowed.

Since the MERGING state "canCommit()" cannot be enhanced to return true/false
based on the index state (MERGING is an enum value which does not have a
reference to the repository its state it is representing) I had to introduce a new
state MERGING_RESOLVED. This new state will report that a commit is possible.

CAUTION: there might be the chance that users of jgit previously blindly did a
plain commit (with only one parent) when the RepositoryState allowed them to
do so. With this change these users will now be confronted with a RepositoryState
which says a commit is possible but before they can commit they'll have to
check the MERGE_MESSAGE and MERGE_HEAD files and use the info from these
files.

Change-Id: I0a885e2fe8c85049fb23722351ab89cf2c81a431
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

If two keys are the same length, but don't share the same sequence
of characters, we were incorrectly claiming they still matched due
to a bug in the for loop condition.  I used the wrong variable and
the loop never executed, resulting in equality anytime the two keys
being compared were the same length.

Use the proper local variable to loop through the arrays, and add
a JUnit test to verify equality works as expected.

Change-Id: I4a02400e65a9b2e0da925b05a2cc4b579e1dd33a
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The pack files were left open after the test ended, which meant
we could not delete them automatically when the test was over.

Make sure we close the repositories (and thus their underlying packs)
before the tear down finishes.

Bug: 310367
Change-Id: I4d2703efa4b2e0c347ea4f4475777899cf71073e
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This option was mis-named from day 1.  Its not checking that the
objects provided by the client are reachable, its actually doing
a scan to prove that objects referenced by the client are already
reachable through another reference on the server, or were sent
as part of the pack from the client.

Rename it checkReferencedObjectsAreReachable, since we really are
trying to validate that objects referenced by the client's actions
are reachable to the client.

We also need to ensure we run checkConnectivity() anytime this is
enabled, even if the caller didn't turn on fsck for object formats.
Otherwise the check would be completely bypassed.

Change-Id: Ic352ddb0ca8464d407c6da5c83573093e018af19
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If ensureProvidedObjectsVisible is enabled we expected any trees or
blobs directly reachable from an advertised reference to be marked
with UNINTERESTING.  Unfortunately ObjectWalk doesn't bother setting
this until the traversal is complete.  Even then it won't necessarily
set it on every tree if the corresponding commit wasn't popped.

When we are going to check the base objects for the received pack,
ensure the UNINTERESTING flag gets carried into every immediately
reachable tree or blob, because these are the ones that the client
might try to use as delta bases in a thin pack.

Change-Id: I5d5fdcf07e25ac9fc360e79a25dff491925e4101
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If we need to append less than 20 bytes in order to fix a thin pack
and make it complete, we need to set the length of our file back to
the actual number of bytes used because the original SHA-1 footer was
not completely overwritten.  That extra data will confuse the header
and footer fixup logic when it tries to read to the end of the file.

This isn't a very common case to occur, which is why we've never
seen it before.  Getting a delta that requires a whole object which
uses less than 20 bytes in pack representation is really hard.
Generally a delta generator won't make these, because the delta
would be bigger than simply deflating the whole object.  I only
managed to do this with a hand-crafted pack file where a 1 byte
delta was pointed to a 1 byte whole object.

Normally we try really hard to avoid truncating, because its
typically not safe across network filesystems.  But the odds of
this occurring are very low.  This truncation is done on a file
we have open for writing, will append more content onto, and is
a temporary file that we won't move into position for others to
see until we've validated its SHA-1 is sane.  I don't think the
truncate on NFS issue is something we need to worry about here.

Change-Id: I102b9637dfd048dc833c050890d142f43c1e75ae
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The JSch bundle in Eclipse 3.4 does not export its packages with
version numbers. Use Require-Bundle on version 0.1.37 that comes
with Eclipse 3.4

There is no 0.1.37 in the maven repositories so the pom still refers
to 0.1.41 so the build can get the compile time dependencies right.

Bug: 308031
CQ: 3904 jsch Version: 0.1.37 (using Orbit CQ2014)

Change-Id: I12eba86bfbe584560c213882ebba58bf1f9fa0c1
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

RawParseUtils.parsePersonIdent handles now those invalid byte sequences
which would result in IndexOutOfBoundsException and returns null in this
case.

Change-Id: Ifad1a5a6f2909d709fd7834b32b9b9949b2e5633
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Change-Id: Ica516f1e34335ca7a05b071fd527027b10bb7e73
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Since the API is changing relative to 0.7.0, we'll call our next
release 0.8.1.  But until that gets released, builds from master
will be 0.8.0.qualifier.

Change-Id: I921e984f51ce498610c09e0db21be72a533fee88
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Change-Id: I5afdc624b28fab37b28dd2cc71d334198672eef3
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Change-Id: I9b00a4041c19115e81326afd2213b98603f789ad

Some transports actually provide stream buffering on their own,
without needing to be wrapped up inside of a BufferedInputStream in
order to smooth out system calls to read or write.  A great example
of this is the JSch SSH client, or the Apache MINA SSHD server.
Both use custom buffering to packetize the streams into the encrypted
SSH channel, and wrapping them up inside of a BufferedInputStream
or BufferedOutputStream is relatively pointless.

Our SideBandOutputStream implementation also provides some fairly
large buffering, equal to one complete side-band packet on the main
data channel.  Wrapping that inside of a BufferedOutputStream just to
smooth out small writes from PackWriter causes extra data copies, and
provides no advantage.  We can save some memory and some CPU cycles
by letting PackWriter dump directly into the SideBandOutputStream's
internal buffer array.

Instead we push the buffering streams down to be as close to the
network socket (or operating system pipe) as possible.  This allows
us to smooth out the smaller reads/writes from pkt-line messages
during advertisement and negotation, but avoid copying altogether
when the stream switches to larger writes over a side band channel.

Change-Id: I2f6f16caee64783c77d3dd1b2a41b3cc0c64c159
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Instead of relying on our callers to wrap us up inside of a
BufferedOutputStream and using the proper block sizing, do the
buffering directly inside of SideBandOutputStream.  This ensures
we don't get large write-throughs from BufferedOutputStream that
might overflow the configured packet size.

The constructor of SideBandOutputStream is also beefed up to check
its arguments and ensure they are within acceptable ranges for the
current side-band protocol.

Change-Id: Ic14567327d03c9e972f9734b8228178bc448867d
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The tests were using a Locale.ROOT constant which was introduced
in Java 6.  However, we need to retain Java 5 support.

Change-Id: I75c5648fcfc728a9aea2e839d2ad0320f5cf742f
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Sasa Zivkov <sasa.zivkov@sap.com>

The support for NLS relies on java.util API to load a standard
ResourceBundle and then uses java reflection API to inject localized
strings into public String fields of the corresponding instance
of TranslationBundle.

Locale setting is supported per thread to enable concurrent threads
to use different locales. This is useful when JGit runs in a server
context where (error) messages might need to differ per-request to
suit the user's preference.

Change-Id: Ie0e63a0d7bb74eaad495dbe8248595d8a3a76883
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

If the build server is really busy, we might wait longer than 250 ms
before being interrupted, simply because one of our threads couldn't
be scheduled onto a CPU.  Don't make that cause a test failure.
Instead tolerate longer than expected waits, but not shorter waits.

Change-Id: I64511eec24b49e33928451e4c8b8c124eddaf0c2
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

A 0 file mode in a DirCacheEntry is not a valid mode.  To C git
such a value indicates the record should not be present.  We already
were catching this bad state and exceptioning out when writing tree
objects to disk, but we did not fail when writing the dircache back
to disk.  This allowed JGit applications to create a dircache file
which C git would not like to read.

Instead of checking the mode during writes, we now check during
mutation.  This allows application bugs to be detected sooner and
closer to the cause site.  It also allows us to avoid checking most
of the records which we read in from disk, as we can assume these
are formatted correctly.

Some of our unit tests were not setting the FileMode on their test
entry, so they had to be updated to use REGULAR_FILE.

Change-Id: Ie412053c390b737c0ece57b8e063e4355ee32437
Originally: http://thread.gmane.org/gmane.comp.version-control.git/128214/focus=128213
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Adam W. Hawks <awhawks@writeme.com>

Actually set the range of versions we are willing to accept for
each package we import, lest we import something in the future
that isn't compatible with our needs.

Change-Id: I25dbbb9eaabe852631b677e0c608792b3ed97532
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The supplied test case comes out of the example tree identified by
Robert de Wilde and Ilari on #git:

  $ git ls-tree -rt a54f1a85eb
  040000 tree bfe058ad53    A
  040000 tree 4b825dc642    A/A
  040000 tree 4b825dc642    A/B
  100644 blob abbbfafe31    B

In this tree, "B" was being skipped because "A/A" as an empty tree
was immediately followed by "A/B", also an empty tree, but the
ObjectWalk broke out too early and never visited "B".

Bug: 286653
Change-Id: I25bcb0bc99d0cbbbdd9c2bd625ad6a691a6d0335
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

We didn't skip the correct number of bytes when we skipped over an
unrecognized but optional dircache extension.  We missed skipping
the 8 byte header that makes up the extension's name and length.

We also didn't include the skipped extension's payload as part of
our index checksum, resuting in a checksum failure when the index
was done reading.  So ensure we always scan through a skipped
section and include it in the checksum computation.

Add a test case for a currently unsupported index extension, 'ZZZZ',
to verify we can still read the DirCache object even though we
don't know what 'ZZZZ' is supposed to mean.

Bug: 301287
Change-Id: I4bdde94576fffe826d0782483fd98cab1ea628fa
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This test doesn't actually depend upon the large data set we have
in the RepositoryTestCase, so drop that from the dependency and
use the more simple LocalDiskRepositoryTestCase instead.

Change-Id: I0fd4affe1dd5ec86e8c3253db42df11d3b612e36
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The unsetSection method can be used to delete an entire configuration
block, such as a [branch ""] or [remote ""] section in a file.

Change-Id: I93390c9b2187eb1b0d51353518feaed83bed2aad
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

Config was confusing the following two variables when writing the
file back to text format:

  [my]
    empty =
    enabled

When parsed, we say that my.empty has 1 value, null, and my.enabled
is an empty string value that in boolean context should be evaluated
as true.

Saving this configuration file back to text format was ignoring the
null value for my.empty, producing a completely different file than
what Config read:

  [my]
    empty
    enabled

Instead handle the writing differently to ensure the original format
is output.  New tests cases cover the expected behavior and return
values from accessor methods.

Change-Id: Id37379ce20cb27e3330923cf989444dd9f2bdd96
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Annotated tags created with C Git versions before the introduction
of c818566 ([PATCH] Update tags to record who made them, 2005-07-14),
do not have a "tagger" line present in the object header.  This line
did not appear in C Git until v0.99.1~9.

Ancient projects such as the Linux kernel contain such tags, for
example Linux 2.6.12 is older than when this feature first appeared
in C Git.  Linux v2.6.13-rc4 in late July 2005 is the first kernel
version tag to actually contain a tagger line.

It is therefore acceptable for the header to be missing, and for
the RevTag.getTaggerIdent() method to return null.

Since the Javadoc for getTaggerIdent() already explained that the
identity may be null, we just need to test that this is true when
the header is missing, and allow the ObjectChecker to pass anyway.

Change-Id: I34ba82e0624a0d1a7edcf62ffba72260af6f7e5d
See: http://code.google.com/p/gerrit/issues/detail?id=399
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Technically our project name is "JGit", not "Java Git".  In fact
there is already another project called "JavaGit" (no space) that we
don't want to become confused with.  Ensure we always call ourselves
"JGit" in user visible assets, like the bundle name.

Other Eclipse products list their provider as "Eclipse.org",
not "eclipse.org".  So list ourselves that way in all of our
plugin.properties files.

Change-Id: Ibcea1cd6dda2af757a8584099619fc23b7779a84
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

By using RefUpdate for symbolic reference creation we can reuse
the logic related to updating the reflog with the event, without
needing to expose something such as the legacy ReflogWriter class
(which we no longer have).

Applications using writeSymref must update their code to use the
new pattern of changing the reference through the updateRef method:

    String refName = "refs/heads/master";
    RefUpdate u = repository.updateRef(Constants.HEAD);
    u.setRefLogMessage("checkout: moving to " + refName, false);
    switch (u.link(refName)) {
    case NEW:
    case FORCED:
    case NO_CHANGE:
        // A successful update of the reference
        break;
    default:
        // Handle the failure, e.g. for older behavior
        throw new IOException(u.getResult());
    }

Change-Id: I1093e1ec2970147978a786cfdd0a75d0aebf8010
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This commit actually does three major changes to the way references
are handled within JGit.  Unfortunately they were easier to do as
a single massive commit than to break them up into smaller units.

Disambiguate symbolic references:
---------------------------------

  Reporting a symbolic reference such as HEAD as though it were
  any other normal reference like refs/heads/master causes subtle
  programming errors.  We have been bitten by this error on several
  occasions, as have some downstream applications written by myself.

  Instead of reporting HEAD as a reference whose name differs from
  its "original name", report it as an actual SymbolicRef object
  that the application can test the type and examine the target of.

  With this change, Ref is now an abstract type with different
  subclasses for the different types.

  In the classical example of "HEAD" being a symbolic reference to
  branch "refs/heads/master", the Repository.getAllRefs() method
  will now return:

      Map<String, Ref> all = repository.getAllRefs();
      SymbolicRef HEAD = (SymbolicRef) all.get("HEAD");
      ObjectIdRef master = (ObjectIdRef) all.get("refs/heads/master");

      assertSame(master,               HEAD.getTarget());
      assertSame(master.getObjectId(), HEAD.getObjectId());

      assertEquals("HEAD",              HEAD.getName());
      assertEquals("refs/heads/master", master.getName());

  A nice side-effect of this change is the storage type of the
  symbolic reference is no longer ambiguous with the storge type
  of the underlying reference it targets.  In the above example,
  if master was only available in the packed-refs file, then the
  following is also true:

      assertSame(Ref.Storage.LOOSE,  HEAD.getStorage());
      assertSame(Ref.Storage.PACKED, master.getStorage());

  (Prior to this change we returned the ambiguous storage of
   LOOSE_PACKED for HEAD, which was confusing since it wasn't
   actually true on disk).

  Another nice side-effect of this change is all intermediate
  symbolic references are preserved, and are therefore visible
  to the application when they walk the target chain.  We can
  now correctly inspect chains of symbolic references.

  As a result of this change the Ref.getOrigName() method has been
  removed from the API.  Applications should identify a symbolic
  reference by testing for isSymbolic() and not by using an arcane
  string comparsion between properties.

Abstract the RefDatabase storage:
---------------------------------

  RefDatabase is now abstract, similar to ObjectDatabase, and a
  new concrete implementation called RefDirectory is used for the
  traditional on-disk storage layout.  In the future we plan to
  support additional implementations, such as a pure in-memory
  RefDatabase for unit testing purposes.

Optimize RefDirectory:
----------------------

  The implementation of the in-memory reference cache, reading, and
  update routines has been completely rewritten.  Much of the code
  was heavily borrowed or cribbed from the prior implementation,
  so copyright notices have been left intact as much as possible.

  The RefDirectory cache no longer confuses symbolic references
  with normal references.  This permits the cache to resolve the
  value of a symbolic reference as late as possible, ensuring it
  is always current, without needing to maintain reverse pointers.

  The cache is now 2 sorted RefLists, rather than 3 HashMaps.
  Using sorted lists allows the implementation to reduce the
  in-memory footprint when storing many refs.  Using specialized
  types for the elements allows the code to avoid additional map
  lookups for auxiliary stat information.

  To improve scan time during getRefs(), the lists are returned via
  a copy-on-write contract.  Most callers of getRefs() do not modify
  the returned collections, so the copy-on-write semantics improves
  access on repositories with a large number of packed references.

  Iterator traversals of the returned Map<String,Ref> are performed
  using a simple merge-join of the two cache lists, ensuring we can
  perform the entire traversal in linear time as a function of the
  number of references: O(PackedRefs + LooseRefs).

  Scans of the loose reference space to update the cache run in
  O(LooseRefs log LooseRefs) time, as the directory contents
  are sorted before being merged against the in-memory cache.
  Since the majority of stable references are kept packed, there
  typically are only a handful of reference names to be sorted,
  so the sorting cost should not be very high.

  Locking is reduced during getRefs() by taking advantage of the
  copy-on-write semantics of the improved cache data structure.
  This permits concurrent readers to pull back references without
  blocking each other.  If there is contention updating the cache
  during a scan, one or more updates are simply skipped and will
  get picked up again in a future scan.

  Writing to the $GIT_DIR/packed-refs during reference delete is
  now fully atomic.  The file is locked, reparsed fresh, and written
  back out if a change is necessary.  This avoids all race conditions
  with concurrent external updates of the packed-refs file.

  The RefLogWriter class has been fully folded into RefDirectory
  and is therefore deleted.  Maintaining the reference's log is
  the responsiblity of the database implementation, and not all
  implementations will use java.io for access.

  Future work still remains to be done to abstract the ReflogReader
  class away from local disk IO.

Change-Id: I26b9287c45a4b2d2be35ba2849daa316f5eec85d
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

These types can be used by RefDatabase implementations to manage
the collection.

A RefList stores items sorted by their name, and is an immutable
type using copy-on-write semantics to perform modifications to
the collection.  Binary search is used to locate an existing item
by name, or to locate the proper insertion position if an item does
not exist.

A RefMap can merge up to 3 RefList collections at once during its
entry iteration, allowing items in the resolved or loose RefList
to override items by the same name in the packed RefList.

The RefMap's goal is O(log N) lookup time, and O(N) iteration time,
which is suitable for returning from a RefDatabase.  By relying on
the immutable RefList we might be able to make map construction
nearly constant, making Repository.getAllRefs() an inexpensive
operation if the caches are current.  Since modification is not
common, changes require up to O(N + log N) time to copy the internal
list and collapse or expand the list's array.  As most changes
are made to the loose collection and not the packed collection,
in practice most changes would require less than the full O(N)
time, due to a significantly smaller N in the loose list.

Almost complete test coverage is included in the corresponding
unit tests.  A handful of methods on RefMap are not tested in this
change, as writing the proper test depends on a future refactoring
of how the Ref class represents symbolic reference names.

Change-Id: Ic2095274000336556f719edd75a5c5dd6dd1d857
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Not all occurrences of ".git" are replaced by this constant, only
those where it actually refers to the directory with that name, i.e
not the ".git" directory suffix.

Asserts and comment are also excluded from replacement.

Change-Id: I65a9da89aedd53817f2ea3eaab4f9c2bed35d7ee
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

Later we are going to add support for smart HTTP, which requires us to
buffer at least some of the request created by a client before we ship
it to the server.  For many requests, we can fit it completely into a
1 MiB buffer, but if it doesn't we can drop back to using the chunked
transfer encoding to send an unknown stream length.

Rather than recoding the block based memory buffer, we refactor the
local file overflow strategy into a subclass, allowing the HTTP client
code to replace this portion of the logic with its own approach to
start the chunked encoding request.

Change-Id: Iac61ea1017b14e0ad3c4425efc3d75718b71bb8e
Signed-off-by: Shawn O. Pearce <sop@google.com>

The multi_ack_detailed extension breaks out the "ACK %s continue" status
code into "ACK %s common" and "ACK %s ready" states, making it easier to
discover which objects are truely common, and which objects are simply
on a chain the server doesn't care learning about.

Change-Id: Ie8e907424cfbbba84996ca205d49eacf339f9d04
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

These routines create a fairly clean DSL for writing out the
structure of a repository in a test case.  Abstract them into
a helper class that we can reuse in other test environments.

Change-Id: I55cce3d557e1a28afe2fdf37b3a5b67e2651c9f1
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Other test suites may find this useful, especially when trying
to defeat the pack file compression with random data files.

Change-Id: Ic00a4ac626af7a1c94d18ee99305e295b267b1a3
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Since Robin reverted using the maven-bundle-plugin to produce the
OSGi manifest, there is no reason for us to reference it from our
build process anymore.

Also, when Robin reverted the to the Eclipse way of doing things,
we failed to update the ignore files to ignore our generated files
but not ignore our tracked .classpath.

Finally, we cannot delete the MANIFEST.MF file during a Maven build,
as this is once again a source file.

Change-Id: I53f77f2002cb4285f728968829560e835651e188
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This restores the ability to build using just Eclipse without
strange procedures, extra plugins and it is again possible to
work on both JGit and EGit in the same Eclipse workspace with
ease.

Change-Id: I0af08127d507fbce186f428f1cdeff280f0ddcda
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

Adds the file content merge alorithm and tests for merge to jgit.
The merge algorithm:

- Gets as input parameters the common base, the two new contents
  called "ours" and "theirs".

- Computes the Edits from base to ours and from base to theirs with
  the help of MyersDiff.

- Iterates over the edits.

- Independent edits from ours or from theirs will just be applied
  to the result.

- For conflicting edits we first harmonize the ranges of the edits
  so that in the end we have exactly two edits starting and ending
  at the same points in the common base. Then we write the two
  conclicting contents into the result stream.

Change-Id: I411862393e7bf416b6f33ca55ec5af608ff4663
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
[sp: Fixed up two awkard comments in documentation.]
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

We call it "JGit Format", not "JGit".

Change-Id: Idd20557d21fe20602c00a60bfeaea78d3c95fe5e
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The UnionInputStream utility class combines multiple sequential
InputStreams so they appear to the caller as a single stream with
no gaps.  This can be used to concentate streams coming from multiple
independent HTTP connections (for example).

The companion unit test covers the class's full functionality.

Change-Id: I0676c7b5e082a5886bf0e8f43f9fd6c46a666228
Signed-off-by: Shawn O. Pearce <sop@google.com>

Tycho isn't production ready for projects like JGit to be using as
their primary build driver.  Some problems we ran into with Tycho
0.6.0 that are preventing us from using it are:

 * Tycho can't run offline

   The P2 artifact resolver cannot perform its work offline.  If the
   build system has no network connection, it cannot compile a
   project through Tycho.  This is insane for a distributed version
   control system where developers are used to being offline during
   development and local testing.

 * Magic state in ~/.m2/repository/.meta/p2-metadata.properties

   Earlier iterations of this patch tried to use a hybrid build,
   where Tycho was only used for the Eclipse specific feature and P2
   update site, and maven-bundle-plugin was used for the other code.
   This build seemed to work, but only due to magic Tycho specific
   state held in my local home directory.  This means builds are not
   consistently repeatable across systems, and lead me to believe
   I had a valid build, when in fact I did not.

 * Manifest-first build produces incomplete POMs

   The POM created by the manifest-first build format does not
   contain the dependency chain, leading a downstream consumer to
   not import the runtime dependencies necessary to execute the
   bundle it has imported.  In JGit's case, this means JSch isn't
   included in our dependency chain.

 * Manifest-first build produces POMs unreadable by Maven 2.x

   JGit has existing application consumers who are relying on
   Maven 2.x builds.  Forcing them to step up to an alpha release
   of Maven 3 is simply unacceptable.

 * OSGi bundle export data management is tedious

   Editing each of our pom.xml files to mark a new release is
   difficult enough as it is.  Editing every MANIFEST.MF file to
   list our exported packages and their current version number is
   something a machine should do, not a human.  Yet the Tycho OSGi
   way unfortunately demands that a human do this work.

 * OSGi bundle import data management is tedious

   There isn't a way in the MANIFEST.MF file format to reuse the
   same version tags across all of our imports, but we want to have
   a consistent view of our dependencies when we compile JGit.

After wasting more than 2 full days trying to get Tycho to work,
I've decided its a lost cause right now.  We need to be chasing down
bugs and critical features, not trying to bridge the gap between
the stable Maven repository format and the undocumented P2 format
used only by Eclipse.

So, switch the build to use Apache Felix's maven-bundle-plugin.

This is the same plugin Jetty uses to produce their OSGi bundle
manifests, and is the same plugin used by the Apache Felix project,
which is an open-source OSGi runtime.  It has a reasonable number
of folks using it for production builds, and is running on top of
the stable Maven 2.x code base.

With this switch we get automatically generated MANIFEST.MF files
based on reasonably sane default rules, which reduces the amount
of things we have to maintain by hand.  When necessary, we can add
a few lines of XML to our POMs to tweak the output.

Our build artifacts are still fully compatible with Maven 2.x, so
any downstream consumers are still able to use our build products,
without stepping up to Maven 3.x.  Our artifacts are also valid as
OSGi bundles, provided they are organized on disk into a repository
that the runtime can read.

With maven-bundle-plugin the build runs offline, as much as Maven
2.x is able to run offline anyway, so we're able to return to a
distributed development environment again.

By generating MANIFEST.MF at the top level of each project (and
therefore outside of the target directory), we're still compatible
with Eclipse's PDE tooling.  Our projects can be imported as standard
Maven projects using the m2eclipse plugin, but the PDE will think
they are vaild plugins and make them available for plugin builds,
or while debugging another workbench.

This change also completely removes Tycho from the build.

Unfortunately, Tycho 0.6.0's pom-first dependency resolver is broken
when resolving a pom-first plugin bundle through a manifest-first
feature package, so bundle org.eclipse.jgit can't be resolved,
even though it might actually exist in the local Maven repository.

Rather than fight with Tycho any further, I'm just declaring it
plugina-non-grata and ripping it out of the build.

Since there are very few tools to build a P2 format repository, and
no documentation on how to create one without running the Eclipse
UI manually by poking buttons, I'm declaring that we are not going
to produce a P2 update site from our automated builds.

Change-Id: If7938a86fb0cc8e25099028d832dbd38110b9124
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This makes the jgit command line behave like the C Git implementation
in the respect.

These variables are not recognized in the core, though we add support
to do the overrides there. Hence other users of the JGit library, like
the Eclipse plugin and others, will not be affected.

GIT_DIR
	The location of the ".git" directory.

GIT_WORK_TREE
	The location of the work tree.

GIT_INDEX_FILE
	The location of the index file.

GIT_CEILING_DIRECTORIES
	A colon (semicolon on Windows) separated list of paths that
	which JGit will not cross when looking for the .git directory.

GIT_OBJECT_DIRECTORY
	The location of the objects directory under which objects are
	stored.

GIT_ALTERNATE_OBJECT_DIRECTORIES
	A colon (semicolon on Windows) separated list of object directories
	to search for objects.

In addition to these we support the core.worktree config setting when
the git directory is set deliberately instead of being found.

Change-Id: I2b9bceb13c0f66b25e9e3cefd2e01534a286e04c
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

An extra flag when creating a RefUpdate object allows the
caller to destroy the symref and replace it with an object
ref, a.k.a. detached HEAD.

Change-Id: Ia88d48eab1eb4861ebfa39e3be9258c3824a19db
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The test data is expected to have unix new lines by tests, but it
is converted to crlf on Windows platform (with msys git). As result
DiffFormatterReflowTest tests fail. To prevent this problem,
crlf conversion is disbled for test data related to that test.

Bug: 295077
Change-Id: I67d3ed543fcc38647041896146de12b1781ec6be
Signed-off-by: Constantine Plotnikov <constantine.plotnikov@gmail.com>