Move the implementation of the static equals() method to a new method
and suppress the error. Deprecate the old method to signal that we
intend to remove it in the next major release.

See https://errorprone.info/bugpattern/AmbiguousMethodReference

Change-Id: I5e29c97f4db3e11770be589a6ccd785e2c9ac7f2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Error Prone reports:

  [NarrowingCompoundAssignment] Compound assignments from long to int
  hide lossy casts

and

  [NarrowingCompoundAssignment] Compound assignments from int to byte
  hide lossy casts

  See https://errorprone.info/bugpattern/NarrowingCompoundAssignment

Fix the warnings by adding explicit casts or changing types as
necessary.

Now that all occurrences of the warning are fixed, increase its
severity to ERROR.

Change-Id: Idb3670e6047b146ae37daee07212ff9455512623
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

- use FS.DETECTED instead of db.getFS() since the ssh config is
typically in a different place than the repository, the same is used in
OpenSshConfig
- reduce unnecessary repeated writes by introducing wait for one tick of
the file time resolution

Change-Id: Ifac915e97ff420ec5cf8e2f162e351f9f51b6b14
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Increase the safety factor to 2.5x for extra safety if max of measured
timestamp resolution and measured minimal racy threshold is < 100ms, use
1.25 otherwise since for large filesystem resolution values the
influence of finite resolution of the system clock should be negligible.

Before, not yet using the newly introduced minRacyThreshold measurement,
the threshold was 1.1x FS resolution, and we could issue the
following sequence of events,

  start
  create-file
  read-file (currentTime)
  end

which had the following timestamps:

  create-file 1564589081
  start 1564589082
  read 1564589082
  end 1564589082

In this case, the difference between create-file and read is 5ms,
which exceeded the 4ms FS resolution, even though the events together
took just 2ms of runtime.

Reproduce with:
  bazel test --runs_per_test=100 \
    //org.eclipse.jgit.test:org_eclipse_jgit_internal_storage_file_FileSnapshotTest

The file system timestamp resolution is 4ms in this case.

This code assumes that the kernel and the JVM use the same clock that
is synchronized with the file system clock. This seems plausible,
given the resolution of System.currentTimeMillis() and the latency for
a gettimeofday system call (typically ~1us), but it would be good to
justify this with specifications.

Also cover a source of flakiness: if the test runs under extreme load,
then we could have

  start
  create-file
  <long delay>
  read
  end

which would register as an unmodified file. Avoid this by skipping the
test if end-start is too big.

[msohn]:
- downported from master to stable-5.1
- skip test if resolution is below 10ms
- adjust safety factor to 1.25 for resolutions above 100ms

Change-Id: I87d2cf035e01c44b7ba8364c410a860aa8e312ef
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Cache FileStoreAttributeCache entries since looking up FileStore for a
file may be expensive on some platforms.

Implement a simple LRU cache based on ConcurrentHashMap using a simple
long counter to order access to cache entries.

Change-Id: I4881fa938ad2f17712c05da857838073a2fc4ddb
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Marc Strapetz <marc.strapetz@syntevo.com>
Also-By: Marc Strapetz <marc.strapetz@syntevo.com>

To enable persisting the minimal racy threshold per FileStore add a
new config option to the user global git configuration:

- Config section is "filesystem"
- Config subsection is concatenation of
  - Java vendor (system property "java.vendor")
  - Java version (system property "java.version")
  - FileStore's name, on Windows we use the attribute volume:vsn instead
    since  the name is not necessarily unique.
  - separated by '|'
  e.g.
    "AdoptOpenJDK|1.8.0_212-b03|/dev/disk1s1"
  The same prefix is used as for filesystem timestamp resolution, so
  both values are stored in the same config section
- The config key for minmal racy threshold is "minRacyThreshold" as a
  time value, supported time units are those supported by
  DefaultTypedConfigGetter#getTimeUnit
- measure for 3 seconds to limit runtime which depends on hardware, OS
  and Java version being used

If the minimal racy threshold is configured for a given FileStore the
configured value is used instead of measuring it.

When the minimal racy threshold was measured it is persisted in the user
global git configuration.

Rename FileStoreAttributeCache to FileStoreAttributes since this class
is now declared public in order to enable exposing all attributes in one
object.

Example:

[filesystem "AdoptOpenJDK|11.0.3|/dev/disk1s1"]
	timestampResolution = 7000 nanoseconds
	minRacyThreshold = 3440 microseconds

Change-Id: I22195e488453aae8d011b0a8e3276fe3d99deaea
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Also-By: Marc Strapetz <marc.strapetz@syntevo.com>

By running FileSnapshotTest#detectFileModified we found that the sum of
measured filesystem timestamp resolution and measured clock resolution
may yield a too small interval after a file has been modified which we
need to consider racily clean. In our tests we didn't find this behavior
on all systems we tested on, e.g. on MacOS using APFS and Java 8 and 11
this effect was not observed.

On Linux (SLES 15, kernel 4.12.14-150.22-default) we collected the
following test results using Java 8 and 11:

In 23-98% of 10000 test runs (depending on filesystem type and Java
version) the test failed, which means the effective interval which needs
to be considered racily clean after a file was modified is larger than
the measured file timestamp resolution.

"delta" is the observed interval after a file has been modified but
FileSnapshot did not yet detect the modification:

"resolution" is the measured sum of file timestamp resolution and clock
resolution seen in Java.

Java version    filesystem  failures resolution  min delta   max delta
1.8.0_212-b04   btrfs	    98.6%       1 ms        3.6 ms      6.6 ms
1.8.0_212-b04   ext4        82.6%       3 ms        1.1 ms      4.1 ms
1.8.0_212-b04   xfs         23.8%       4 ms        3.7 ms      3.9 ms
1.8.0_212-b04   zfs         23.1%       3 ms        4.8 ms      5.0 ms
11.0.3+7        btrfs       98.1%       3 us        0.7 ms      4.7 ms
11.0.3+7        ext4        98.1%       6 us        0.7 ms      4.7 ms
11.0.3+7        xfs         98.5%       7 us        0.1 ms      8.0 ms
11.0.3+7        zfs         98.4%       7 us        0.7 ms      5.2 ms

Mac OS
1.8.0_212       APFS        0%          1 s
11.0.3+7        APFS        0%          6 us

The observed delta is not distributed according to a normal gaussian
distribution but rather random in the observed range between "min delta"
and "max delta".

Run this test after measuring file timestamp resolution in
FS.FileAttributeCache to auto-configure JGit since it's unclear what
mechanism is causing this effect.

In FileSnapshot#isRacyClean use the maximum of the measured timestamp
resolution and the measured "delta" as explained above to decide if a
given FileSnapshot is to be considered racily clean. Add a 30% safety
margin to ensure we are on the safe side.

Change-Id: I1c8bb59f6486f174b7bbdc63072777ddbe06694d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

These are useful to avoid typos, and also for tab completion.

Change-Id: I0f2d267e46b36bc40297c9657c447f3fd8b9f831
Signed-off-by: David Turner <dturner@twosigma.com>

In a subsequent patch, in some cases, PackWriter#writePack will be
responsible for both the "packfile-uris" and "packfile" sections,
meaning that (in these cases) it must write the "packfile" section
header itself.

In preparation for that patch, move the writing of the "packfile"
section header closer to the invocation of PackWriter#writePack when the
entire fetch response is configured to use the sideband. This means that
"packfile" is written *after* objects are counted (and progress messages
sent to the client in sideband 2) when the "sideband-all" feature is
used (whether "packfile-uris" is used or not), and written *before*
objects are counted otherwise.

Having code to write "packfile" in two places is unfortunate but
necessary. When "sideband-all" is not used, object counting has to
happen after "packfile" is written, because "packfile" activates the
sideband that allows counting progress to be transmitted. When
"packfile-uris" is used, object counting has to happen before "packfile"
is written, because object counting determines whether to send
"packfile-uris" or "packfile". When "sideband-all" is used but
"packfile-uris" is not used, either way works; this commit uses
"packfile-uris" behavior in this case.

Also make the naming of the sideband-activating methods in PacketLineOut
more consistent.

Change-Id: Ifbfd26cc26af10c41b77758168833702d6983df1
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>

Repeat the test 10000 times to get statistics if measured
fsTimestampResolution is working in practice to detect racy git
situations.

Add a class to compute statistics for this test. Log delta between
lastModified and time when FileSnapshot failed to detect modification.
This happens if the racy git limit determined by measuring filesystem
timestamp resolution and clock resolution is too small. If it would be
correct FileSnapshot would always detect modification or mark it
modified if time since modification is smaller than the racy git limit.

Change-Id: Iabe7af1a7211ca58480f8902d4fa4e366932fc77
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

The newly introduced ProtocolV2HookChain is implemented using lists
instead of arrays.

Update PostUploadHookChain to keep the hook chains implementation
consistent.

Change-Id: I5ae0c923f117ac48558a989464f5d5d868d81f76
Signed-off-by: Ivan Frade <ifrade@google.com>

The newly introduced ProtocolV2HookChain is implemented using lists
instead of arrays.

Update PostUploadHookChain to keep hook chain implementations
consistent.

Change-Id: Ic5694feab943e8949896b93103dbf427716c9bd7
Signed-off-by: Ivan Frade <ifrade@google.com>

This should help to detect if measured fsTimeResolution is too small.

Change-Id: Id1f54dbdedb52b17859904e47776fa3a5887b8be
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

When filesystem timestamp resolution is very high some tests don't work
since runtime of the test setup is too long to reach a racily clean
FileSnapshot. Hence skip these tests when timestamp resolution is higher
than 10 millisecond.

Change-Id: Ie47dd10eda22037b5c1ebff6b6becce0654ea807
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I304b2b6f2e39f72f620bba53aead60256aed3660
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

This helps to avoid some time critical tests can't prepare the test
fixture intended since measuring timestamp resolution takes time.

Change-Id: Ib34023e682a106070ca97e98ef16789a4dfb97b4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

- use Path instead of File
- create test directories, files and output stream using Files methods
- delete unused list "files"

Change-Id: I8c5c601eca9f613efb5618d33b262277df92a06a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

UploadPack only supports one protocol-v2 hook. There are already cases
where more than one is needed.

Offer a Chain class to compose ProtocolV2Hooks, as other hooks do. It
looks like a single hook but it calls all its members.

Change-Id: Idd173ca7df6672079ac0de03c67f77abac376538
Signed-off-by: Ivan Frade <ifrade@google.com>

This enables higher file timestamp resolution on filesystems like ext4,
Mac APFS (1ns) or NTFS (100ns) providing high timestamp resolution on
filesystem level.

Note:
- on some OSes Java 8,9 truncate milliseconds, see
https://bugs.openjdk.java.net/browse/JDK-8177809, fixed in Java 10
- UnixFileAttributes truncates timestamp resolution to microseconds when
converting the internal representation to FileTime exposed in the API,
see https://bugs.openjdk.java.net/browse/JDK-8181493
- WindowsFileAttributes also provides only microsecond resolution

Change-Id: I25ffff31a3c6f725fc345d4ddc2f26da3b88f6f2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Bug: 548682
Change-Id: I48840d3a68cf1db92c056d218a0d5ed0b9ea4c45
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Use a Consumer instead of several nullable variables to further
configure UploadPack. This is in preparation for a test in a subsequent
patch needing further customization of the UploadPack object before
invoking it.

Change-Id: I074dff92c711a5ba74558bb4b06c42c115fb9b7f
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>

Allow the client to specify "sideband-all" in a fetch v2 request,
indicating that the whole response is to be multiplexed (with a sideband
indicator on every non-flush and non-delim pkt) instead of only the
packfile being multiplexed. This allows, for example, progress messages
to be sent at any point in the response.

This implements the "sideband-all" feature documented in
Documentation/technical/protocol-v2.txt in Git.

Change-Id: I3e7f21c88ff0982b1b7ebb09c9ad6c742c4483c8
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>

UploadPackTest.java contains tests that check behavior when
"allowfilter" and "allowrefinwant" are not set, are set, and are not set
but the client insists on using them anyway. Because another capability
is to be included in a subsequent patch, refactor the common code in
these tests.

Remove setBoolean calls with "false", as they are no-ops.

Also take the opportunity to eliminate the overspecification of the
"fetch=" line returned by the capability advertisement.

Change-Id: I289bbd11c902a513cd8d53bc34767e61ebbd5f17
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>

Change-Id: I0a5828438810dd23790cba52d7ae2e055c6a3fc9
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

The only usage of this test iterator was removed in df637928d. Hence
delete this iterator and associated test.

Change-Id: I47710133ec3edc675c21db210960c024982668c6
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Add a unittest.

In commit I5485db55 ("Fix FileSnapshot's consideration of file size"),
the special casing of UNKNOWN_SIZE was forgotten.

This change, together with I493f3b57b ("Measure file timestamp
resolution used in FileSnapshot") introduced a regression that would
occasionally surface in Gerrit integration tests marked UseLocalDisk,
with the symptom that creating the Admin user in NoteDb failed with a
LOCK_FAILURE.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I7ffd972581f815c144f810481103c7985af5feb0

This test case assumed file system timestamp resolution of 1 second. On
filesystems with a finer resolution this test fails since the index
entry is only smudged if the file index entry's lastModified and the
lastModified of the git index itself are within the same filesystem
timer tick. Fix this by ensuring that these timestamps are identical
which should work for any filesystem timer resolution.

Bug: 548188
Change-Id: Id84d59e1cfeb48fa008f8f27f2f892c4f73985de
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

By doing this, exceptions thrown by sendPack are also covered by the
same code.

Change-Id: I3509f2d832af1410f307e931577e4d07e32b014e
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>

This is a new assertion that will be introduced in JUnit 4.13. Unlike
ExpectedException rule, this makes it easy to test other aspects of the
thrown exception, such like ServiceMayNotContinueException's status
code. Introduce this as before making changes to UploadPackTest more.

Change-Id: Ied7b3071ffcd0e93eece35b01e0abc5ff65645f2
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>

RevWalk does not currently provide a --first-parent equivalent and the
feature has been requested.

Add a field to the RevWalk class to specify whether walks should
traverse first parents only. Modify Generator implementations to support
the feature.

Change-Id: I4a9a0d5767f82141dcf6d08659d7cb77c585fae4
Signed-off-by: Dave Borowitz <dborowitz@google.com>
Signed-off-by: Alex Spradlin <alexaspradlin@google.com>

If a client clones with "--filter=blob:none", the checkout that "git
clone" automatically does causes the client to fetch all blobs at HEAD.
When fetching from a non-bitmapped repository, this will fail if an
object walk is ever needed, because JGit currently rejects such requests
- see the commit message of d3021788d2 ("Use bitmaps for non-commit
reachability checks", 2017-11-10) for more information.

Rejecting such requests in the absence of bitmaps is probably
overzealous: it is true that the server would prefer to have bitmaps in
this case, but there might be a small proportion of repos (for example,
very small repos or newly created ones) that do not have bitmaps, yet
the server would still like to have partial clones for them.

So, allow such requests, performing the object walk reachability check
if necessary. Limit this to servers with "uploadpack.allowFilter"
configured, so that servers wanting to support partial clone have this
functionality, and servers that do not support partial clone do not have
to pay the object walk reachability check cost.

Change-Id: I51964bafec68696a799625d627615b4f45ddbbbf
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>

The deleted code is not required as removed files are deleted correctly in
doCheckout() anyway.

The deleted code failed in case a non-empty directory had to be deleted.
file.delete() returned false, triggering an exception.

Bug: 479266
Change-Id: I011bb3882ff0c35b238aa3eccad7889041210277
Signed-off-by: René Scheibe <rene.scheibe@gmail.com>

Creating a folder failed in case a file with the same name already
existed.

Bug: 479266
Change-Id: Ia987660ec0968ad4081dbd5a60e80660539497e3
Signed-off-by: René Scheibe <rene.scheibe@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

By using File#setLastModified, we can create a racy git situation
stably.

Tested with --runs_per_test=100

Bug: 526111
Change-Id: I60b3632d353e19f335668325aa603640be423f58
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>

Change-Id: I621ba174235a6fb56236e54d24bce704bb5afb28
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Archives created by the ArchiveCommand didn't produce deterministic
archive hashes. For RevCommits RevWalk.parseTree returns the root tree
instead of the RevCommit hence retrieving the commit's timestamp didn't
work. Instead use RevWalk.parseAny and extract the tree manually.

Archive entries store timestamps with 1 second resolution hence we need
to wait longer when creating the same archive twice and compare archive
hashes. Otherwise hash comparison in tests wouldn't fail without this
patch.

Bug: 548312
Change-Id: I437d515de51cf68265584d28a8446cebe6341b79
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

In JDK 9 and later, the default locale data uses data derived from the
Unicode Consortium's Common Locale Data Repository (CLDR). So there are
changes with respect to some locales.

For example the short date-time format is ‹{1}, {0}› in the CLDR locale,
as opposed to {1} {0} in the JRE locale data.

See: https://bugs.openjdk.java.net/browse/JDK-8206961
See: https://www.unicode.org/cldr/charts/29/by_type/date_&_time.gregorian.html#1141bf54834c4261
Change-Id: I7535821e8ecd8702a95db8732cbbf3a4a7385eca
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

As reported by Error Prone:

An inner class should be static unless it references members of its
enclosing class. An inner class that is made non-static unnecessarily
uses more memory and does not make the intent of the class clear.

See https://errorprone.info/bugpattern/ClassCanBeStatic

Change-Id: Ib99d120532630dba63cf400cc1c61c318286fc41
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
(cherry picked from commit ee40efcea4)

Change-Id: I0644690e93c19c224c1d896fe3593f8b38901cbc
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

When cloning repository with --single-branch option, tag chains are not
packed and pack file is broken in some cases.

Typical test-case:
git tag -a test_tag <commit-id>
git tag -a test_prev_tag test_tag
git tag -d test_tag

git clone --single-branch <repository>
fatal: did not receive expected object <test_tag_id>

The reason for that is missing object for original test_tag reference,
which was deleted.

Problem description:
When pack-objects is given --include-tag, it peels each tag reference
down to a commit. If the commit is prepared to be packed, we we have to
include such tag too. The problem is when the tag points to through some
chain of other tag to commit. Then, the inner tags are not added leading
to broken pack.

Fix:
When going to commit, we have to check and add any of the tags on the
way (if they were not selected, which may happen with --single-branch
option).

Change-Id: I1682d4a2c52d674f90a1b021e0f6c3524c5ce5bc
Signed-off-by: Pavel Flaška <Pavel.Flaska@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Reported by downstream analyzers.

Change-Id: I719bb2dd5b59390973dc2eb0d6854096e3768afb
Signed-off-by: Ivan Frade <ifrade@google.com>

In a delete-modify conflict with the deletion as "ours" there may be
no stage 2 in the index. Add appropriate null checks. Add a new test
for this case, and verify that the file gets added with a single LF
after conflict resolution with core.autocrlf=true. This matches the
behavior of canonical git for this case.

Bug: 547724
Change-Id: I1bafdb83d9b78bf85294c78325e818e72fae53bc
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

The only remaining code where the return value is ignored is in tests.
Update them to store the value and perform a basic assertion.

Change-Id: I29ef5bd5dd0648aac3490f9e47ecc74544109652
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

A merging pull on an unborn branch was already supported. But a
rebasing pull failed. If the user has pull.rebase = true in his
user config, the pull would try to rebase. Rebasing needs a parent
commit, though. Native git handles this case:

  git init
  git remote add origin <URI>
  git pull --rebase origin master

Check up front in PullCommand for the unborn head and just do a
checkout in this case. MergeCommand already has similar code.

Bug: 544965
Change-Id: I1277e1ac0b0364b4623fd791f3d6b07bd5f58fca
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Canonical git treats CR-LF in config files as LF.[1][2] JGit does so,
too, except when escaped as a line continuation. Correct this and
treat the sequence \-CR-LF as a line continuation.

[1] https://github.com/git/git/commit/db2c075d9
[2] https://github.com/git/git/blob/v2.21.0/config.c#L485

Bug: 545850
Change-Id: I51e7378a22c21b3baa3701163c423d04c900af5a
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Otherwise tags may fail to match if their name contains slashes.
Canonical git also uses its wildcard matcher in glob mode.[1]

[1] https://github.com/git/git/blob/v2.21.0/builtin/describe.c#L182

Bug: 546703
Change-Id: I122c7959974fa1fc6a53dfc65837e4314a8badd4
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Commit messages of length 1 were not read. 'lineEnd' is the offset
of the last character in the line before the terminating LF or CR-LF,
and 'nextSpace' is actually the offset of the character _after_ the
next space. With a one-character commit message, nextSpace == lineEnd.

The code also assumes the commit message to be optional, but actually
failed in that case because it read beyond the line ending. Fix that,
too.

Add a test case for reading a todo file.

Bug: 546245
Change-Id: I368d63615930ea2398a6230e756442fd88870654
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Replace "size() > 0" with "!isEmpty()" where appropriate.

In the Status implementation we can drop the check; the subsequent
loop will only execute when the list is non-empty anyway.

Change-Id: I355aff551a603373e702a9d44304f087b476263c
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

The bazel build fails due to NetscapeCookieFileTest's internal class not
being visible to TransportHttpTest.

Split the file out to its own class in the util package, so it's visible
to both.

Change-Id: I69236026eecb9d08a9a66e51752a80ea522b0c6a
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

The git config entries "http.cookieFile" and
"http.saveCookies" are correctly evaluated.

Bug: 488572
Change-Id: Icfeeea95e1a5bac3fa4438849d4ac2306d7d5562
Signed-off-by: Konrad Windszus <konrad_w@gmx.de>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>