"Auth fail" exception was swallowed during retrying, this leads to
"Session down" exception during clone operation with invalid SSH keys.

Bug: 336795
Change-Id: Id8d9e83b10f4f2a01e0cf89819190bb23a04a2b9
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>

Change-Id: I763590a45d75f00a09097ab6f89581a3bbd3c797

When SSH user/password authentication failed this may have been caused
by changed credentials on the server side. When the SSH credentials of a
user change the SSH connection needs to be re-established and
credentials which may have been stored by the credentials provider
need to be reset in order to enable prompting for the new credentials.

Bug: 356233
Change-Id: I7d64c5f39b68a9687c858bb68a961616eabbc751
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

The RemoteSession interface operates like a simplified version of
java.lang.Runtime with a single exec method (and a disconnect
method). It returns a java.lang.Process, which should begin execution
immediately. Note that this greatly simplifies the interface for
running commands. There is no longer a connect method, and most
implementations will contain the bulk of their code inside
Process.exec, or a constructor called by Process.exec. (See the
revised implementations of JschSession and ExtSession.)
Implementations can now configure their connections properly without
either ignoring the proper use of the interface or trying to adhere
to an overly strict interface with odd rules about what methods are
called first.  For example, Jsch needs to create the output stream
before executing, which it now does in the process constructor. These
changes should make it much easier to add alternate session
implementations in the future.

Also-by: John D Eblen <jdeblen@comcast.net>
Bug: 336749
CQ: 5004
Change-Id: Iece43632086afadf175af6638255041ccaf2bfbb
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

When setting up an SSH connection, use the caller supplied
CredentialsProvider, if one has been given to the Transport
or was defined as the default.

The CredentialsProvider is re-wrapped as a JSch UserInfo,
allowing the connection to use this for user interactive
prompts.  This give a unified API for authentication on
any transport type.

Change-Id: Id3b4cf5bfd27a23207cdfb188bae3b78e71e02c0
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

On Windows, FS_Win32_Cygwin has been used if a Cygwin Git installation
is present in the PATH. Assuming that the user works with the Cygwin
Git installation may result in unnecessary overhead if he actually
does not.

Applications built on top of jgit may have more knowledge on the
actually used Git client (Cygwin or not) and hence should be able to
configure which FS to use accordingly.

Change-Id: Ifc4278078b298781d55cf5421e9647a21fa5db24

Per CQ 3448 this is the initial contribution of the JGit project
to eclipse.org.  It is derived from the historical JGit repository
at commit 3a2dd9921c.

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