git-svn: branch: avoid systematic prompt for cert/pass

Commands such as "git svn init/fetch/dcommit" do not prompt for client
certificate/password if they are stored in SVN config file.  Make
"git svn branch" consistent with the other commands, as SVN::Client is
capable of building its own authentication baton from information in the
SVN config directory.

Signed-off-by: Monard Vong <travelingsoul86@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
git svn: info: correctly handle absolute path args

Calling "git svn info $(pwd)" would hit:
  "Reading from filehandle failed at ..."
errors due to improper prefixing and canonicalization.

Strip the toplevel path from absolute filesystem paths to ensure
downstream canonicalization routines are only exposed to paths
tracked in git (or SVN).

v2:
  Thanks to Andrej Manduch for originally noticing the issue
  and fixing my original version of this to handle
  more corner cases such as "/path/to/top/../top" and
  "/path/to/top/../top/file" as shown in the new test cases.

v3:
  Fix pathname portability problems pointed out by Johannes Sixt
  with a hint from brian m. carlson.

Cc: Johannes Sixt <j6t@kdbg.org>
Cc: "brian m. carlson" <sandals@crustytoothpaste.net>
Signed-off-by: Andrej Manduch <amanduch@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
git-svn.txt: Remove mentions of repack options

Git no longer seems to use these flags or their associated config keys;
when they are present, git-svn outputs a message indicating that they
are being ignored.

Signed-off-by: Lawrence Velázquez <vq@larryv.me>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
git svn: find-rev allows short switches for near matches

Allow -B and -A to act as short aliases for --before and --after
options respectively.  This reduces typing and hopefully allows
reuse of muscle memory for grep(1) users.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
git-svn: delay term initialization

On my Debian 7 system, this fixes annoying warnings when the output
of "git svn" commands are redirected:

    Unable to get Terminal Size. The TIOCGWINSZ ioctl didn't work.
    The COLUMNS and LINES environment variables didn't work. The
    resize program didn't work.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
print an error when remote helpers die during capabilities

The transport-helper code generally relies on the
remote-helper to provide an informative message to the user
when it encounters an error. In the rare cases where the
helper does not do so, the output can be quite confusing.
E.g.:

  $ git clone https://example.com/foo.git
  Cloning into 'foo'...
  $ echo $?
  128
  $ ls foo
  /bin/ls: cannot access foo: No such file or directory

We tried to address this with 81d340d (transport-helper:
report errors properly, 2013-04-10).

But that makes the common case much confusing. The remote
helper protocol's method for signaling normal errors is to
simply hang up. So when the helper does encounter a routine
error and prints something to stderr, the extra error
message is redundant and misleading. So we dropped it again
in 266f1fd (transport-helper: be quiet on read errors from
helpers, 2013-06-21).

This puts the uncommon case right back where it started. We
may be able to do a little better, though. It is common for
the helper to die during a "real" command, like fetching the
list of remote refs. It is not common for it to die during
the initial "capabilities" negotiation, right after we
start. Reporting failure here is likely to catch fundamental
problems that prevent the helper from running (and reporting
errors) at all. Anything after that is the responsibility of
the helper itself to report.