difftool: parse options using Getopt::Long

Replace custom option/argument parser with standard Getopt::Long
module.  This shortens the code and makes it easier to understand.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: add '--no-gui' option

This commit teaches difftool to handle the '--no-gui' option. This option
negates the existing '--gui' option. The last setting given on the command
line wins.

This allows a user to configure "[alias] mdt = difftool --gui", but still
have the ability to override the setting without error:

$ git mdt --no-gui

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: exit(0) when usage is printed

Prior to this commit, the script exited with an error whenever the
usage string was printed, regardless of the reason it was done. In
cases where usage was printed due to a user request (e.g. '-h'
option), the script should exit without error (exit 0).

This commit adds an argument to the usage function that allows the
exit code to be specified when the function is called.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: remove explicit change of PATH

Adding the script directory to PATH is not needed. The script is
located at '$(git --exec-path)', which is already on the PATH.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: stop appending '.exe' to git

The system call to Git works the same whether or not ".exe" is
appended to "git". The extra code is not necessary.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: eliminate setup_environment function

Removing this function shortens the code and makes it easier to read.
Now all environment variables are set as part of procedural operation.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: teach difftool to handle directory diffs

When 'difftool' is called to compare a range of commits that modify
more than one file, it opens a separate instance of the diff tool for
each file that changed.

The new '--dir-diff' option copies all the modified files to a temporary
location and runs a directory diff on them in a single instance of the
diff tool.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: print list of valid tools with '--tool-help'

Since bc7a96a (mergetool--lib: Refactor tools into separate files,
2011-08-18), it is possible to add a new diff tool by creating a simple
script in the '$(git --exec-path)/mergetools' directory.  Updating the
difftool help text is still a manual process, and the documentation can
easily go out of sync.

This commit teaches difftool the '--tool-help' option, which:
  - Reads the list of valid tools from 'mergetools/*'
  - Determines which of them are actually installed
  - Determines which are capable of diffing (i.e. not just a merge tool)
  - Prints the resulting list for the user

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
log-tree: use custom line terminator in line termination mode

When using a custom format in line termination mode (as opposed to line
separation mode), the configured line terminator is not used, so things
like "git log --pretty=tformat:%H -z" do not work properly.

Make it use the line terminator the user ordered.

Signed-off-by: Jan Krüger <jk@jk.gs>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
log-tree: the previous one is still not quite right

The correct output would have NUL after each commit, so "-z --format=%s"
would have a single-liner subject with the line-terminating LF replaced
with NUL, and "-p/--stat -z --format=%s" would have a single-liner subject
with its line-terminating LF, followed by the diff/diffstat in which the
terminating LF of the last line is replaced with NUL, but to be consistent
with what "-p/--stat -z --pretty=format:%s" does, I think it is OK to
append NUL to the diff/diffstat part instead of replacing its last LF with
NUL.

The added test shows the update is still not right for "-p -z --format".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4006: Windows do not have /dev/zero

We only need to have a file with _some_ binary contents; be nice to
our Windows friends and avoid using /dev/zero

Signed-off-by: Johannes Sixt <j.sixt@viscovery.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'zj/diff-empty-chmod' into next

Portability fix-up for windows.

By Johannes Sixt
* zj/diff-empty-chmod:
  t4006: Windows do not have /dev/zero
Merge branch 'th/difftool-diffall' into next

Roll the two-directory-diff logic from diffall script (in contrib/) into
"git difftool" framework.

By Tim Henigan
* th/difftool-diffall:
  difftool: print list of valid tools with '--tool-help'
  difftool: teach difftool to handle directory diffs
  difftool: eliminate setup_environment function
  difftool: stop appending '.exe' to git
  difftool: remove explicit change of PATH
  difftool: exit(0) when usage is printed
  difftool: add '--no-gui' option
  difftool: parse options using Getopt::Long
Merge branch 'jk/maint-tformat-with-z' into next

"log -z --pretty=tformat:..." does not terminate each record with NUL
and this is a beginning of an attempt to fix it.  It still is not right
but the patch does not make externally observable behaviour worse.

By Jan Krüger (1) and Junio C Hamano (1)
* jk/maint-tformat-with-z:
  log-tree: the previous one is still not quite right
  log-tree: use custom line terminator in line termination mode
Merge branch 'master' into next

* master:
  The eighth batch of topics graduated to 'master'
  git-svn: introduce SVN version comparison function
dumpstat work in progress
Merge branch 'cb/http-multi-curl-auth' into HEAD

By Clemens Buchacher (1) and Jeff King (1)
* cb/http-multi-curl-auth:
  fix http auth with multiple curl handles
  http auth fails with multiple curl handles
Merge branch 'jk/blame-tree' into HEAD

* jk/blame-tree:
  blame-tree wip
Merge branch 'jk/builtin-attr' into HEAD

* jk/builtin-attr:
  attr: drop C/C++ default extension mapping
  attr: map builtin userdiff drivers to well-known extensions
Merge branch 'jk/bundle-fetch' into HEAD

* jk/bundle-fetch:
  clone: give advice on how to resume a failed clone
  remote-curl: resume interrupted bundle transfers
  remote-curl: show progress for bundle downloads
  progress: allow pure-throughput progress meters
  remote-curl: try base $URL after $URL/info/refs
  remote-curl: auto-detect bundles when fetching refs
  remote-curl: free "discovery" object
  bundle: add is_bundle_buf helper
  transport: factor out bundle to ref list conversion
  remote-curl: use http callback for requesting refs
  http: add a public function for arbitrary-callback request
  http: refactor http_request function
  http: turn off curl signals
  t/lib-httpd: check for NO_CURL