Normally it doesn't matter if we show the pre-image or th post-image
for the common parts of a diff because they are the same.  If
white-space changes are ignored they can differ, though.  The
new text after applying the diff is more interesting in that case,
so show that instead of the old contents.

Note: GNU diff shows the pre-image.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Signed-off-by: Junio C Hamano <gitster@pobox.com>

The "--xhtml" option is supported only in highlight < 3.0. There is no option
to enforce (X)HTML output format compatible with both highlight < 3.0 and
highlight >= 3.0. However default output format is HTML so we don't need to
explicitly specify it.

Signed-off-by: Adam Tkac <atkac@redhat.com>
Helped-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* maint:
  rebase -i: clarify in-editor documentation of "exec"
  tests: sanitize more git environment variables
  fast-import: treat filemodify with empty tree as delete
  rebase: give a better error message for bogus branch
  rebase: use explicit "--" with checkout

Conflicts:
	t/t9300-fast-import.sh

The hints in the current "instruction sheet" template look like so:

 # Rebase 3f14246..a1d7e01 onto 3f14246
 #
 # Commands:
 #  p, pick = use commit
 #  r, reword = use commit, but edit the commit message
 #  e, edit = use commit, but stop for amending
 #  s, squash = use commit, but meld into previous commit
 #  f, fixup = like "squash", but discard this commit's log message
 #  x <cmd>, exec <cmd> = Run a shell command <cmd>, and stop if it fails
 #
 # If you remove a line here THAT COMMIT WILL BE LOST.
 # However, if you remove everything, the rebase will be aborted.
 #

This does not make it clear that the format of each line is

	<insn> <commit id> <explanatory text that will be printed>

but the reader will probably infer that from the automatically
generated pick examples above it.

What about the "exec" instruction?  By analogy, I might imagine that
the format of that line is "exec <command> <explanatory text>", and
the "x <cmd>" hint does not address that question (at first I read it
as taking an argument <cmd> that is the name of a shell).  Meanwhile,
the mention of <cmd> makes the hints harder to scan as a table.

So remove the <cmd> and add some words to remind the reader that
"exec" runs a command named by the rest of the line.  To make room, it
is left to the manpage to explain that that command is run using
$SHELL and that nonzero status from that command will pause the
rebase.

Wording from Junio.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

These variables should generally not be set in one's
environment, but they do get set by rebase, which means
doing an interactive rebase like:

  pick abcd1234 foo
  exec make test

will cause false negatives in the test suite.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* jn/fast-import-empty-tree-removal:
  fast-import: treat filemodify with empty tree as delete

Normal git processes do not allow one to build a tree with an empty
subtree entry without trying hard at it.  This is in keeping with the
general UI philosophy: git tracks content, not empty directories.

v1.7.3-rc0~75^2 (2010-06-30) changed that by making it easy to include
an empty subtree in fast-import's active commit:

	M 040000 4b825dc642cb6eb9a060e54bf8d69288fbee4904 subdir

One can trigger this by reading an empty tree (for example, the tree
corresponding to an empty root commit) and trying to move it to a
subtree.  It is better and more closely analogous to 'git read-tree
--prefix' to treat such commands as requests to remove the subtree.

Noticed-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

When you give a non-existent branch to git-rebase, it spits
out the usage. This can be confusing, since you may
understand the usage just fine, but simply have made a
mistake in the branch name.

Before:

  $ git rebase origin bogus
  Usage: git rebase ...

After:

  $ git rebase origin bogus
  fatal: no such branch: bogus
  Usage: git rebase ...

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

In the case of a ref/pathname conflict, checkout will
already do the right thing and checkout the ref. However,
for a non-existant ref, this has two advantages:

  1. If a file with that pathname exists, rebase will
     refresh the file from the index and then rebase the
     current branch instead of producing an error.

  2. If no such file exists, the error message using an
     explicit "--" is better:

       # before
       $ git rebase -i origin bogus
       error: pathspec 'bogus' did not match any file(s) known to git.
       Could not checkout bogus

       # after
       $ git rebase -i origin bogus
       fatal: invalid reference: bogus
       Could not checkout bogus

The problems seem to be trigger-able only through "git
rebase -i", as regular git-rebase checks the validity of the
branch parameter as a ref very early on. However, it doesn't
hurt to be defensive.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>