[PATCH] Documentation/githooks: Explain pre-rebase parameters

From: "W. Trevor King" <redacted>

Descriptions borrowed from templates/hooks--pre-rebase.sample.

Signed-off-by: W. Trevor King <redacted>
---
I'm not 100% convinced about this, because the git-rebase.sh uses:

  "$GIT_DIR/hooks/pre-rebase" ${1+"$@"}

I haven't been able to find documentation for the ${1+"$@"} syntax.
Is it in POSIX?  It's not in the Bash manual:

  $ man bash | grep '\${.*[+]'
              (${BASH_SOURCE[$i+1]})  where  ${FUNCNAME[$i]}  was  called  (or
              ${BASH_SOURCE[$i+1]}.
              ${BASH_SOURCE[$i+1]}  at  line  number  ${BASH_LINENO[$i]}.  The
       ${parameter:+word}

In my local tests, it seems equivalent to "$@".

Also, it appears that the `git-rebase--*.sh` handlers don't use the
pre-rebase hook.  Is this intentional?

Cheers,
Trevor

 Documentation/githooks.txt | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
index b9003fe..bc837c6 100644
--- a/Documentation/githooks.txt
+++ b/Documentation/githooks.txt

@@ -140,9 +140,10 @@ the outcome of 'git commit'.
 pre-rebase
 ~~~~~~~~~~
 
-This hook is called by 'git rebase' and can be used to prevent a branch
-from getting rebased.
-
+This hook is called by 'git rebase' and can be used to prevent a
+branch from getting rebased.  The hook takes two parameters: the
+upstream the series was forked from and the branch being rebased.  The
+second parameter will be empty when rebasing the current branch.
 
 post-checkout
 ~~~~~~~~~~~~~

-- 
1.8.1.336.g94702dd