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

Thomas Rast [off-list ref] writes:

quoted

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

...
IIRC this particular usage was designed to suppress warnings about unset
variables.

This is an old-timer's habit to work around buggy implementations of
Bourne shells where they failed to expand "$@" to nothing when there
is no parameters, feeding a single empty argument to the command.
By explicitly writing ${1+...}, the construct makes sure that when
we have no parameter (i.e. $1 is unset) we do not even look at "$@".

It is equivalent to "$@" in correctly implemented shells.