Re: syntax error in git-rebase while running t34* tests

[Jeff King <peff@peff.net>]

On Tue, May 10, 2016 at 01:53:56PM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > I think it is clear why it works. If $strategy_opts is empty, then the
> > code we generate looks like:
> >
> >   for strategy_opt in
> >   do
> >           ...
> >   done
> 
> Ah, of course.  Thanks.

Here it is as a patch and commit message.

-- >8 --
Subject: [PATCH] rebase--interactive: avoid empty list in shell for-loop

The $strategy_opts variable contains a space-separated list
of strategy options, each individually shell-quoted. To loop
over each, we "unwrap" them by doing an eval like:

  eval '
    for opt in '"$strategy_opts"'
    do
       ...
    done
  '

Note the quoting that means we expand $strategy_opts inline
in the code to be evaluated (which is the right thing
because we want the IFS-split and de-quoting). If the
variable is empty, however, we ask the shell to eval the
following code:

  for opt in
  do
     ...
  done

without anything between "in" and "do".  Most modern shells
are happy to treat that like a noop, but reportedly ksh88 on
AIX considers it a syntax error. So let's catch the case
that the variable is empty and skip the eval altogether
(since we know the loop would be a noop anyway).

Reported-by: Armin Kunaschik <megabreit@googlemail.com>
Signed-off-by: Jeff King <peff@peff.net>
---
 git-rebase--interactive.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 9ea3075..1c6dfb6 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -82,6 +82,7 @@ rewritten_pending="$state_dir"/rewritten-pending
 cr=$(printf "\015")
 
 strategy_args=${strategy:+--strategy=$strategy}
+test -n "$strategy_opts" &&
 eval '
 	for strategy_opt in '"$strategy_opts"'
 	do
-- 
2.8.2.660.ge43c418