Re: problem with texi2dvi from texinfo 6.1

[Gavin Smith]

On 23 February 2016 at 23:15, Vincent Belaïche
<address@hidden> wrote:
>
> OK, I got it. The problem is in function filter_files. Unfortunately
> when we made the changes to solve the missing \openout in log problem,
> we did not make any tests with not any new xref files after the first
> run. When this happens (ie variable xref_files_new empty) the function
> filter_files crashes and exits the script. I have not really understood
> the details why, but the attached patch fixes that.
>
> It would be good to understand exactly what is happening with the bug
> because there are similar pieces of coding for instance in
>
> if test -n "$COMSPEC$ComSpec" \
>    && MSYSTEM=$OSTYPE uname | $EGREP -iv 'cygwin|msys' >/dev/null; then
>
> which was also changed at the same time.

Thanks for sending the patch, can you send a ChangeLog entry as well
and I'll install it?

The conditionals with "if" should be OK.

I think I've seen a bug like this before. The function has only one line:

 test -n "$xref_files_new" && echo "$xref_files_new" |
  # Filter existing files matching the criterion.
  #
  while read file; do
    $1 "$file"
  done |
  sort |
  # Some files are opened several times, e.g., listings.sty's *.vrb.
  uniq

This would not normally cause an exit with set -e. From (bash)The Set Builtin:

  `-e'
          Exit immediately if a pipeline (*note Pipelines::), which may
          consist of a single simple command (*note Simple Commands::),
          a subshell command enclosed in parentheses (*note Command
          Grouping::), or one of the commands executed as part of a
          command list enclosed by braces (*note Command Grouping::)
          returns a non-zero status.  The shell does not exit if the
          command that fails is part of the command list immediately
          following a `while' or `until' keyword, part of the test in
          an `if' statement, part of any command executed in a `&&' or
          `||' list except the command following the final `&&' or `||',
          any command in a pipeline but the last, or if the command's
          return status is being inverted with `!'.  A trap on `ERR',
          if set, is executed before the shell exits.

However, it's hidden inside a function, so the exception for && and ||
doesn't apply, apparently.

Any use of && for a conditional is suspect.