Re: [PATCH] fix hang in grep -F for empty string search

[Jim Meyering]

Paolo Bonzini wrote:
...
> Subject: [PATCH 5/5] tests: improve empty test
>
> * tests/empty: Add more tests, note expected failure.
> ---
>  tests/empty |   42 +++++++++++++++++++++++++++++++++++++++++-
>  1 files changed, 41 insertions(+), 1 deletions(-)
>
> diff --git a/tests/empty b/tests/empty
> index cd0d3fa..9e8f335 100755
> --- a/tests/empty
> +++ b/tests/empty
> @@ -16,7 +16,7 @@ require_timeout_
>  failures=0
>
>  for locale in C en_US.UTF-8; do
> -    for options in '-E' '-E -w' '-F -x' '-G -w -x'; do
> +    for options in '-E' '-F'; do
>
>       # should return 0 found a match
>       echo "" | LC_ALL=$locale timeout 10s grep $options -e ''
> @@ -38,6 +38,46 @@ for locale in C en_US.UTF-8; do
>               echo "Status: Wrong status code, test \#3 failed ($options 
> $locale)"
>               failures=1
>       fi

...
> +    # -F -w omitted because it fails test #6, will be revisited after 2.6
> +    # stabilizes.

I'm sure this bug you're documenting here will be fixed soon,
[I've confirmed it's present all the way back to at least grep-2.0]
but it'd be nice to make it a little clearer.  You could say that

  echo | src/grep -Fw '' exits with status 1 (no match), while without -F,
  echo | src/grep -w ''  works fine and prints the empty line.

I was tempted to add a separate test, since it's locale-independent,
but it's probably not worth it.

...
> +    for options in '-E -w' '-E -x' '-E -w -x' '-F -x' '-F -w -x'; do
> +
> +     # should return 0 found a match
> +     echo "" | LC_ALL=$locale timeout 10s grep $options -e ''
> +     if test $? -ne 0 ; then
> +             echo "Status: Wrong status code, test \#6 failed ($options 
> $locale)"
> +             failures=1
> +     fi

Thanks for the additions!