Re: grep-2.6.2 -Ff hangs on files with empty lines

[Jim Meyering]

Jim Meyering wrote:
> Allan McRae wrote:
>> On 31/03/10 16:21, Jim Meyering wrote:
>>> Allan McRae wrote:
>>>> Grep-2.6.2 will hang on "grep -Ff foo bar" if foo contains an empty
>>>> line.  The bug is new to 2.6.2.
>>>
>>> Thanks for the report.
>>> However, so far, I am unable to reproduce that.
>>>
>>> Please provide more details:
>>>    - type of CPU and OS you are using
>>
>> I am running Arch Linux and get the issue on both i686 and x86_64.
>> Grep is configured with:
>> ./configure --prefix=/usr --bindir=/bin --without-included-regex
>>
>>>    - the contents of your "foo" and "bar" files
>>
>> I replicate using your example:
>>
>> printf 'a\n\nb\n' > foo
>> seq 10 > bar
>> grep -Ff foo bar
>
>
> I don't have an Arch Linux system handy, so
> I rebuilt --without-included-regex on F11, F12, F13-alpha, rawhide,
> and a couple of debian and even a Centos 5.4 system.
> On all of them, I saw this (and no hang):
>
>     $ printf 'a\n\nb\n' > foo; seq 10 > bar; src/grep -Ff foo bar
>     1
>     2
>     3
>     4
>     5
>     6
>     7
>     8
>     9
>     10
>
> I suspect something about your system.  The compiler?
> Did grep's "make check" pass?
>
> Please run it under gdb and send a backtrace showing where it's hanging.

No need.
Paolo realized that all of my tests were probably being
run with LC_ALL=C.  D'oh!

This reproduces it even for me:

  echo a | LC_ALL=en_US.UTF-8 src/grep -F ''