Arch Linux

What happens if you run that command manually? Note there is an extra space in the file name above.

seems to be a bug in grep.
"grep -vxFf foo bar" should write all lines of bar to stdout, which do not occur in foo.
if the first line of foo is empty, the new version of grep hangs. the old version didn't show this behavior.
that's the reason why pm-suspend fails ....

infact this bug occurs in a more general setting:
"grep -Ff foo bar" will hang if foo contains an empty line.

should i file this upstream? where? im not familiar with grep development..

I have sent a message to the bug-grep mailing list

I just sent an email with the following info to the list, just for reference:
---------------------
I can trigger it with LANG='de_DE.utf8' but it doesn't happen with LC_ALL=C.

The blocking occurs in kwsearch.c (relevant commit: 6d952beebdac1d8f31ba20abb12a756a9877e50d ), if I revert that specific patch the blocking is gone but now the output is incorrect, so this doesn't seem to seems to be source of the error.

$ src/grep -Ff <(printf '\na') <(printf 'a\nb')
a

$ LC_ALL=C src/grep -Ff <(printf '\na') <(printf 'a\nb')
a
b
---------------------

Regards,

Raphael Kimmig

Seems I was a bit slow :-) Already fixed:

Paolo Bonzini wrote:
> I just posted a patch to fix this and add it to the testsuite.
>
>
> Paolo

Yes - I have started updating the package. Will upload when I get home.

A workaround to get pm-suspend working until a fixed grep is available which involves editing /usr/lib/pm-utils/functions to leave out the leading blank line has worked for me and may be helpful to others:
@@ -219,9 +219,9 @@
remove_parameters() {
local p
if [ "$1" = "all" ]; then
- echo '' > "$PARAMETERS.new"
+ :>"$PARAMETERS.new"
else
- echo '' > "$PARAMETERS.rm"
+ :>"$PARAMETERS.rm"
for p in "$@"; do
echo "$p" >> "$PARAMETERS.rm"
done

the new version of grep from testing and grep-2.5.4 still behave strangly, if the search pattern file contains an empty line.
grep -Ff foo bar will then just match every line of bar.
i guess that's not intended.

That is supposed to be fixed by http://git.savannah.gnu.org/cgit/grep.git/commit/?id=5fa8c7c9 . I have sent a query upstream.

I can confirm that Joel Hough's patch works. Thanks!

> grep -Ff foo bar will then just match every line of bar.

Confirmed upstream that this is intended. pm-utils needs fix. File a separate bug report for that.