bug#25655: grep-2.28 is broken with multiple -e patterns

[Lars Wendler]

Hi,

we got a bug report a Gentoo [1] that grep-2.28 is broken when
searching for multiple patterns with -e:

grep-2.27:

  % echo ".tar" | grep -e "\.tar"; echo $?           
  .tar
  0

  % echo ".tar" | grep -e "\.tar" -e "\.tbz"; echo $?
  .tar
  0


grep-2.28:

   % echo ".tar" | grep -e "\.tar"; echo $?           
   .tar
   0

   % echo ".tar" | grep -e "\.tar" -e "\.tbz"; echo $?
   1


But this seems to be not the only issue:


echo "atbz" | grep -e "\.tar" -e ".tbz"

is matching "atbz"

echo ".tbz" | grep -e "\.tar" -e ".tbz"

matches ".tbz"

but

echo ".tar" | grep -e "\.tar" -e "tar"

only matches "ta".


We've identified commit 290ca116c9172d97b2b026951fac722d3bd3ced9 as the
one that introduced this regression

Kind regards
Lars

[1] https://bugs.gentoo.org/608644

-- 
Lars Wendler
Gentoo package maintainer
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