Date: Sat, 07 May 2016 00:58:43 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 209352] Bug in usr.bin/sed Message-ID: <bug-209352-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D209352 Bug ID: 209352 Summary: Bug in usr.bin/sed Product: Base System Version: 11.0-CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: freebsd-bugs@FreeBSD.org Reporter: pfg@FreeBSD.org This was noted from the openbsd-bugs list : (Reply from Tim Chase 2016-04-24)... Can be simplified to the test-case $ echo a,a,a,a,a | sed -r 's/\<.,/X&/g' Xa,a,Xa,a,a $ echo a,a,a,a,a | gsed -r 's/\<.,/X&/g' Xa,Xa,Xa,Xa,a It appears the determination of "\<" can get thrown off when the character preceding it is part of a replacement. _____ I have reproduced it with the sed in FreeBSD _____ There is a solution candidate in openbsd-tech, but the patch doesn't apply directly: >From Martijn van Duren - 2016-05-04) For those interested: The problem comes from the fact that the string pointer increments to the end of the previous match and is then called with the REG_NOTBOL. The REG_NOTBOL combined with a match at the begin of the string causes our regex library to treat the word as not begin of word. The TRE implementation does the reverse and treats this case as if it always is begin of word. This causes a similar bug under MacOS: $ echo 'foo foofoo' | sed -E 's/\<foo/bar/g' bar barbar I've solved this problem by converting sed to use REG_STARTEND more explicitly. Although this isn't a POSIX specified flag, it is already used by sed and shouldn't be a problem. --=20 You are receiving this mail because: You are the assignee for the bug.=
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