From @moritz

Created by moritz@faui2k3.org

This is a bug report for perl from moritz@​faui2k3.org,
generated with the help of perlbug 1.35 running under perl v5.8.8.

-----------------------------------------------------------------
On perl 5.8.8, the regex
/.*\z/
doesn't match strings ending with \n. Since .* can match an empty string as
well, _any_ string should match that regex.

This topic was discussed on permonks​: http​://www.perlmonks.org/?node_id=616538

Flags:
    category=core
    severity=low

Site configuration information for perl v5.8.8:

Configured by Debian Project at Wed Dec  6 23:17:41 UTC 2006.

Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=linux, osvers=2.6.18.3, archname=i486-linux-gnu-thread-multi
    uname='linux saens 2.6.18.3 #1 smp sat nov 25 13:39:52 est 2006 i686 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.8 -Darchlib=/usr/lib/perl/5.8 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.8.8 -Dsitearch=/usr/local/lib/perl/5.8.8 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dlibperl=libperl.so.5.8.8 -Dd_dosuid -des'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef useithreads=define usemultiplicity=define
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='4.1.2 20061115 (prerelease) (Debian 4.1.1-20)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=/lib/libc-2.3.6.so, so=so, useshrplib=true, libperl=libperl.so.5.8.8
    gnulibc_version='2.3.6'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    


@INC for perl v5.8.8:
    /etc/perl
    /usr/local/lib/perl/5.8.8
    /usr/local/share/perl/5.8.8
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.8
    /usr/share/perl/5.8
    /usr/local/lib/site_perl
    /usr/local/lib/perl/5.8.4
    /usr/local/share/perl/5.8.4
    .


Environment for perl v5.8.8:
    HOME=/home/moritz
    LANG=EN_US.UTF-8
    LANGUAGE=C
    LC_ALL=C
    LC_CTYPE=de_DE
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/bin:/sbin:/usr/bin:/usr/sbin:/home/moritz/bin:/usr/games:/usr/local/Eiffel54/studio/spec/linux-glibc2.1/bin:/usr/bin/X11:/usr/local/bin:
    PERL6LIB=/home/moritz/pugs/blib6/lib
    PERL_BADLANG (unset)
    SHELL=/bin/bash

From schubiger@gmail.com

On Mon, May 21, 2007 at 06​:50​:15AM -0700, moritz@​faui2k3.org (via RT) wrote​:

On perl 5.8.8, the regex
/.*\z/
doesn't match strings ending with \n. Since .* can match an empty string as
well, _any_ string should match that regex.

This topic was discussed on permonks​: http​://www.perlmonks.org/?node_id=616538

I can reproduce it with bleadperl #31251 (but I'm not sure
whether to consider it a bug or not). If it is, could it be
that is somehow related to regcomp.c?

  6580 case '.'​:
  6581 nextchar(pRExC_state);
  6582 if (RExC_flags & RXf_PMf_SINGLELINE)
  6583 ret = reg_node(pRExC_state, SANY);
  6584 else
  6585 ret = reg_node(pRExC_state, REG_ANY);
  6586 *flagp |= HASWIDTH|SIMPLE;
  6587 RExC_naughty++;
  6588 Set_Node_Length(ret, 1); /* MJD */
  6589 break;

The RT System itself - Status changed from 'new' to 'open'

From @demerphq

On 5/21/07, Steven Schubiger <schubiger@​gmail.com> wrote​:

On Mon, May 21, 2007 at 06​:50​:15AM -0700, moritz@​faui2k3.org (via RT) wrote​:

On perl 5.8.8, the regex
/.*\z/
doesn't match strings ending with \n. Since .* can match an empty string as
well, _any_ string should match that regex.

This topic was discussed on permonks​: http​://www.perlmonks.org/?node_id=616538

I can reproduce it with bleadperl #31251 (but I'm not sure
whether to consider it a bug or not). If it is, could it be
that is somehow related to regcomp.c?

6580 case '.'​:
6581 nextchar(pRExC_state);
6582 if (RExC_flags & RXf_PMf_SINGLELINE)
6583 ret = reg_node(pRExC_state, SANY);
6584 else
6585 ret = reg_node(pRExC_state, REG_ANY);
6586 *flagp |= HASWIDTH|SIMPLE;
6587 RExC_naughty++;
6588 Set_Node_Length(ret, 1); /* MJD */
6589 break;

nah, this is just the code for parsing the . (dot) construct. the
problem probably lies in the optimiser, wgich means study_chunk in
regcomp.c and various places in regexec.c

cheers.
yves

--
perl -Mre=debug -e "/just|another|perl|hacker/"

From @demerphq

On 5/21/07, via RT moritz @​ faui2k3. org <perlbug-followup@​perl.org> wrote​:

# New Ticket Created by moritz@​faui2k3.org
# Please include the string​: [perl #43015]
# in the subject line of all future correspondence about this issue.
# <URL​: http​://rt.perl.org/rt3/Ticket/Display.html?id=43015 >

This is a bug report for perl from moritz@​faui2k3.org,
generated with the help of perlbug 1.35 running under perl v5.8.8.

-----------------------------------------------------------------
On perl 5.8.8, the regex
/.*\z/
doesn't match strings ending with \n. Since .* can match an empty string as
well, _any_ string should match that regex.

This topic was discussed on permonks​: http​://www.perlmonks.org/?node_id=616538

Attached patch fixes this case, and also possibly as a sideffect
enables various optimisations that might not have been.

Once applied I believe that this bug can be closed.

Gotta say tho, the optimiser is a scary place.

cheers,
Yves

--
perl -Mre=debug -e "/just|another|perl|hacker/"

From @demerphq

Index: D:/dev/perl/ver/zoro/regcomp.c
===================================================================
--- D:/dev/perl/ver/zoro/regcomp.c	(revision 1874)
+++ D:/dev/perl/ver/zoro/regcomp.c	(revision 1875)
@@ -4121,7 +4121,6 @@
     char*  exp = SvPV((SV*)pattern, plen);
     char* xend = exp + plen;
     regnode *scan;
-    regnode *first;
     I32 flags;
     I32 minlen = 0;
     I32 sawplus = 0;
@@ -4145,7 +4144,7 @@
         PerlIO_printf(Perl_debug_log, "%sCompiling REx%s %s\n",
 		       PL_colors[4],PL_colors[5],s);
     });
-
+    
 redo_first_pass:
     RExC_precomp = exp;
     RExC_flags = pm_flags;
@@ -4381,18 +4380,20 @@
 	struct regnode_charclass_class ch_class; /* pointed to by data */
 	int stclass_flag;
 	I32 last_close = 0; /* pointed to by data */
-
-	first = scan;
+        regnode *first= scan;
+        regnode *first_next= regnext(first);
+	
 	/* Skip introductions and multiplicators >= 1. */
 	while ((OP(first) == OPEN && (sawopen = 1)) ||
 	       /* An OR of *one* alternative - should not happen now. */
-	    (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
+	    (OP(first) == BRANCH && OP(first_next) != BRANCH) ||
 	    /* for now we can't handle lookbehind IFMATCH*/
 	    (OP(first) == IFMATCH && !first->flags) || 
 	    (OP(first) == PLUS) ||
 	    (OP(first) == MINMOD) ||
 	       /* An {n,m} with n>0 */
-	    (PL_regkind[OP(first)] == CURLY && ARG1(first) > 0) ) 
+	    (PL_regkind[OP(first)] == CURLY && ARG1(first) > 0) ||
+	    (OP(first) == NOTHING && PL_regkind[OP(first_next)] != END )) 
 	{
 	        
 		if (OP(first) == PLUS)
@@ -4404,6 +4405,7 @@
 		    first += EXTRA_STEP_2ARGS;
 		} else  /* XXX possible optimisation for /(?=)/  */
 		    first = NEXTOPER(first);
+		first_next= regnext(first);
 	}
 
 	/* Starting-point info. */
Index: D:/dev/perl/ver/zoro/t/op/re_tests
===================================================================
--- D:/dev/perl/ver/zoro/t/op/re_tests	(revision 1874)
+++ D:/dev/perl/ver/zoro/t/op/re_tests	(revision 1875)
@@ -1324,3 +1324,5 @@
 foo(\h)bar	foo\tbar	y	$1	\t
 (\H)(\h)	foo\tbar	y	$1-$2	o-\t
 (\h)(\H)	foo\tbar	y	$1-$2	\t-b
+
+.*\z	foo\n	y	-	-
Index: D:/dev/perl/ver/zoro/regexec.c
===================================================================
--- D:/dev/perl/ver/zoro/regexec.c	(revision 1874)
+++ D:/dev/perl/ver/zoro/regexec.c	(revision 1875)
@@ -1845,7 +1845,7 @@
 		    if (regtry(&reginfo, &s))
 			goto got_it;
 		  after_try:
-		    if (s >= end)
+		    if (s > end)
 			goto phooey;
 		    if (prog->extflags & RXf_USE_INTUIT) {
 			s = re_intuit_start(prog, sv, s + 1, strend, flags, NULL);

@rgs - Status changed from 'open' to 'resolved'

From @rgs

On 28/05/07, demerphq <demerphq@​gmail.com> wrote​:

Attached patch fixes this case, and also possibly as a sideffect
enables various optimisations that might not have been.

Once applied I believe that this bug can be closed.

Gotta say tho, the optimiser is a scary place.

Hic sunt leones. Thanks, applied as #31303.