[perl #25158] [PATCH] Text::Balanced _match_bracketed, incorrect handling defined

# New Ticket Created by  David Manura 
# Please include the string:  [perl #25158]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=25158 >


This is a bug report for perl from davidm.perl@math2.org,
generated with the help of perlbug 1.34 running under perl v5.8.3.


-----------------------------------------------------------------
[Please enter your report here]

The following patch corrects a bug in Text::Balanced, in calling _match_bracketed.
The problem was that _match_bracketed could succeed but still evaluate to 0
in scalar context when there is no more input because _match_bracketed returns
a list whose last element is the length of the remaining unmatched text.
Therefore, the "|| do" statement would incorrectly execute the failure code
when no text remains.  "defined"s have been added to correctly handle the return values.

Also included is a new test case that fails under the original code.

==================
diff -r -u perl-5.8.3/lib/Text/Balanced/t/extqlk.t perl-5.8.3-patched/lib/Text/Balanced/t/extqlk.t
--- perl-5.8.3/lib/Text/Balanced/t/extqlk.t	2001-11-19 22:59:36.000000000 -0500
+++ perl-5.8.3-patched/lib/Text/Balanced/t/extqlk.t	2004-01-20 01:39:42.000000000 -0500
@@ -14,7 +14,7 @@
  # Change 1..1 below to 1..last_test_to_print .
  # (It may become useful if the test is moved to ./t subdirectory.)

-BEGIN { $| = 1; print "1..89\n"; }
+BEGIN { $| = 1; print "1..90\n"; }
  END {print "not ok 1\n" unless $loaded;}
  use Text::Balanced qw ( extract_quotelike );
  $loaded = 1;
@@ -62,6 +62,13 @@
  	print "\n";
  }

+# fails in Text::Balanced 1.95
+$_ = qq(s{}{});
+my @z = extract_quotelike();
+print "not " if $z[0] eq '';
+print "ok ", $count++;
+print "\n";
+
  __DATA__

  # USING: extract_quotelike($str);
diff -r -u perl-5.8.3/lib/Text/Balanced.pm perl-5.8.3-patched/lib/Text/Balanced.pm
--- perl-5.8.3/lib/Text/Balanced.pm	2003-07-04 10:33:00.000000000 -0400
+++ perl-5.8.3-patched/lib/Text/Balanced.pm	2004-01-20 01:41:18.000000000 -0500
@@ -791,7 +791,7 @@
  	if ($ldel1 =~ /[[(<{]/)
  	{
  		$rdel1 =~ tr/[({</])}>/;
-		_match_bracketed($textref,"",$ldel1,"","",$rdel1)
+		defined(_match_bracketed($textref,"",$ldel1,"","",$rdel1))
  		|| do { pos $$textref = $startpos; return };
  	}
  	else
@@ -826,7 +826,7 @@
  		if ($ldel2 =~ /[[(<{]/)
  		{
  			pos($$textref)--;	# OVERCOME BROKEN LOOKAHEAD
-			_match_bracketed($textref,"",$ldel2,"","",$rdel2)
+			defined(_match_bracketed($textref,"",$ldel2,"","",$rdel2))
  			|| do { pos $$textref = $startpos; return };
  		}
  		else

==================

[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
     category=library
     severity=medium
---
Site configuration information for perl v5.8.3:

Configured by dmanura at Mon Jan 19 21:39:59 2004.

Summary of my perl5 (revision 5 version 8 subversion 3) configuration:
   Platform:
     osname=MSWin32, osvers=4.0, archname=MSWin32-x86-multi-thread
     uname=''
     config_args='undef'
     hint=recommended, useposix=true, d_sigaction=undef
     usethreads=undef 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='cl', ccflags ='-nologo -Gf -W3 -MD -DNDEBUG -O1 -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT  -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX',
     optimize='-MD -DNDEBUG -O1',
     cppflags='-DWIN32'
     ccversion='', gccversion='', gccosandvers=''
     intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
     d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
     ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='__int64', lseeksize=8
     alignbytes=8, prototype=define
   Linker and Libraries:
     ld='link', ldflags ='-nologo -nodefaultlib -release  -libpath:"c:\perl\lib\CORE"  -machine:x86'
     libpth=D:\lib\mvs-6.0\VC98\lib
     libs=  oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib  comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib  netapi32.lib uuid.lib wsock32.lib mpr.lib winmm.lib  version.lib odbc32.lib odbccp32.lib msvcrt.lib
     perllibs=  oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib  comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib  netapi32.lib uuid.lib wsock32.lib mpr.lib winmm.lib  version.lib odbc32.lib odbccp32.lib msvcrt.lib
     libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl58.lib
     gnulibc_version='undef'
   Dynamic Linking:
     dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
     cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -release  -libpath:"c:\perl\lib\CORE"  -machine:x86'

Locally applied patches:


---
@INC for perl v5.8.3:
     d:/testing/perl-5.8.3/lib
     .

---
Environment for perl v5.8.3:
     HOME=
     LANG (unset)
     LANGUAGE (unset)
     LD_LIBRARY_PATH (unset)
     LOGDIR (unset)
     PATH=
     PERLDB_OPTS=RemotePort=127.0.0.1:2000
     PERL_BADLANG (unset)
     SHELL (unset)

• [perl #25158] [PATCH] Text::Balanced _match_bracketed, incorrect handling defined by David Manura