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[perl #68590] %^H not lexical enough

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August 17, 2009 07:08
[perl #68590] %^H not lexical enough
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# New Ticket Created by  Zefram 
# Please include the string:  [perl #68590]
# in the subject line of all future correspondence about this issue. 
# <URL: >

This is a bug report for perl from,
generated with the help of perlbug 1.36 running under perl 5.10.0.

[Please enter your report here]

perlvar(1) says:

#      %^H     The %^H hash provides the same scoping semantic as $^H.  This
#              makes it useful for implementation of lexically scoped pragmas.
#              See perlpragma.

The first sentence of that description is not true.  Specifically, the
scoping semantics match within a single file, but when require/use-ing
a new file, $^H gets reset to its initial value but %^H inherits the
value from the outer file.  Demonstration:

$ cat
package x0;
printf "0x%08x %s\n", $^H, $^H{foo};
$ perl -e 'BEGIN { $^H |= 1; $^H{foo} = "zzz"; printf "0x%08x %s\n", $^H, $^H{foo}; } use x0; BEGIN { printf "0x%08x %s\n", $^H, $^H{foo}; }'
0x00020101 zzz
0x00000100 zzz
0x00020101 zzz

Observe that the 0x1 bit of $^H has been reset, as seen in, but
$^H{foo} retains its value.

This occurs both in 5.10.0 and 5.10.1-RC1, despite this interesting diff
between them in pp_require:

@@ -3466,6 +3535,11 @@
     PL_hints = 0;
+    if (PL_compiling.cop_hints_hash) {
+	Perl_refcounted_he_free(aTHX_ PL_compiling.cop_hints_hash);
+	PL_compiling.cop_hints_hash = NULL;
+    }
     if (PL_dowarn & G_WARN_ALL_ON)
         PL_compiling.cop_warnings = pWARN_ALL ;

[Please do not change anything below this line]
Site configuration information for perl 5.10.0:

Configured by Debian Project at Thu Jan  1 12:43:38 UTC 2009.

Summary of my perl5 (revision 5 version 10 subversion 0) configuration:
    osname=linux, osvers=2.6.26-1-686, archname=i486-linux-gnu-thread-multi
    uname='linux rebekka 2.6.26-1-686 #1 smp mon dec 15 18:15:07 utc 2008 i686 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.10 -Darchlib=/usr/lib/perl/5.10 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.10.0 -Dsitearch=/usr/local/lib/perl/5.10.0 -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 -Ud_ualarm -Uusesfio -Uusenm -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dd_dosuid -des'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=undef, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -g',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='4.3.2', 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 /usr/lib64
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=/lib/, so=so, useshrplib=true,
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -g -L/usr/local/lib'

Locally applied patches:

@INC for perl 5.10.0:

Environment for perl 5.10.0:
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PERL_BADLANG (unset)

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