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Postings from April 2003
On Wed, Apr 09, 2003 at 06:03:48PM -0000, Jarkko Hietaniemi wrote:
> At some point after 5.8.0 the following code
>
> use strict;
> open(local $f, '<', '/might/exist/might/not');
> my @rows = <$f>;
>
> changed behaviour from
>
> Global symbol "$f" requires explicit package name at o.t line 2.
> Global symbol "$f" requires explicit package name at o.t line 3.
> Execution of o.t aborted due to compilation errors.
>
> to
>
> zsh: 386540 segmentation fault (core dumped) ./perl -Ilib o.t
a simpler example:
$ perl -e 'BEGIN { $^H |= 0x400 } @b = <$f>'
Segmentation fault
The SEGV happens in Perl_newASSIGNOP op.c:3089 because SvCUR() tries
to dereference a NULL 'gv' pointer.
That 'gv' is NULL because change #17942 removed PL_nullstash,
from which the return value of gv_fetchpv had to be fetched when
HINT_STRICT_VARS was set.
see gv.c:722,734,759 and the gv.c hunk in change #17942
(it should be now line 764)
I don't think that gv_fetchpv returning NULL when its 'add' argument
is non-zero is exactly right - and I failed to see what was so
wrong with PL_nullstash.
Below I simply test for a non-null 'gv' - but, again, what
harm was PL_nullstash doing ?
Regards
Adi
------------------------------------------------------------------------
--- /arc/bleadperl/op.c 2003-04-08 23:56:49.000000000 +0300
+++ bleadperl/op.c 2003-04-10 04:00:38.000000000 +0300
@@ -3086,7 +3086,8 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *le
if (PL_opargs[curop->op_type] & OA_DANGEROUS) {
if (curop->op_type == OP_GV) {
GV *gv = cGVOPx_gv(curop);
- if (gv == PL_defgv || (int)SvCUR(gv) == PL_generation)
+ if (!gv || gv == PL_defgv ||
+ (int)SvCUR(gv) == PL_generation)
break;
SvCUR(gv) = PL_generation;
}
--- /arc/bleadperl/t/lib/strict/vars 2002-01-10 17:53:14.000000000 +0200
+++ bleadperl/t/lib/strict/vars 2003-04-10 04:28:40.000000000 +0300
@@ -421,3 +421,12 @@
EXPECT
Global symbol "@i_like_crackers" requires explicit package name at - line 7.
Execution of - aborted due to compilation errors.
+########
+
+# [perl #21914] New bug > 5.8.0. Uses to dump core.
+use strict 'vars';
+@k = <$k>;
+EXPECT
+Global symbol "@k" requires explicit package name at - line 4.
+Global symbol "$k" requires explicit package name at - line 4.
+Execution of - aborted due to compilation errors.
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