From 71edc89419f11505f2cdaba9b13be65582d7f011 Mon Sep 17 00:00:00 2001
From: Father Chrysostomos <sprout@cpan.org>
Date: Sun, 5 Jun 2011 22:37:54 -0700
Subject: [perl #92258] <$fh> hangs on a glob copy
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Opening a file handle to \$glob causes assertion failures
(under debugging) or hangs or other erratic behaviour without
debugging. This might even crash in some cases.

It never really worked properly, but it didn’t start hanging
apparently until 5.12.2 and 5.14.0.
---
 ext/PerlIO-scalar/scalar.xs | 13 ++++++++++---
 t/io/perlio.t               |  8 +++++++-
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/ext/PerlIO-scalar/scalar.xs b/ext/PerlIO-scalar/scalar.xs
index de9873829c..e0f75acf1a 100644
--- a/ext/PerlIO-scalar/scalar.xs
+++ b/ext/PerlIO-scalar/scalar.xs
@@ -240,9 +240,13 @@ PerlIOScalar_get_cnt(pTHX_ PerlIO * f)
 {
     if (PerlIOBase(f)->flags & PERLIO_F_CANREAD) {
 	PerlIOScalar *s = PerlIOSelf(f, PerlIOScalar);
+	STRLEN len;
 	SvGETMAGIC(s->var);
-	if (SvCUR(s->var) > (STRLEN) s->posn)
-	    return SvCUR(s->var) - (STRLEN)s->posn;
+	if (isGV_with_GP(s->var))
+	    (void)SvPV(s->var,len);
+	else len = SvCUR(s->var);
+	if (len > (STRLEN) s->posn)
+	    return len - (STRLEN)s->posn;
 	else
 	    return 0;
     }
@@ -264,9 +268,12 @@ void
 PerlIOScalar_set_ptrcnt(pTHX_ PerlIO * f, STDCHAR * ptr, SSize_t cnt)
 {
     PerlIOScalar *s = PerlIOSelf(f, PerlIOScalar);
+    STRLEN len;
     PERL_UNUSED_ARG(ptr);
     SvGETMAGIC(s->var);
-    s->posn = SvCUR(s->var) - cnt;
+    if (isGV_with_GP(s->var)) (void)SvPV(s->var,len);
+    else len = SvCUR(s->var);
+    s->posn = len - cnt;
 }
 
 PerlIO *
diff --git a/t/io/perlio.t b/t/io/perlio.t
index 1a330f4367..a65b0d3eb9 100644
--- a/t/io/perlio.t
+++ b/t/io/perlio.t
@@ -6,7 +6,7 @@ BEGIN {
 	skip_all_without_perlio();
 }
 
-plan tests => 42;
+plan tests => 44;
 
 use_ok('PerlIO');
 
@@ -191,6 +191,12 @@ close ($perlio);
 close ($no_perlio);
 }
 
+{ # [perl #92258]
+    open my $fh, "<", \(my $f = *f);
+    is join("", <$fh>), '*main::f', 'reading from a glob copy';
+    is ref \$f, 'GLOB', 'the glob copy is unaffected';
+}
+
 }
 
 
-- 
cgit v1.2.1