From: Stephen McCamant <smcc@mit.edu>
Date: Thu, 2 Jan 2003 18:08:23 +0000 (-0500)
Subject: Re: [perl #19566] Perl 5.8.0 segfault
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=79628082eace9d4fea95d94e0f5a65aa9c61455c;p=p5sagit%2Fp5-mst-13.2.git

Re: [perl #19566] Perl 5.8.0 segfault
Message-ID: <15892.50791.692636.982873@syllepsis.MIT.EDU>
Plus a test by Jarkko
Integrated from changes 18444 and 18446 from maint-5.8

p4raw-id: //depot/perl@18485
p4raw-branched: from //depot/maint-5.8/perl@18484 'branch in'
	t/op/readline.t
p4raw-integrated: from //depot/maint-5.8/perl@18446 'merge in' MANIFEST
	(@18436..)
p4raw-integrated: from //depot/maint-5.8/perl@18444 'merge in' pp_hot.c
	(@18173..)
---

diff --git a/MANIFEST b/MANIFEST
index e8c8e66..9ebb6a6 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -2601,6 +2601,7 @@ t/op/quotemeta.t		See if quotemeta works
 t/op/rand.t			See if rand works
 t/op/range.t			See if .. works
 t/op/read.t			See if read() works
+t/op/readline.t			See if <> / readline work
 t/op/readdir.t			See if readdir() works
 t/op/recurse.t			See if deep recursion works
 t/op/ref.t			See if refs and objects work
diff --git a/pp_hot.c b/pp_hot.c
index 24d26d7..461c666 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1466,6 +1466,8 @@ Perl_do_readline(pTHX)
 		report_evil_fh(PL_last_in_gv, io, PL_op->op_type);
 	}
 	if (gimme == G_SCALAR) {
+	    /* undef TARG, and push that undefined value */
+	    SV_CHECK_THINKFIRST_COW_DROP(TARG);
 	    (void)SvOK_off(TARG);
 	    PUSHTARG;
 	}
@@ -1527,6 +1529,7 @@ Perl_do_readline(pTHX)
 		}
 	    }
 	    if (gimme == G_SCALAR) {
+		SV_CHECK_THINKFIRST_COW_DROP(TARG);
 		(void)SvOK_off(TARG);
 		SPAGAIN;
 		PUSHTARG;
diff --git a/t/op/readline.t b/t/op/readline.t
new file mode 100644
index 0000000..ae04312
--- /dev/null
+++ b/t/op/readline.t
@@ -0,0 +1,13 @@
+#!./perl
+
+BEGIN {
+    chdir 't';
+    @INC = '../lib';
+    require './test.pl';
+}
+
+plan tests => 1;
+
+eval { for (\2) { $_ = <FH> } };
+like($@, 'Modification of a read-only value attempted', '[perl #19566]');
+