From: Tassilo von Parseval <tassilo.parseval@post.rwth-aachen.de>
Date: Wed, 20 Jul 2005 10:43:11 +0000 (+0200)
Subject: lvalue-subs returning elements of tied hashes/arrays
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=f9bc45eff51a0e2fac1537ecee1124be910c832e;p=p5sagit%2Fp5-mst-13.2.git

lvalue-subs returning elements of tied hashes/arrays
Message-id: <20050720084311.GA20332@ethan>

p4raw-id: //depot/perl@25194
---

diff --git a/pp_hot.c b/pp_hot.c
index 1e3d5ea..8298026 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -2441,7 +2441,10 @@ PP(pp_leavesublv)
 	    MARK = newsp + 1;
 	    EXTEND_MORTAL(1);
 	    if (MARK == SP) {
-		if (SvFLAGS(TOPs) & (SVs_TEMP | SVs_PADTMP | SVf_READONLY)) {
+		/* Temporaries are bad unless they happen to be elements
+		 * of a tied hash or array */
+		if (SvFLAGS(TOPs) & (SVs_TEMP | SVs_PADTMP | SVf_READONLY) &&
+		    !(SvRMAGICAL(TOPs) && mg_find(TOPs, PERL_MAGIC_tiedelem))) {
 		    LEAVE;
 		    cxstack_ix--;
 		    POPSUB(cx,sv);
diff --git a/t/op/sub_lval.t b/t/op/sub_lval.t
index c161b4b..953a1e0 100755
--- a/t/op/sub_lval.t
+++ b/t/op/sub_lval.t
@@ -1,4 +1,4 @@
-print "1..68\n";
+print "1..72\n";
 
 BEGIN {
     chdir 't' if -d 't';
@@ -530,8 +530,51 @@ sub lval2 : lvalue { $ary[1]; }
 print "not " unless join(':', @ary) eq "1:2:6";
 print "ok 64\n";
 
+# check that an element of a tied hash/array can be assigned to via lvalueness
+
+package Tie_Hash;
+
+our ($key, $val);
+sub TIEHASH { bless \my $v => __PACKAGE__ }
+sub STORE   { ($key, $val) = @_[1,2] }
+
+package main;
+sub lval_tie_hash : lvalue {
+    tie my %t => 'Tie_Hash';
+    $t{key};
+}
+
+eval { lval_tie_hash() = "value"; };
+
+print "# element of tied hash: $@\nnot " if $@;
+print "ok 65\n";
+
+print "not " if "$Tie_Hash::key-$Tie_Hash::val" ne "key-value";
+print "ok 66\n";
+
+
+package Tie_Array;
+
+our @val;
+sub TIEARRAY { bless \my $v => __PACKAGE__ }
+sub STORE   { $val[ $_[1] ] = $_[2] }
+
+package main;
+sub lval_tie_array : lvalue {
+    tie my @t => 'Tie_Array';
+    $t[0];
+}
+
+eval { lval_tie_array() = "value"; };
+
+print "# element of tied array: $@\nnot " if $@;
+print "ok 67\n";
+
+print "not " if $Tie_Array::val[0] ne "value";
+print "ok 68\n";
+
 require './test.pl';
-curr_test(65);
+curr_test(69);
 
 TODO: {
     local $TODO = 'test explicit return of lval expr';