From: Gisle Aas <gisle@aas.no>
Date: Fri, 21 Oct 2005 08:04:40 +0000 (-0700)
Subject: allow "" as select bitmask [PATCH]
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=15547071d7923e1ad71df03a6a5f4bf10b39825e;p=p5sagit%2Fp5-mst-13.2.git

allow "" as select bitmask [PATCH]
Message-ID: <lrach229o7.fsf_-_@caliper.activestate.com>

p4raw-id: //depot/perl@25818
---

diff --git a/pp_sys.c b/pp_sys.c
index cf6a862..b907093 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -1031,14 +1031,14 @@ PP(pp_sselect)
     SP -= 4;
     for (i = 1; i <= 3; i++) {
 	SV *sv = SP[i];
-	if (SvOK(sv) && SvREADONLY(sv)) {
+	if (!SvOK(sv))
+	    continue;
+	if (SvREADONLY(sv)) {
 	    if (SvIsCOW(sv))
 		sv_force_normal_flags(sv, 0);
-	    if (SvREADONLY(sv))
+	    if (SvREADONLY(sv) && !(SvPOK(sv) && SvCUR(sv) == 0))
 		DIE(aTHX_ PL_no_modify);
 	}
-	if (!SvOK(sv))
-	    continue;
 	if (!SvPOK(sv)) {
 	    if (ckWARN(WARN_MISC))
                 Perl_warner(aTHX_ packWARN(WARN_MISC), "Non-string passed as bitmask");
@@ -1093,7 +1093,7 @@ PP(pp_sselect)
 
     for (i = 1; i <= 3; i++) {
 	sv = SP[i];
-	if (!SvOK(sv)) {
+	if (!SvOK(sv) || SvCUR(sv) == 0) {
 	    fd_sets[i] = 0;
 	    continue;
 	}
diff --git a/t/op/sselect.t b/t/op/sselect.t
index 4e50b29..0f877b1 100644
--- a/t/op/sselect.t
+++ b/t/op/sselect.t
@@ -7,7 +7,7 @@ BEGIN {
 
 require 'test.pl';
 
-plan (6);
+plan (9);
 
 my $blank = "";
 eval {select undef, $blank, $blank, 0};
@@ -18,8 +18,15 @@ eval {select $blank, $blank, undef, 0};
 is ($@, "");
 
 eval {select "", $blank, $blank, 0};
-like ($@, qr/^Modification of a read-only value attempted/);
+is ($@, "");
 eval {select $blank, "", $blank, 0};
-like ($@, qr/^Modification of a read-only value attempted/);
+is ($@, "");
 eval {select $blank, $blank, "", 0};
+is ($@, "");
+
+eval {select "a", $blank, $blank, 0};
+like ($@, qr/^Modification of a read-only value attempted/);
+eval {select $blank, "a", $blank, 0};
+like ($@, qr/^Modification of a read-only value attempted/);
+eval {select $blank, $blank, "a", 0};
 like ($@, qr/^Modification of a read-only value attempted/);