Internals::SvREFCNT() now treats reference counts as unsigned

Previously setting a large (negative in 32-bit signed) reference count
would be returned as a positive number on 64-bit builds and negative
on 32-bit builds.

2 files changed, 11 insertions, 4 deletions

diff --git a/lib/Internals.t b/lib/Internals.t
index d6c2367436..d3fce9c1c8 100644
--- a/lib/Internals.t
+++ b/lib/Internals.t
@@ -7,7 +7,7 @@ BEGIN {
     }
 }
 
-use Test::More tests => 76;
+use Test::More tests => 78;
 
 my $ro_err = qr/^Modification of a read-only value attempted/;
 
@@ -166,4 +166,11 @@ is(  Internals::SvREFCNT($foo{foo}), 1 );
 is(  Internals::SvREFCNT($foo, 2), 2, "update ref count");
 is(  Internals::SvREFCNT($foo), 2, "check we got the stored value");
 
+# the reference count is a U16, but was returned as an IV resulting in
+# different values between 32 and 64-bit builds
+my $big_count = 0xFFFFFFF0; # -16 32-bit signed
+is( Internals::SvREFCNT($foo, $big_count), $big_count,
+    "set reference count unsigned");
+is( Internals::SvREFCNT($foo), $big_count, "reference count unsigned");
+
 Internals::SvREFCNT($foo, 1 );
diff --git a/universal.c b/universal.c
index 0599e6795d..6ea0e29cb1 100644
--- a/universal.c
+++ b/universal.c
@@ -924,11 +924,11 @@ XS(XS_Internals_SvREFCNT)	/* This is dangerous stuff. */
     sv = SvRV(svz);
 
     if (items == 1)
-	 XSRETURN_IV(SvREFCNT(sv) - 1); /* Minus the ref created for us. */
+	 XSRETURN_UV(SvREFCNT(sv) - 1); /* Minus the ref created for us. */
     else if (items == 2) {
          /* I hope you really know what you are doing. */
-	 SvREFCNT(sv) = SvIV(ST(1)) + 1; /* we free one ref on exit */
-	 XSRETURN_IV(SvREFCNT(sv) - 1);
+	 SvREFCNT(sv) = SvUV(ST(1)) + 1; /* we free one ref on exit */
+	 XSRETURN_UV(SvREFCNT(sv) - 1);
     }
     XSRETURN_UNDEF; /* Can't happen. */
 }