Fix an edge case of non-Int being wrongly validated as Int

t/101_issues/Int.t

@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use Test::More;
+use Mouse::Util::TypeConstraints;
+
+my $Int = find_type_constraint 'Int';
+
+subtest "Non-Int from numerical literal: my \$num = 3.14", sub {
+    my $num = 3.14;
+    ok !$Int->check($num), "\$num is not Int";
+    { no warnings; int($num) };
+    ok !$Int->check($num), "\$num is still not Int";
+};
+
+subtest "Non-Int from string literal: my \$num = \"3.14\"", sub {
+    my $num = "3.14";
+    ok !$Int->check($num), "\$num is not Int";
+    { no warnings; int($num) };
+    ok !$Int->check($num), "\$num is still not Int";
+};
+
+subtest "Int from string literal: my \$num = \"3\"", sub {
+    my $num = "3";
+    ok $Int->check($num), "\$num is Int";
+    { no warnings; int($num) };
+    ok $Int->check($num), "\$num is still Int";
+};
+
+subtest "Int from integer literal: my \$num = 3", sub {
+    my $num = 3;
+    ok $Int->check($num), "\$num is Int";
+    { no warnings; int($num) };
+    ok $Int->check($num), "\$num is still Int";
+};
+
+subtest "MAXUINT", sub {
+    my $maxuint = ~0;
+    ok $Int->check( $maxuint ), 'yes MAXUINT';
+    my $as_string = sprintf '%f', $maxuint;
+    ok $Int->check( $maxuint ), 'yes MAXUINT after use as float';
+};
+
+done_testing;

xs-src/MouseTypeConstraints.xs

@@ -168,16 +168,21 @@ S_nv_is_integer(pTHX_ NV const nv) {
 int
 mouse_tc_Int(pTHX_ SV* const data PERL_UNUSED_DECL, SV* const sv) {
     assert(sv);
-    if(SvPOKp(sv)){
+
+    if(SvPOK(sv)){
         int const num_type = grok_number(SvPVX(sv), SvCUR(sv), NULL);
         return num_type && !(num_type & IS_NUMBER_NOT_INT);
     }
-    else if(SvIOKp(sv)){
+    else if(SvIOK(sv)){
         return TRUE;
     }
-    else if(SvNOKp(sv)) {
+    else if(SvNOK(sv)) {
         return S_nv_is_integer(aTHX_ SvNVX(sv));
     }
+    else if (SvOK(sv) && (SvMAGIC(sv) || SvTYPE(sv) == SVt_PVMG) && SvIOKp(sv)) {
+        return TRUE;
+    }
+
     return FALSE;
 }