Bug 1153125: bug 1051056 causes "Constant subroutine redefined" warnings during t/001compile.t

Bugzilla/API/1_0/Constants.pm

@@ -15,7 +15,7 @@ use Bugzilla::Hook;
 
 use parent qw(Exporter);
 
-our @EXPORT = qw(
+our @EXPORT_OK = qw(
     WS_ERROR_CODE
 
     STATUS_OK

Bugzilla/API/1_0/Resource/Bug.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(STATUS_CREATED);
 use Bugzilla::API::1_0::Util;
 
 use Bugzilla::Comment;

Bugzilla/API/1_0/Resource/Component.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(STATUS_CREATED);
 use Bugzilla::API::1_0::Util;
 
 use Bugzilla::Component;

Bugzilla/API/1_0/Resource/FlagType.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(STATUS_CREATED);
 use Bugzilla::API::1_0::Util;
 
 use Bugzilla::Component;

Bugzilla/API/1_0/Resource/Group.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(STATUS_CREATED);
 use Bugzilla::API::1_0::Util;
 
 use Bugzilla::Constants;

Bugzilla/API/1_0/Resource/Product.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(STATUS_CREATED);
 use Bugzilla::API::1_0::Util;
 
 use Bugzilla::Product;

Bugzilla/API/1_0/Resource/User.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(STATUS_CREATED);
 use Bugzilla::API::1_0::Util;
 
 use Bugzilla::Constants;

Bugzilla/API/1_0/Server.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(API_AUTH_HEADERS);
 use Bugzilla::API::1_0::Util qw(taint_data fix_credentials api_include_exclude);
 
 use Bugzilla::Constants;

Bugzilla/API/1_0/Util.pm

@@ -11,7 +11,7 @@ use 5.10.1;
 use strict;
 use warnings;
 
-use Bugzilla::API::1_0::Constants;
+use Bugzilla::API::1_0::Constants qw(API_AUTH_HEADERS);
 use Bugzilla::Error;
 use Bugzilla::Flag;
 use Bugzilla::FlagType;

Bugzilla/API/Server.pm

@@ -95,25 +95,26 @@ sub server {
 
 sub constants {
     my ($self) = @_;
-    my $api_version = $self->api_version;
+    return $self->{_constants} if defined $self->{_constants};
 
     no strict 'refs';
 
+    my $api_version = $self->api_version;
     my $class = "Bugzilla::API::${api_version}::Constants";
     require_module($class);
 
-    my %constants;
-    foreach my $constant (@{$class . "::EXPORT"}, @{$class . "::EXPORT_OK"}) {
+    $self->{_constants} = {};
+    foreach my $constant (@{$class . "::EXPORT_OK"}) {
         if (ref $class->$constant) {
-            $constants{$constant} = $class->$constant;
+            $self->{_constants}->{$constant} = $class->$constant;
         }
         else {
             my @list = ($class->$constant);
-            $constants{$constant} = (scalar(@list) == 1) ? $list[0] : \@list;
+            $self->{_constants}->{$constant} = (scalar(@list) == 1) ? $list[0] : \@list;
         }
     }
 
-    return \%constants;
+    return $self->{_constants};
 }
 
 sub response_header {