Improve args validation and add test for RSS version compatibility

Co-authored-by: davorg <24642+davorg@users.noreply.github.com>

Author: Copilot

lib/XML/Feed.pm

@@ -26,18 +26,28 @@ sub new {
 
     # Handle optional args hash
     my %args;
-    if (@_ && ref($_[-1]) eq 'HASH' && exists $_[-1]->{useragent}) {
-        %args = %{pop @_};
-        # Validate useragent parameter
-        if (exists $args{useragent}) {
-            unless (blessed($args{useragent}) && $args{useragent}->isa('LWP::UserAgent')) {
-                Carp::croak("useragent must be an LWP::UserAgent object");
+    if (@_ && ref($_[-1]) eq 'HASH') {
+        my $potential_args = $_[-1];
+        # Check if this looks like our args hash (has known keys)
+        my @known_keys = qw(useragent);
+        my @hash_keys = keys %$potential_args;
+        
+        # If any key matches our known args, treat it as args hash
+        if (grep { my $k = $_; grep { $k eq $_ } @known_keys } @hash_keys) {
+            %args = %{pop @_};
+            
+            # Validate useragent parameter if provided
+            if (exists $args{useragent}) {
+                unless (blessed($args{useragent}) && $args{useragent}->isa('LWP::UserAgent')) {
+                    Carp::croak("useragent must be an LWP::UserAgent object");
+                }
+            }
+            
+            # Only known keys are allowed
+            my @invalid_keys = grep { my $k = $_; !grep { $k eq $_ } @known_keys } keys %args;
+            if (@invalid_keys) {
+                Carp::croak("Invalid argument(s): " . join(', ', @invalid_keys));
             }
-        }
-        # Only useragent is allowed for now
-        my @invalid_keys = grep { $_ ne 'useragent' } keys %args;
-        if (@invalid_keys) {
-            Carp::croak("Invalid argument(s): " . join(', ', @invalid_keys));
         }
     }
 

t/31-useragent.t

@@ -93,7 +93,18 @@ use LWP::UserAgent;
     is($feed->useragent->agent, 'RSSTestAgent/1.0', 'UserAgent preserved in RSS feed');
 }
 
-# Test 10: LWP::UserAgent subclass should be accepted
+# Test 10: RSS feed with both version and useragent
+{
+    my $ua = LWP::UserAgent->new;
+    $ua->agent('RSSTestAgent/2.0');
+    
+    my $feed = XML::Feed->new('RSS', version => '0.91', { useragent => $ua });
+    isa_ok($feed, 'XML::Feed::Format::RSS', 'RSS feed created with version and useragent');
+    like($feed->format, qr/0\.91/, 'RSS version is correct');
+    is($feed->useragent->agent, 'RSSTestAgent/2.0', 'UserAgent preserved');
+}
+
+# Test 11: LWP::UserAgent subclass should be accepted
 SKIP: {
     skip "Creating subclass inline for testing", 2;