Fix: Handle relative URLs in HTTP redirects

Fixes #442

Author: langtind

lib/u3d/utils.rb

@@ -84,8 +84,11 @@ def follow_redirects(url, redirect_limit: 10, http_method: :get, request_headers
         when Net::HTTPSuccess
           yield(request, response)
         when Net::HTTPRedirection
-          UI.verbose "Redirected to #{response['location']}"
-          follow_redirects(response['location'], redirect_limit: redirect_limit - 1, http_method: http_method, request_headers: request_headers, &block)
+          location = response['location']
+          # Handle relative URLs in redirects
+          location = (uri + location).to_s if location && !location.start_with?('http://', 'https://')
+          UI.verbose "Redirected to #{location}"
+          follow_redirects(location, redirect_limit: redirect_limit - 1, http_method: http_method, request_headers: request_headers, &block)
         else raise "Request failed with status #{response.code}"
         end
       end

spec/u3d/utils_spec.rb

@@ -105,5 +105,47 @@
         end
       end
     end
+
+    describe '.follow_redirects' do
+      it 'handles relative URLs in redirects' do
+        http_mock = double('http')
+        redirect_response = double('redirect_response')
+        success_response = double('success_response')
+
+        # First request returns redirect with relative URL
+        allow(redirect_response).to receive(:kind_of?).with(Net::HTTPSuccess).and_return(false)
+        allow(redirect_response).to receive(:kind_of?).with(Net::HTTPRedirection).and_return(true)
+        allow(Net::HTTPSuccess).to receive(:===).with(redirect_response).and_return(false)
+        allow(Net::HTTPRedirection).to receive(:===).with(redirect_response).and_return(true)
+        allow(redirect_response).to receive(:[]).with('location').and_return('/new-path')
+        allow(redirect_response).to receive(:code).and_return('302')
+
+        # Second request succeeds
+        allow(success_response).to receive(:kind_of?).with(Net::HTTPSuccess).and_return(true)
+        allow(success_response).to receive(:kind_of?).with(Net::HTTPRedirection).and_return(false)
+        allow(Net::HTTPSuccess).to receive(:===).with(success_response).and_return(true)
+        allow(Net::HTTPRedirection).to receive(:===).with(success_response).and_return(false)
+        allow(success_response).to receive(:body).and_return('success')
+        allow(success_response).to receive(:code).and_return('200')
+
+        call_count = 0
+        allow(Net::HTTP).to receive(:start) do |host, port, _opts, &block|
+          call_count += 1
+          expect(host).to eq('example.com')
+          expect(port).to eq(443)
+          allow(http_mock).to receive(:request) do
+            call_count == 1 ? redirect_response : success_response
+          end
+          block.call(http_mock)
+        end
+
+        result = U3d::Utils.follow_redirects('https://example.com/original') do |_request, response|
+          response.body
+        end
+
+        expect(result).to eql('success')
+        expect(call_count).to eq(2)
+      end
+    end
   end
 end