Merge pull request #14176 from Frederick888/curl_follow_redirection

Curl: Fix following redirections when base changes

Library/Homebrew/download_strategy.rb

@@ -471,7 +471,7 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
 
     lines = output.to_s.lines.map(&:chomp)
 
-    final_url = curl_response_last_location(parsed_output[:responses], absolutize: true, base_url: url)
+    final_url = curl_response_follow_redirections(parsed_output[:responses], url)
     final_url ||= url
 
     content_disposition_parser = Mechanize::HTTP::ContentDispositionParser.new

Library/Homebrew/test/utils/curl_spec.rb

@@ -556,4 +556,58 @@ describe "Utils::Curl" do
       expect(curl_response_last_location([response_hash[:ok]])).to be_nil
     end
   end
+
+  describe "#curl_response_follow_redirections" do
+    it "returns the original URL when there are no location headers" do
+      expect(
+        curl_response_follow_redirections(
+          [response_hash[:ok]],
+          "https://brew.sh/test1/test2",
+        ),
+      ).to eq("https://brew.sh/test1/test2")
+    end
+
+    it "returns the URL relative to base when locations are relative" do
+      expect(
+        curl_response_follow_redirections(
+          [response_hash[:redirection_root_relative], response_hash[:ok]],
+          "https://brew.sh/test1/test2",
+        ),
+      ).to eq("https://brew.sh/example/")
+
+      expect(
+        curl_response_follow_redirections(
+          [response_hash[:redirection_parent_relative], response_hash[:ok]],
+          "https://brew.sh/test1/test2",
+        ),
+      ).to eq("https://brew.sh/test1/example/")
+
+      expect(
+        curl_response_follow_redirections(
+          [
+            response_hash[:redirection_parent_relative],
+            response_hash[:redirection_parent_relative],
+            response_hash[:ok],
+          ],
+          "https://brew.sh/test1/test2",
+        ),
+      ).to eq("https://brew.sh/test1/example/example/")
+    end
+
+    it "returns new base when there are absolute location(s)" do
+      expect(
+        curl_response_follow_redirections(
+          [response_hash[:redirection], response_hash[:ok]],
+          "https://brew.sh/test1/test2",
+        ),
+      ).to eq(location_urls[0])
+
+      expect(
+        curl_response_follow_redirections(
+          [response_hash[:redirection], response_hash[:redirection_parent_relative], response_hash[:ok]],
+          "https://brew.sh/test1/test2",
+        ),
+      ).to eq("#{location_urls[0]}example/")
+    end
+  end
 end

Library/Homebrew/utils/curl.rb

@@ -506,6 +506,30 @@ module Utils
       nil
     end
 
+    # Returns the final URL by following location headers in cURL responses.
+    # @param responses [Array<Hash>] An array of hashes containing response
+    #   status information and headers from `#parse_curl_response`.
+    # @param base_url [String] The URL to use as a base.
+    # @return [String] The final absolute URL after redirections.
+    sig {
+      params(
+        responses: T::Array[T::Hash[Symbol, T.untyped]],
+        base_url:  String,
+      ).returns(String)
+    }
+    def curl_response_follow_redirections(responses, base_url)
+      responses.each do |response|
+        next if response[:headers].blank?
+
+        location = response[:headers]["location"]
+        next if location.blank?
+
+        base_url = URI.join(base_url, location).to_s
+      end
+
+      base_url
+    end
+
     private
 
     # Parses HTTP response text from `curl` output into a hash containing the