From 2a9411bcbc7b49ee159dd75cfdc4d5bbfe7c64ea Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Sun, 4 Jan 2026 20:21:14 +0900
Subject: [PATCH 1/3] Expand GitHub style references in ChangeLog to URL

---
 lib/rdoc/parser/changelog.rb       | 12 ++++++++++++
 test/rdoc/parser/changelog_test.rb | 26 ++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/lib/rdoc/parser/changelog.rb b/lib/rdoc/parser/changelog.rb
index 85ec46e0aa..0356038bf5 100644
--- a/lib/rdoc/parser/changelog.rb
+++ b/lib/rdoc/parser/changelog.rb
@@ -274,6 +274,18 @@ def create_entries(entries)
       def initialize(base, commit, author, email, date, contents)
         case contents
         when String
+          if base&.match(%r[\A([^:/]+:/+[^/]+/)[^/]+/[^/]+/])
+            repo, host = $&, $1
+            contents = contents.dup
+            contents.gsub!(/\b(?:(?i:fix(?:e[sd])?) +)\K#(\d+\b)|\bGH-(\d+)\b|\(\K\#(\d+)(?=\))/) do
+              "[#$&](#{repo}pull/#{$1 || $2 || $3})"
+            end
+            contents.gsub!(%r[(?<![-\w#/@]|\]\[)([-\w]+/[-\w]+)(?:@(\h{8,40})|\#(\d+))(?![-\w#/@]|\]\[)]) do
+              path = defined?($2) ? "commit/#{$2}" : "pull/#{$3}"
+              "[#$&](#{host}#{$1}/#{path})"
+            end
+          end
+
           contents = RDoc::Markdown.parse(contents).parts.each do |body|
             case body
             when RDoc::Markup::Heading
diff --git a/test/rdoc/parser/changelog_test.rb b/test/rdoc/parser/changelog_test.rb
index 562a1c96e3..533c012a54 100644
--- a/test/rdoc/parser/changelog_test.rb
+++ b/test/rdoc/parser/changelog_test.rb
@@ -473,6 +473,32 @@ def test_scan_git_commit_date
     assert_equal expected, @top_level.comment.parse
   end
 
+  def test_scan_git_reference
+    ruby = "https://github.com/ruby/"
+    repo = "#{ruby}ruby/"
+    entry = log_entry("#{repo}commit/",
+                      "a8a989b6f651b878c690f5fd0a728e19a54dd2b9",
+                      "Nobuyoshi Nakada", "nobu@ruby-lang.org",
+                      "2026-01-03 13:28:58 +0900",
+                      <<~LOG)
+      Test net-imap with ruby/net-imap#593
+
+      Fix #15791
+
+      GH-15791
+
+      (#15791)
+
+      Fix up [ruby/net-imap#543].
+      LOG
+    head, *bodies = entry.contents
+    assert_include head.text, "{ruby/net-imap#593}[#{ruby}net-imap/pull/593]"
+    assert_include bodies.shift.text, "Fix {#15791}[#{repo}pull/15791]"
+    assert_include bodies.shift.text, "{GH-15791}[#{repo}pull/15791]"
+    assert_include bodies.shift.text, "({#15791}[#{repo}pull/15791])"
+    assert_include bodies.shift.text, "{ruby/net-imap#543}[#{ruby}net-imap/pull/543]"
+  end
+
   def util_parser(content = '')
     RDoc::Parser::ChangeLog.new @top_level, content, @options, @stats
   end

From 371958bd7b64326f4c4e1d97aa0ce54abcd6fe8f Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Mon, 5 Jan 2026 14:15:34 +0900
Subject: [PATCH 2/3] Adjust styles and add comments

---
 lib/rdoc/parser/changelog.rb | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/lib/rdoc/parser/changelog.rb b/lib/rdoc/parser/changelog.rb
index 0356038bf5..3554594c62 100644
--- a/lib/rdoc/parser/changelog.rb
+++ b/lib/rdoc/parser/changelog.rb
@@ -277,12 +277,21 @@ def initialize(base, commit, author, email, date, contents)
           if base&.match(%r[\A([^:/]+:/+[^/]+/)[^/]+/[^/]+/])
             repo, host = $&, $1
             contents = contents.dup
-            contents.gsub!(/\b(?:(?i:fix(?:e[sd])?) +)\K#(\d+\b)|\bGH-(\d+)\b|\(\K\#(\d+)(?=\))/) do
-              "[#$&](#{repo}pull/#{$1 || $2 || $3})"
+            # base: https://github.com/ruby/ruby/
+            #   Fix #15791 -> Fix [#15791](https://github.com/ruby/ruby/pull/15791)
+            #   GH-15791 -> [GH-15791](https://github.com/ruby/ruby/pull/15791)
+            #   (#15791) -> ([#15791](https://github.com/ruby/ruby/pull/15791))
+            contents.gsub!(/\b(?:(?i:fix(?:e[sd])?) +)\K\#(\d+\b)|\bGH-(\d+)\b|\(\K\#(\d+)(?=\))/) do
+              "[#{$&}](#{repo}pull/#{$1 || $2 || $3})"
             end
+            # repo#PR, repo@HASH
+            #   ruby/ruby#15791 -> [ruby/ruby#15791](https://github.com/ruby/ruby/pull/15791)
+            #   ruby/ruby@a8a989b6 -> [ruby/ruby@a8a989b6](https://github.com/ruby/net-http/commit/a8a989b6)
+            # ref in branckets is not extended
+            #   [ruby/net-imap#543][ruby/ruby#15791] -> [ruby/net-imap#543][ruby/ruby#15791]
             contents.gsub!(%r[(?<![-\w#/@]|\]\[)([-\w]+/[-\w]+)(?:@(\h{8,40})|\#(\d+))(?![-\w#/@]|\]\[)]) do
               path = defined?($2) ? "commit/#{$2}" : "pull/#{$3}"
-              "[#$&](#{host}#{$1}/#{path})"
+              "[#{$&}](#{host}#{$1}/#{path})"
             end
           end
 

From 4341e9e8fe213e392e52c449e5016e1986b14b37 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Wed, 14 Jan 2026 18:57:56 +0900
Subject: [PATCH 3/3] Fix an example in a comment

Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
---
 lib/rdoc/parser/changelog.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/rdoc/parser/changelog.rb b/lib/rdoc/parser/changelog.rb
index 3554594c62..802ac96f01 100644
--- a/lib/rdoc/parser/changelog.rb
+++ b/lib/rdoc/parser/changelog.rb
@@ -286,7 +286,7 @@ def initialize(base, commit, author, email, date, contents)
             end
             # repo#PR, repo@HASH
             #   ruby/ruby#15791 -> [ruby/ruby#15791](https://github.com/ruby/ruby/pull/15791)
-            #   ruby/ruby@a8a989b6 -> [ruby/ruby@a8a989b6](https://github.com/ruby/net-http/commit/a8a989b6)
+            #   ruby/ruby@a8a989b6 -> [ruby/ruby@a8a989b6](https://github.com/ruby/ruby/commit/a8a989b6)
             # ref in branckets is not extended
             #   [ruby/net-imap#543][ruby/ruby#15791] -> [ruby/net-imap#543][ruby/ruby#15791]
             contents.gsub!(%r[(?<![-\w#/@]|\]\[)([-\w]+/[-\w]+)(?:@(\h{8,40})|\#(\d+))(?![-\w#/@]|\]\[)]) do