From f3b389aa9ecaeed7fb8ca4eb7628eb88af209524 Mon Sep 17 00:00:00 2001
From: zzak <zzakscott@gmail.com>
Date: Sat, 4 Mar 2023 22:24:01 +0900
Subject: [PATCH] Isolate root dir if specified

This ensures only files from the root directory are chosen, in order to allow a clean build from outside the source directory.
---
 lib/rdoc/options.rb | 5 +++--
 lib/rdoc/rdoc.rb    | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/rdoc/options.rb b/lib/rdoc/options.rb
index eed0f6b39b..6ee29fd071 100644
--- a/lib/rdoc/options.rb
+++ b/lib/rdoc/options.rb
@@ -565,9 +565,10 @@ def finish
 
     @op_dir ||= 'doc'
 
-    @rdoc_include << "." if @rdoc_include.empty?
     root = @root.to_s
-    @rdoc_include << root unless @rdoc_include.include?(root)
+    if @rdoc_include.empty? || !@rdoc_include.include?(root)
+      @rdoc_include << root
+    end
 
     @exclude = self.exclude
 
diff --git a/lib/rdoc/rdoc.rb b/lib/rdoc/rdoc.rb
index 7e17b71d6b..2da6d9b575 100644
--- a/lib/rdoc/rdoc.rb
+++ b/lib/rdoc/rdoc.rb
@@ -119,7 +119,7 @@ def error(msg)
   # +files+.
 
   def gather_files files
-    files = ["."] if files.empty?
+    files = [@options.root.to_s] if files.empty?
 
     file_list = normalized_file_list files, true, @options.exclude