[ruby/rdoc] Support different drive latters in include paths

https://github.com/ruby/rdoc/commit/946d2592e2

lib/rdoc/options.rb

@@ -555,7 +555,13 @@ class RDoc::Options
 
     @files << @page_dir.to_s
 
-    page_dir = @page_dir.expand_path.relative_path_from @root
+    page_dir = nil
+    begin
+      page_dir = @page_dir.expand_path.relative_path_from @root
+    rescue ArgumentError
+      # On Windows, sometimes crosses different drive letters.
+      page_dir = @page_dir.expand_path
+    end
 
     @page_dir = page_dir
   end
@@ -1154,8 +1160,17 @@ Usage: #{opt.program_name} [options] [names...]
 
     path.reject do |item|
       path = Pathname.new(item).expand_path
-      relative = path.relative_path_from(dot).to_s
+      is_reject = nil
-      relative.start_with? '..'
+      relative = nil
+      begin
+        relative = path.relative_path_from(dot).to_s
+      rescue ArgumentError
+        # On Windows, sometimes crosses different drive letters.
+        is_reject = true
+      else
+        is_reject = relative.start_with? '..'
+      end
+      is_reject
     end
   end
 

test/rdoc/test_rdoc_options.rb

@@ -507,8 +507,14 @@ rdoc_include:
     assert_empty out
     assert_empty err
 
-    expected =
+    expected = nil
-      Pathname(Dir.tmpdir).expand_path.relative_path_from @options.root
+    begin
+      expected =
+        Pathname(Dir.tmpdir).expand_path.relative_path_from @options.root
+    rescue ArgumentError
+      # On Windows, sometimes crosses different drive letters.
+      expected = Pathname(Dir.tmpdir).expand_path
+    end
 
     assert_equal expected,     @options.page_dir
     assert_equal [Dir.tmpdir], @options.files