1 files changed, 24 insertions, 9 deletions

diff --git a/lib/rubygems/commands/rdoc_command.rb b/lib/rubygems/commands/rdoc_command.rb
index 92f215705a..ea0f3ad592 100644
--- a/lib/rubygems/commands/rdoc_command.rb
+++ b/lib/rubygems/commands/rdoc_command.rb
@@ -8,7 +8,7 @@ class Gem::Commands::RdocCommand < Gem::Command
   def initialize
     super 'rdoc', 'Generates RDoc for pre-installed gems',
           :version => Gem::Requirement.default,
-          :include_rdoc => true, :include_ri => true
+          :include_rdoc => true, :include_ri => true, :overwrite => false
 
     add_option('--all',
                'Generate RDoc/RI documentation for all',
@@ -17,15 +17,20 @@ class Gem::Commands::RdocCommand < Gem::Command
     end
 
     add_option('--[no-]rdoc',
-               'Include RDoc generated documents') do |value, options|
+               'Generate RDoc HTML') do |value, options|
       options[:include_rdoc] = value
     end
 
     add_option('--[no-]ri',
-               'Include RI generated documents') do |value, options|
+               'Generate RI data') do |value, options|
       options[:include_ri] = value
     end
 
+    add_option('--[no-]overwrite',
+               'Overwrite installed documents') do |value, options|
+      options[:overwrite] = value
+    end
+
     add_version_option
   end
 
@@ -34,7 +39,14 @@ class Gem::Commands::RdocCommand < Gem::Command
   end
 
   def defaults_str # :nodoc:
-    "--version '#{Gem::Requirement.default}' --rdoc --ri"
+    "--version '#{Gem::Requirement.default}' --rdoc --ri --no-overwrite"
+  end
+
+  def description # :nodoc:
+    <<-DESC
+The rdoc command builds RDoc and RI documentation for installed gems.  Use
+--overwrite to force rebuilding of documentation.
+    DESC
   end
 
   def usage # :nodoc:
@@ -53,24 +65,27 @@ class Gem::Commands::RdocCommand < Gem::Command
     end
 
     if specs.empty?
-      fail "Failed to find gem #{gem_name} to generate RDoc for #{options[:version]}"
+      raise "Failed to find gem #{gem_name} to generate RDoc for #{options[:version]}"
     end
 
     if options[:include_ri]
-      specs.each do |spec|
-        Gem::DocManager.new(spec).generate_ri
+      specs.sort.each do |spec|
+        doc = Gem::DocManager.new(spec)
+        doc.generate_ri if options[:overwrite] || !doc.ri_installed?
       end
 
       Gem::DocManager.update_ri_cache
     end
 
     if options[:include_rdoc]
-      specs.each do |spec|
-        Gem::DocManager.new(spec).generate_rdoc
+      specs.sort.each do |spec|
+        doc = Gem::DocManager.new(spec)
+        doc.generate_rdoc if options[:overwrite] || !doc.rdoc_installed?
       end
     end
 
     true
   end
+
 end