1 files changed, 33 insertions, 4 deletions
diff --git a/railties/lib/rails/gem_dependency.rb b/railties/lib/rails/gem_dependency.rb
index ffdc403700..80481859e1 100644
--- a/railties/lib/rails/gem_dependency.rb
+++ b/railties/lib/rails/gem_dependency.rb
@@ -82,6 +82,10 @@ module Rails
       File.join(base_directory, specification.full_name)
     end
 
+    def spec_filename(base_directory)
+      File.join(gem_dir(base_directory), '.specification')
+    end
+
     def load
       return if @loaded || @load_paths_added == false
       require(@lib || name) unless @lib == false
@@ -146,17 +150,42 @@ module Rails
         Gem::GemRunner.new.run(unpack_command)
       end
 
+      # Gem.activate changes the spec - get the original
+      real_spec = Gem::Specification.load(spec.loaded_from)
+      write_spec(directory, real_spec)
+
+    end
+
+    def write_spec(directory, spec)
       # copy the gem's specification into GEMDIR/.specification so that
       # we can access information about the gem on deployment systems
       # without having the gem installed
-      spec_filename = File.join(gem_dir(directory), '.specification')
-      # Gem.activate changes the spec - get the original
-      spec = Gem::Specification.load(specification.loaded_from)
-      File.open(spec_filename, 'w') do |file|
+      File.open(spec_filename(directory), 'w') do |file|
         file.puts spec.to_yaml
       end
     end
 
+    def refresh_spec(directory)
+      real_gems = Gem.source_index.installed_source_index
+      exact_dep = Gem::Dependency.new(name, "= #{specification.version}")
+      matches = real_gems.search(exact_dep)
+      installed_spec = matches.first
+      if installed_spec
+        # we have a real copy
+        # get a fresh spec - matches should only have one element
+        # note that there is no reliable method to check that the loaded
+        # spec is the same as the copy from real_gems - Gem.activate changes
+        # some of the fields
+        real_spec = Gem::Specification.load(matches.first.loaded_from)
+        write_spec(directory, real_spec)
+        puts "Reloaded specification for #{name} from installed gems."
+      else
+        # the gem isn't installed locally - write out our current specs
+        write_spec(directory, specification)
+        puts "Gem #{name} not loaded locally - writing out current spec."
+      end
+    end
+
     def ==(other)
       self.name == other.name && self.requirement == other.requirement
     end