[FIX] Update README to include Mercurial references.

Author: Robin Luckey

README

@@ -34,21 +34,22 @@ Ohloh SCM does not support Windows.
 
 Ohloh SCM targets Ruby 1.8.6 and Rake 0.8.1
 
-Ohloh SCM interfaces with CVSNT, Subversion, and Git through the shell.
-In order to pass the unit tests, all three systems must be installed and
-on your path. Ohloh uses the following versions, and other versions are
+Ohloh SCM interfaces with CVSNT, Subversion, Git and Mercurial through the
+shell.  In order to pass the unit tests, all three systems must be installed
+and on your path. Ohloh uses the following versions, and other versions are
 totally unsupported at this time:
 
 cvsnt 2.5.03
 svn 1.4.2
 git 1.6.0.4
+hg 1.1.2
 
 If you are using CVS instead of CVSNT, you can potentially try creating
 a shell alias or symlink mapping 'cvsnt' to 'cvs'.
 
 == Running
 
-Ensure that cvsnt, svn, svnadmin, svnsync, and git are all on your path.
+Ensure that cvsnt, svn, svnadmin, svnsync, git, and hg are all on your path.
 Then you can run the unit tests:
 
 $ rake

lib/scm/adapters/hg/commits.rb

@@ -61,7 +61,7 @@ def open_log_file(since=0)
 					# As a time optimization, just create an empty file rather than fetch a log we know will be empty.
 					File.open(log_filename, 'w') { }
 				else
-					run "cd '#{url}' && hg log --verbose -r #{since}:tip --style #{Scm::Parsers::HgStyledParser.verbose_style_path} > #{log_filename}"
+					run "cd '#{url}' && hg log --verbose -r #{since || 0}:tip --style #{Scm::Parsers::HgStyledParser.verbose_style_path} > #{log_filename}"
 				end
 				File.open(log_filename, 'r') { |io| yield io }
 			ensure