Merge branch 'lzap-rake-enhance-nil'

Author: hsbt

lib/rake/task_manager.rb

@@ -127,7 +127,7 @@ def enhance_with_matching_rule(task_name, level=0)
       fail Rake::RuleRecursionOverflowError,
         "Rule Recursion Too Deep" if level >= 16
       @rules.each do |pattern, args, extensions, block|
-        if pattern.match(task_name)
+        if pattern && pattern.match(task_name)
           task = attempt_rule(task_name, pattern, args, extensions, block, level)
           return task if task
         end