1 files changed, 7 insertions, 6 deletions
diff --git a/join.rb b/join.rb
index 4522d23..1d2e55d 100644
--- a/join.rb
+++ b/join.rb
@@ -7,24 +7,25 @@ module Puppet::Parser::Functions
     EOS
   ) do |arguments|
 
-    # Technically we support three arguments but only first two are mandatory ....
-    raise(Puppet::ParseError, "Wrong number of arguments " +
+    # Technically we support three arguments but only first two are mandatory ...
+    raise(Puppet::ParseError, "join(): Wrong number of arguments " +
       "given (#{arguments.size} for 2)") if arguments.size < 2
 
     array = arguments[0]
 
     if not array.is_a?(Array)
-      raise(Puppet::ParseError, 'Requires an array to work with')
+      raise(Puppet::ParseError, 'join(): Requires an array to work with')
     end
 
     suffix = arguments[1]
-    prefix = arguments[2]
+    prefix = arguments[2] if arguments[2]
 
-    raise(Puppet::ParseError, 'You must provide suffix ' +
+    raise(Puppet::ParseError, 'join(): You must provide suffix ' +
       'to join array elements with') if suffix.empty?
 
     if prefix and prefix.empty?
-      raise(Puppet::ParseError, 'You must provide prefix to add to join')
+      raise(Puppet::ParseError, 'join(): You must provide prefix ' +
+        'to add to join')
     end
 
     if prefix and not prefix.empty?