attribute disambiguation

2 files changed, 6 insertions, 12 deletions

diff --git a/lib/arel/relations/join.rb b/lib/arel/relations/join.rb
index d5ec9d43bd..e5ca49c284 100644
--- a/lib/arel/relations/join.rb
+++ b/lib/arel/relations/join.rb
@@ -24,17 +24,9 @@ module Arel
     end
     
     def prefix_for(attribute)
-      if relation1[attribute] && !relation2[attribute]
-        externalize(relation1).prefix_for(attribute)
-      elsif relation2[attribute] && !relation1[attribute]
-        externalize(relation2).prefix_for(attribute)
-      else
-        if (attribute % relation1[attribute]).size < (attribute % relation2[attribute]).size
-          externalize(relation1).prefix_for(attribute)
-        else
-          externalize(relation2).prefix_for(attribute)
-        end
-      end
+      externalize([relation1[attribute], relation2[attribute]].select { |a| a =~ attribute }.min do |a1, a2|
+        (attribute % a1).size <=> (attribute % a2).size
+      end.relation).prefix_for(attribute)
     end
     
     # TESTME: Not sure which scenario needs this method, was driven by failing tests in ActiveRecord
diff --git a/lib/arel/relations/relation.rb b/lib/arel/relations/relation.rb
index c8602d22e3..3bd40e8f6b 100644
--- a/lib/arel/relations/relation.rb
+++ b/lib/arel/relations/relation.rb
@@ -139,7 +139,9 @@ module Arel
       end
     
       def attribute_for_attribute(attribute)
-        attributes.detect { |a| a =~ attribute }
+        attributes.select { |a| a =~ attribute }.min do |a1, a2|
+          (attribute % a1).size <=> (attribute % a2).size
+        end
       end
     end
     include AttributeAccessors