Fix issue #206 - raise an error on enums with duplicate keys

2 files changed, 6 insertions, 1 deletions

diff --git a/lib/ffi/enum.rb b/lib/ffi/enum.rb
index a68f16b..0438482 100644
--- a/lib/ffi/enum.rb
+++ b/lib/ffi/enum.rb
@@ -86,6 +86,7 @@ module FFI
         info.each do |i|
           case i
           when Symbol
+            raise ArgumentError, "duplicate enum key" if @kv_map.has_key?(i)
             @kv_map[i] = value
             last_cst = i
             value += 1
@@ -95,7 +96,7 @@ module FFI
           end
         end
       end
-      @vk_map = Hash[@kv_map.map{|k,v| [v,k]}]
+      @vk_map = @kv_map.invert
     end
 
     # @return [Array] enum symbol names
diff --git a/spec/ffi/enum_spec.rb b/spec/ffi/enum_spec.rb
index db6d6d2..8d4c5c9 100644
--- a/spec/ffi/enum_spec.rb
+++ b/spec/ffi/enum_spec.rb
@@ -224,4 +224,8 @@ describe "All enums" do
     enum[42424241].should eq nil
     enum[42424243].should eq nil
   end
+
+  it "duplicate enum keys rejected" do
+    lambda { enum [ :a, 0xfee1dead, :b, 0xdeadbeef, :a, 0 ] }.should raise_error
+  end
 end