[C#] Error Storing Dictionary : desgin scarlar type as the "key" field

[liuxinjia]

It works fine when designing string filed as the "key" field. But problem happens when I use one of ushort field as the key .

[Fbs file]

[TestCode]

• [C#, Windows, master]

[dbaileychess]

Can you share the generated code of CreateSortedVectorOfIntItem for both the string an ushort keys?

[liuxinjia]

The gen code of int key :

The gen code of string key:

Sorry for not replying in time😁 @dbaileychess

[dbaileychess]

It seems the String generated code is not correct, I'm not sure why it is comparing Ushort values when it should be comparing strings: https://github.com/google/flatbuffers/blob/8d1cc6ac7d9c750fef41f01012726a7d431be589/src/idl_gen_csharp.cpp#L625-L639

Could you give the schema for both the int and string keys? Perhaps name them something unique that won't clash with with types (Foo == string key and Bar == int key)

[liuxinjia]

Sorry for posting the wrong gen code for string keys.🤣 --the schema

-- the gen code of CreateSortedVectorOfStrItem

@dbaileychess But the problem occurs when I use ushort field as the key. Below is my complete test code.

-- the schema

-- the Test code

[dbaileychess]

It appears the issue is due to having a key == 0. If I set the keys to [1,2,3,4] everything works. Looking into this more.

[dbaileychess]

Ah, I remember this from the Java implementation, the default value for the IntItem.id is 0, and we don't push default values into the buffer unless 'ForceDefaults' is enabled. So when it is doing the binary search, it doesn't account for the default value and fails.

[dbaileychess]

This is leading to a bigger bug :( If you leave your code as is, and just change AddCount(fbb, i+1) it works. That's because, if any of the IntItem fields are non-default values, it will be written correctly to the buffer. However, if all the fields are defaulted, it isn't written to the buffer and the following fails:

 Assert.IsTrue(dict.Dict(0) != null);
Assert.IsTrue(dict.Dict(0).Value.Count == 0);

Which is a little scary, since the first Dict item should have a count of 0. But it is actually 1.