fcl-stl THashMap iterator skips first element

Summary

It seems that when iterating through a THashMap (fcl-stl), one of the elements is always not returned.

System Information

• Operating system: Xubuntu GNU/Linux
• Processor architecture: x86-64
• Compiler version: 3.2.3
• Device: PC

Lazarus 2.2.7 (rev ada7a90f86) FPC 3.2.3 x86_64-linux-gtk2

Steps to reproduce

1. Create a THashMap instance.
2. Add 2 items to it
3. Use a for loop to iterate through it
4. Notice that only 1 item is returned

Example Project

program project1;

uses ghashmap;

type
  { TIntHashFunc }

  TIntHashFunc = class
    class function hash(a: Integer; n: SizeUInt): SizeUInt;
  end;

  TIntHash = specialize THashmap<Integer, Integer, TIntHashFunc>;

{ TIntHashFunc }

class function TIntHashFunc.hash(a: Integer; n: SizeUInt): SizeUInt;
begin
  Result := a mod n;
end;

var
  Hash: TIntHash;
  Pair: TIntHash.TPair;
begin
  Hash := TIntHash.Create;
  Hash.insert(0, 5);
  Hash.insert(1, 6);

  for Pair in Hash do
    writeln(pair.key, ' ', pair.value);
end.