local variable re-assignment in rescue block doesn't merge types only after that point

[rdp]

The following works (extracted from server.cr):

  def handle_client(io)
    io.sync = false
      if tls = @tls
        io = OpenSSL::SSL::Socket::Server.new(io, tls, sync_close: true)
      end
    @processor.process(io, io)
  end

However this doesn't:

  def handle_client(io)
    io.sync = false
      if tls = @tls
         begin
            io = OpenSSL::SSL::Socket::Server.new(io, tls, sync_close: true)
         rescue ex
         end
      end
    @processor.process(io, io)
  end

crystal/src/http/server.cr:163: undefined method 'sync=' for Nil (compile-time type is (TCPSocket | Nil))
    io.sync = false

So I guess the parser is assigning the type "global to the method" in the latter case, which surprised me at the time, and may not be expected.

Thanks!

[asterite]

a = 1
b = a
begin
  a = 'a'
rescue
end
p typeof(b) # => Int32 | Char

but it should be Int32