Puppet service resource keeps getting (re-)enabled

Question

We created a new service provider for Puppet. However, when using that provider the service keeps getting (re-)enabled with every Puppet run:

Notice: /Stage[main]/Profiles::Base/Service[foo]/enable: enable changed 'true' to 'true'

Debug output shows that the service already is enabled (and running), but it's still getting enabled again:

Debug: Executing: '/usr/bin/svctl isup foo'
Debug: foo is running
Debug: Executing: '/usr/bin/svctl isenabled foo'
Debug: foo is enabled
Debug: Executing: '/usr/bin/svctl enable foo'
Debug: Executing: '/usr/bin/svctl update'
Debug: foo has been enabled
Notice: /Stage[main]/Profiles::Base/Service[foo]/enable: enable changed 'true' to 'true'

These are the relevant parts of the provider code:

commands :svctl => "svctl"

# ... 

def enabled?
  begin
    svctl(["isenabled", @resource[:name]])
    return true
  rescue Puppet::ExecutionFailure => e
    if $?.exitstatus == 1
      return false
    else
      return nil 
    end 
  end 
end 

def enable
  begin
    svctl(["enable", @resource[:name]])
    self.updatecmd
  rescue Puppet::ExecutionFailure => e
    return nil 
  end 
end 

Answer 1

Turns out, the problem was that the provider's enabled? method returned the objects true/false instead of the symbols :true/:false (note the leading colons).

After changing true and false to :true and :false respectively, the problem disappeared.