Coins in frozen blocks can be collected

[Wuzzy2]

SuperTux version: 0.6.1 beta 1
System information: GNU/Linux

Expected behavior

Blocks that are inside a frozen block cannot be collected until the blocks have been destroyed.

Actual behavior

You can collect coins that are inside a frozen block by moving in a “clever” way.

Steps to reproduce actual behavior

1. Play the cave entrance level in Icy Island.
2. Walk right until you reach the section with the coins in side frozen blocks
3. Jump and walk around those blocks very closely so that you touch the frozen block. Eventually the game will award you the coin

Note: I think this bug should be reproducible in any level, feel free to create a test level for that.