Carpet placed on top of waterlogged block isn't destroyed when you destroy the block.
Carpet stays on top of the water as long as there is water source under it. Updating the carpet doesnt destroy it either.
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We're tracking this issue in MC-17833, so this ticket is being resolved and linked as a duplicate.
That ticket has already been resolved as working as intended, which means this is not considered a bug and won't be fixed. Please do not leave a comment on the linked ticket.
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Duplicate of MC-17833. (See also other linked reports.) l