[zisunny104]

BlockLeaves reads and writes the two decay-related flags on the wrong bits, so leaves that should be persistent decay, and player-placed leaves are not persistent.

The bundled palette (runtime_block_states.dat) maps the block states like this:

Block	meta	persistent_bit	update_bit
oak_leaves (18)	4	0	1
oak_leaves (18)	8	1	0
azalea / cherry / mangrove leaves	1	0	1
azalea / cherry / mangrove leaves	2	1	0

So for the base leaves persistent is 0x08 and the update/check-decay flag is 0x04. BlockLeaves had them the other way round:

• isPersistent() checked 0x04, isCheckDecay() checked 0x08, and both setters wrote the opposite bit. A leaf loaded as persistent_bit=1 (meta 8) therefore reports persistent=false, checkDecay=true and is removed by the next random tick when no log is nearby.
• place() calls setPersistent(true), which set 0x04, i.e. the update bit, not the persistent bit.
• In BlockAzaleaLeaves, BlockCherryLeaves and BlockLeavesMangrove, setPersistent() cleared bit 1 (~1, the update bit) instead of bit 2 (~2). It wiped the update flag and could not clear persistence.

Changes

• BlockLeaves: isPersistent/setPersistent use 0x08; isCheckDecay/setCheckDecay use 0x04.
• Azalea, cherry and mangrove leaves: setPersistent clears ~2 so only the persistent bit changes. Flowering azalea inherits the fix.
• Species bits and the decay logic itself are unchanged.

Testing

• Read the palette entries for oak, azalea, cherry and mangrove leaves in runtime_block_states.dat and checked the getters/setters against them by reading the code. The other leaf types were not individually checked.
• Checked manually on a local server built from this branch: a leaf block placed with no log nearby stays in place.

🤖 Generated with Claude Code

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[PetteriM1]

The problem is what happens to already placed leaves after this change

[zisunny104]

我是因為發現地圖內由玩家放置的樹葉方塊建築開始消失，才發現一些方塊的狀態可能錯誤設置。

經過這樣的修正，手動放置的樹葉方塊就不會自然消失（錯誤狀態）了。

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I discovered that some block states might have been set incorrectly after noticing that leaf block structures placed by players in the world were starting to disappear.

With this fix, manually placed leaf blocks will no longer decay naturally due to incorrect block states.