fix(yjs): let the server decide who seeds an empty room - #3331
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fix(yjs): let the server decide who seeds an empty room#3331JammingBen wants to merge 2 commits into
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Two clients opening the same file at once could both seed the Y.Doc, and the room then held the body twice. The awareness election that guarded this only waited a guessed 150ms, and a client has no signal that its announce is visible to everyone. The Yjs server now grants seeding to exactly one connection per room. It is the only party that sees every connection at once, so no wait has to be guessed. The grant is permission, not an instruction: the client still checks its own document first, so a grant for a room that already has content costs nothing. It passes to another writer when the holder leaves, and dies with the room.
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Two clients opening the same file at once could both seed the Y.Doc, and the room then held the body twice. The awareness election that guarded this only waited a guessed 150ms.
Instead of solving this on the client side, the Yjs server now grants seeding to exactly one connection per room. It is the only party that sees every connection at once.
The grant is permission, not an instruction: the client still checks its own document first, so a grant for a room that already has content costs nothing. It passes to another writer when the holder leaves, and dies with the room.
fixes #3141