If you are in creative mode, and you walk towards a block while trying to break the block with a sword, you walk faltering. You stop lagging as soon as you stop walking or breaking the block.
How te reproduce
build some sort of wall(in my case of stone bricks)
go to creative mode
take a sword(in my case a diamond sword)
hold the left mouse button down pointing at the wall
walk towards the block and you will start lagging
Thank you for your report!
We're actually already tracking this issue in MC-157436, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
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