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  1. Minecraft: Java Edition
  2. MC-72028

Lightning occasionally deals damage twice

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Details

    • Bug
    • Status: Open
    • Resolution: Unresolved
    • Minecraft 1.7.10, Minecraft 1.8, Minecraft 1.8.1-pre2, Minecraft 1.8.1-pre5, Minecraft 1.8.1, Minecraft 1.8.7, Minecraft 15w46a, Minecraft 15w47a, Minecraft 15w47b, Minecraft 15w47c, Minecraft 1.9.4, Minecraft 16w20a, Minecraft 1.10.2, Minecraft 1.11, Minecraft 1.11.2, Minecraft 17w14a, Minecraft 17w17a, Minecraft 1.12 Pre-Release 2, Minecraft 1.12 Pre-Release 3, Minecraft 1.12 Pre-Release 5, Minecraft 1.12, Minecraft 1.12.1, Minecraft 1.12.2, Minecraft 17w43a, Minecraft 18w16a, Minecraft 18w21a, Minecraft 1.13-pre5, Minecraft 1.13, Minecraft 1.13.1, Minecraft 1.13.2, Minecraft 18w50a, Minecraft 1.14 Pre-Release 5, 1.14.4, 19w40a, 1.15 Pre-release 3, 1.16 Pre-release 1, 1.16.1, 1.16.2, 20w51a, 21w03a, 1.17, 1.17.1, 21w38a, 21w40a, 1.18 Release Candidate 1, 1.18, 1.18.1, 1.18.2, 22w14a, 22w18a, 1.19 Pre-release 1, 1.19
    • None
    • Confirmed
    • Entities
    • Normal

    Description

      The bug

      Lightning sometimes does damage multiple times, instead of only once (which would be the expected behavior).

      To reproduce

      • Summon a zombie pigman
      • Summon a Lightning bolt nearby with /summon minecraft:lightning_bolt
        The pigman will sometimes take damage twice.

      Code analysis

      Based on 1.11 decompiled using MCP 9.35 rc1

      Lightning bolts have two fields which are important for the following:

      • lightningState: Initialized to 2
      • boltLivingTime: Initialized to a random integer between 1 and 3 (both inclusive)

      Every time a lightning bolt is updated it does the following:

      1. Reduce lightningState by 1
      2. If lightningState < 0
        1. If boltLivingTime: Set dead
        2. Else if lightningState < random integer between -9 and 0 (both inclusive)
          1. Reduce boltLivingTime by 1
          2. Set lightningState to 1
      3. If lightningState >= 0: Deal damage to entities

      This means a lightning bolt can try to deal damage to entities up to 8 times with the last strike being in the 35th tick after the lightning bolt was created. This allows it to deal 20 damage to a player which would kill him.

      Attachments

        1. MC-72028.mp4
          3.78 MB
        2. MC-72028.png
          MC-72028.png
          2.96 MB

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              Unassigned Unassigned
              Sonicwave [Mod] Sonicwave
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              16 Vote for this issue
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              Dates

                Created:
                Updated:
                CHK: