From cf0bcebc7620ff2a4bfb44bcbc4909ff9dbe8d24 Mon Sep 17 00:00:00 2001 From: sfan5 Date: Fri, 2 Feb 2018 23:34:09 +0100 Subject: [PATCH] Refine movement anticheat again (#7004) * Account for walking speed in vertical dir * Avoid undefined behaviour due to division-by-zero --- src/content_sao.cpp | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/content_sao.cpp b/src/content_sao.cpp index 2b9d53665..247b6df0a 100644 --- a/src/content_sao.cpp +++ b/src/content_sao.cpp @@ -1414,6 +1414,12 @@ bool PlayerSAO::checkMovementCheat() // until this can be verified correctly, tolerate higher jumping speeds player_max_jump *= 2.0; + // Don't divide by zero! + if (player_max_walk < 0.0001f) + player_max_walk = 0.0001f; + if (player_max_jump < 0.0001f) + player_max_jump = 0.0001f; + v3f diff = (m_base_position - m_last_good_position); float d_vert = diff.Y; diff.Y = 0; @@ -1422,8 +1428,11 @@ bool PlayerSAO::checkMovementCheat() // FIXME: Checking downwards movement is not easily possible currently, // the server could calculate speed differences to examine the gravity - if (d_vert > 0) - required_time = MYMAX(required_time, d_vert / player_max_jump); + if (d_vert > 0) { + // In certain cases (water, ladders) walking speed is applied vertically + float s = MYMAX(player_max_jump, player_max_walk); + required_time = MYMAX(required_time, d_vert / s); + } if (m_move_pool.grab(required_time)) { m_last_good_position = m_base_position;