From ecf0c4b45a756039ccde6ffd1845c0232220952d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gustaf=20Alh=C3=A4ll?= <gustaf@hanicef.me>
Date: Fri, 7 Jul 2023 21:35:41 +0200
Subject: [PATCH] Fix segfault when calling P_RemoveMobj from MobjCollide hook
---
src/p_map.c | 214 ++++++++++++++++++++++++++--------------------------
1 file changed, 109 insertions(+), 105 deletions(-)
diff --git a/src/p_map.c b/src/p_map.c
index 0021fe450c..0221fbc11b 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -4005,131 +4005,135 @@ void P_BounceMove(mobj_t *mo)
slidemo = mo;
hitcount = 0;
-retry:
- if (++hitcount == 3)
- goto bounceback; // don't loop forever
-
- if (mo->player)
- {
- mmomx = mo->player->rmomx;
- mmomy = mo->player->rmomy;
- }
- else
+ do
{
- mmomx = mo->momx;
- mmomy = mo->momy;
- }
+ if (++hitcount == 3)
+ goto bounceback; // don't loop forever
- // trace along the three leading corners
- if (mo->momx > 0)
- {
- leadx = mo->x + mo->radius;
- trailx = mo->x - mo->radius;
- }
- else
- {
- leadx = mo->x - mo->radius;
- trailx = mo->x + mo->radius;
- }
+ if (mo->player)
+ {
+ mmomx = mo->player->rmomx;
+ mmomy = mo->player->rmomy;
+ }
+ else
+ {
+ mmomx = mo->momx;
+ mmomy = mo->momy;
+ }
- if (mo->momy > 0)
- {
- leady = mo->y + mo->radius;
- traily = mo->y - mo->radius;
- }
- else
- {
- leady = mo->y - mo->radius;
- traily = mo->y + mo->radius;
- }
+ // trace along the three leading corners
+ if (mo->momx > 0)
+ {
+ leadx = mo->x + mo->radius;
+ trailx = mo->x - mo->radius;
+ }
+ else
+ {
+ leadx = mo->x - mo->radius;
+ trailx = mo->x + mo->radius;
+ }
+
+ if (mo->momy > 0)
+ {
+ leady = mo->y + mo->radius;
+ traily = mo->y - mo->radius;
+ }
+ else
+ {
+ leady = mo->y - mo->radius;
+ traily = mo->y + mo->radius;
+ }
- bestslidefrac = FRACUNIT + 1;
+ bestslidefrac = FRACUNIT + 1;
- P_PathTraverse(leadx, leady, leadx + mmomx, leady + mmomy, PT_ADDLINES, PTR_SlideTraverse);
- P_PathTraverse(trailx, leady, trailx + mmomx, leady + mmomy, PT_ADDLINES, PTR_SlideTraverse);
- P_PathTraverse(leadx, traily, leadx + mmomx, traily + mmomy, PT_ADDLINES, PTR_SlideTraverse);
+ P_PathTraverse(leadx, leady, leadx + mmomx, leady + mmomy, PT_ADDLINES, PTR_SlideTraverse);
+ P_PathTraverse(trailx, leady, trailx + mmomx, leady + mmomy, PT_ADDLINES, PTR_SlideTraverse);
+ P_PathTraverse(leadx, traily, leadx + mmomx, traily + mmomy, PT_ADDLINES, PTR_SlideTraverse);
- // move up to the wall
- if (bestslidefrac == FRACUNIT + 1)
- {
- // the move must have hit the middle, so bounce straight back
-bounceback:
- if (P_TryMove(mo, mo->x - mmomx, mo->y - mmomy, true))
+ // move up to the wall
+ if (bestslidefrac == FRACUNIT + 1)
{
- mo->momx *= -1;
- mo->momy *= -1;
- mo->momx = FixedMul(mo->momx, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
- mo->momy = FixedMul(mo->momy, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
-
- if (mo->player)
+ // the move must have hit the middle, so bounce straight back
+bounceback:
+ if (P_TryMove(mo, mo->x - mmomx, mo->y - mmomy, true))
{
- mo->player->cmomx *= -1;
- mo->player->cmomy *= -1;
- mo->player->cmomx = FixedMul(mo->player->cmomx,
- (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
- mo->player->cmomy = FixedMul(mo->player->cmomy,
- (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
+ mo->momx *= -1;
+ mo->momy *= -1;
+ mo->momx = FixedMul(mo->momx, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
+ mo->momy = FixedMul(mo->momy, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
+
+ if (mo->player)
+ {
+ mo->player->cmomx *= -1;
+ mo->player->cmomy *= -1;
+ mo->player->cmomx = FixedMul(mo->player->cmomx,
+ (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
+ mo->player->cmomy = FixedMul(mo->player->cmomy,
+ (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
+ }
}
+ return;
}
- return;
- }
- // fudge a bit to make sure it doesn't hit
- bestslidefrac -= 0x800;
- if (bestslidefrac > 0)
- {
- newx = FixedMul(mmomx, bestslidefrac);
- newy = FixedMul(mmomy, bestslidefrac);
+ // fudge a bit to make sure it doesn't hit
+ bestslidefrac -= 0x800;
+ if (bestslidefrac > 0)
+ {
+ newx = FixedMul(mmomx, bestslidefrac);
+ newy = FixedMul(mmomy, bestslidefrac);
- if (!P_TryMove(mo, mo->x + newx, mo->y + newy, true))
- goto bounceback;
- }
+ if (!P_TryMove(mo, mo->x + newx, mo->y + newy, true))
+ {
+ if (P_MobjWasRemoved(mo))
+ return;
+ goto bounceback;
+ }
+ }
- // Now continue along the wall.
- // First calculate remainder.
- bestslidefrac = FRACUNIT - bestslidefrac;
+ // Now continue along the wall.
+ // First calculate remainder.
+ bestslidefrac = FRACUNIT - bestslidefrac;
- if (bestslidefrac > FRACUNIT)
- bestslidefrac = FRACUNIT;
+ if (bestslidefrac > FRACUNIT)
+ bestslidefrac = FRACUNIT;
- if (bestslidefrac <= 0)
- return;
+ if (bestslidefrac <= 0)
+ return;
- if (mo->type == MT_SHELL)
- {
- tmxmove = mmomx;
- tmymove = mmomy;
- }
- else if (mo->type == MT_THROWNBOUNCE)
- {
- tmxmove = FixedMul(mmomx, (FRACUNIT - (FRACUNIT>>6) - (FRACUNIT>>5)));
- tmymove = FixedMul(mmomy, (FRACUNIT - (FRACUNIT>>6) - (FRACUNIT>>5)));
- }
- else if (mo->type == MT_THROWNGRENADE || mo->type == MT_CYBRAKDEMON_NAPALM_BOMB_LARGE)
- {
- // Quickly decay speed as it bounces
- tmxmove = FixedDiv(mmomx, 2*FRACUNIT);
- tmymove = FixedDiv(mmomy, 2*FRACUNIT);
- }
- else
- {
- tmxmove = FixedMul(mmomx, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
- tmymove = FixedMul(mmomy, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
- }
+ if (mo->type == MT_SHELL)
+ {
+ tmxmove = mmomx;
+ tmymove = mmomy;
+ }
+ else if (mo->type == MT_THROWNBOUNCE)
+ {
+ tmxmove = FixedMul(mmomx, (FRACUNIT - (FRACUNIT>>6) - (FRACUNIT>>5)));
+ tmymove = FixedMul(mmomy, (FRACUNIT - (FRACUNIT>>6) - (FRACUNIT>>5)));
+ }
+ else if (mo->type == MT_THROWNGRENADE || mo->type == MT_CYBRAKDEMON_NAPALM_BOMB_LARGE)
+ {
+ // Quickly decay speed as it bounces
+ tmxmove = FixedDiv(mmomx, 2*FRACUNIT);
+ tmymove = FixedDiv(mmomy, 2*FRACUNIT);
+ }
+ else
+ {
+ tmxmove = FixedMul(mmomx, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
+ tmymove = FixedMul(mmomy, (FRACUNIT - (FRACUNIT>>2) - (FRACUNIT>>3)));
+ }
- P_HitBounceLine(bestslideline); // clip the moves
+ P_HitBounceLine(bestslideline); // clip the moves
- mo->momx = tmxmove;
- mo->momy = tmymove;
+ mo->momx = tmxmove;
+ mo->momy = tmymove;
- if (mo->player)
- {
- mo->player->cmomx = tmxmove;
- mo->player->cmomy = tmymove;
+ if (mo->player)
+ {
+ mo->player->cmomx = tmxmove;
+ mo->player->cmomy = tmymove;
+ }
}
-
- if (!P_TryMove(mo, mo->x + tmxmove, mo->y + tmymove, true))
- goto retry;
+ while (!P_TryMove(mo, mo->x + tmxmove, mo->y + tmymove, true) && !P_MobjWasRemoved(mo));
}
//
--
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