From: bones_was_here <bones_was_here@xonotic.au>
Date: Wed, 13 Sep 2023 20:30:31 +0000 (+1000)
Subject: SV_FlyMove(): defer SV_Impact() call until after ground detection
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=e62e6f563b475060fca315b875aa672c692ad052;p=xonotic%2Fdarkplaces.git

SV_FlyMove(): defer SV_Impact() call until after ground detection

Quake didn't use SV_PushEntity in SV_FlyMove() and id1 fiends depend on
the original behaviour of setting ONGROUND (etc) before calling
SV_Impact().
Fixes https://github.com/DarkPlacesEngine/darkplaces/issues/94

Signed-off-by: bones_was_here <bones_was_here@xonotic.au>
---

diff --git a/sv_phys.c b/sv_phys.c
index 8a4d41df..e9cc1914 100644
--- a/sv_phys.c
+++ b/sv_phys.c
@@ -1332,6 +1332,14 @@ static int SV_FlyMove (prvm_edict_t *ent, float time, qbool applygravity, float
 			if (stepnormal)
 				VectorCopy(trace.plane.normal, stepnormal);
 		}
+
+		// Unlike some other movetypes Quake's SV_FlyMove calls SV_Impact only after setting ONGROUND which id1 fiends rely on.
+		// If we stepped up (sv_gameplayfix_stepmultipletimes) this will impact the steptrace2 plane instead of the original.
+		if (PRVM_serveredictfloat(ent, solid) >= SOLID_TRIGGER && trace.ent)
+			SV_Impact(ent, &trace);
+		if (ent->free)
+			return blocked; // removed by the impact function
+
 		if (trace.fraction >= 0.001)
 		{
 			// actually covered some distance
@@ -1627,10 +1635,12 @@ static qbool SV_PushEntity (trace_t *trace, prvm_edict_t *ent, vec3_t push, qboo
 #endif
 
 	if (dolink)
+	{
 		SV_LinkEdict_TouchAreaGrid(ent);
 
-	if((PRVM_serveredictfloat(ent, solid) >= SOLID_TRIGGER && trace->ent && (!((int)PRVM_serveredictfloat(ent, flags) & FL_ONGROUND) || PRVM_serveredictedict(ent, groundentity) != PRVM_EDICT_TO_PROG(trace->ent))))
-		SV_Impact (ent, trace);
+		if((PRVM_serveredictfloat(ent, solid) >= SOLID_TRIGGER && trace->ent && (!((int)PRVM_serveredictfloat(ent, flags) & FL_ONGROUND) || PRVM_serveredictedict(ent, groundentity) != PRVM_EDICT_TO_PROG(trace->ent))))
+			SV_Impact (ent, trace);
+	}
 
 	if(ent->priv.required->mark == PRVM_EDICT_MARK_SETORIGIN_CAUGHT)
 	{