"Fix" for #17636 Crashing bug - won't open a file

- The cause was indeed corrupted particle settings which should have caused a deletion of the whole particle system. However the particle modifier was still left and that led to the crash.
- A "fix" because there's really no way of knowing what caused the corruption of the particle settings. If anyone else gets this and can recreate I'd love to get a .blend. Now that there shouldn't be a crash anymore the symptom will be a missing particle system after file load in an object that had a particle system before.

3 files changed, 12 insertions, 4 deletions

diff --git a/source/blender/blenkernel/intern/depsgraph.c b/source/blender/blenkernel/intern/depsgraph.c
index 1be0a2aafdb..d958c43aa40 100644
--- a/source/blender/blenkernel/intern/depsgraph.c
+++ b/source/blender/blenkernel/intern/depsgraph.c
@@ -581,9 +581,12 @@ static void build_dag_object(DagForest *dag, DagNode *scenenode, Object *ob, int
 
 		for(; psys; psys=psys->next) {
 			ParticleSettings *part= psys->part;
-			
+
 			dag_add_relation(dag, node, node, DAG_RL_OB_DATA, "Particle-Object Relation");
 
+			if(psys->flag & PSYS_DISABLED || psys->flag & PSYS_DELETE)
+				continue;
+
 			if(part->phystype==PART_PHYS_KEYED && psys->keyed_ob &&
 			   BLI_findlink(&psys->keyed_ob->particlesystem,psys->keyed_psys-1)) {
 				node2 = dag_get_node(dag, psys->keyed_ob);
diff --git a/source/blender/blenkernel/intern/particle.c b/source/blender/blenkernel/intern/particle.c
index 2678608fb9a..c9d16c0017f 100644
--- a/source/blender/blenkernel/intern/particle.c
+++ b/source/blender/blenkernel/intern/particle.c
@@ -296,7 +296,7 @@ int psys_check_enabled(Object *ob, ParticleSystem *psys)
 	ParticleSystemModifierData *psmd;
 	Mesh *me;
 
-	if(psys->flag & PSYS_DISABLED)
+	if(psys->flag & PSYS_DISABLED || psys->flag & PSYS_DELETE)
 		return 0;
 
 	if(ob->type == OB_MESH) {
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 8865e3bb173..6add88284c2 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -2596,7 +2596,7 @@ static void direct_link_particlesettings(FileData *fd, ParticleSettings *part)
 	part->pd2= newdataadr(fd, part->pd2);
 }
 
-static void lib_link_particlesystems(FileData *fd, ID *id, ListBase *particles)
+static void lib_link_particlesystems(FileData *fd, Object *ob, ID *id, ListBase *particles)
 {
 	ParticleSystem *psys, *psysnext;
 	int a;
@@ -2616,6 +2616,11 @@ static void lib_link_particlesystems(FileData *fd, ID *id, ListBase *particles)
 			}
 		}
 		else {
+			/* particle modifier must be removed before particle system */
+			ParticleSystemModifierData *psmd= psys_get_modifier(ob,psys);
+			BLI_remlink(&ob->modifiers, psmd);
+			modifier_free((ModifierData *)psmd);
+
 			BLI_remlink(particles, psys);
 			MEM_freeN(psys);
 		}
@@ -3069,7 +3074,7 @@ static void lib_link_object(FileData *fd, Main *main)
 					ob->pd->tex=newlibadr_us(fd, ob->id.lib, ob->pd->tex);
 
 			lib_link_scriptlink(fd, &ob->id, &ob->scriptlink);
-			lib_link_particlesystems(fd, &ob->id, &ob->particlesystem);
+			lib_link_particlesystems(fd, ob, &ob->id, &ob->particlesystem);
 			lib_link_modifiers(fd, ob);
 		}
 		ob= ob->id.next;