Fix bad pointer cast when modifier is used on non-mesh object

source/blender/modifiers/intern/MOD_armature.c

@@ -135,11 +135,7 @@ static void deformVertsEM(
         Mesh *mesh, float (*vertexCos)[3], int numVerts)
 {
 	ArmatureModifierData *amd = (ArmatureModifierData *) md;
-	Mesh *mesh_src = mesh;
+	Mesh *mesh_src = get_mesh(ctx->object, em, mesh, NULL, false, false);
-
-	if (!mesh) {
-		mesh_src = BKE_bmesh_to_mesh_nomain(em->bm, &(struct BMeshToMeshParams){0});
-	}
 
 	modifier_vgroup_cache(md, vertexCos); /* if next modifier needs original vertices */
 
@@ -152,7 +148,7 @@ static void deformVertsEM(
 		amd->prevCos = NULL;
 	}
 
-	if (!mesh) {
+	if (mesh_src != mesh) {
 		BKE_id_free(NULL, mesh_src);
 	}
 }
@@ -163,16 +159,12 @@ static void deformMatricesEM(
         float (*defMats)[3][3], int numVerts)
 {
 	ArmatureModifierData *amd = (ArmatureModifierData *) md;
-	Mesh *mesh_src = mesh;
+	Mesh *mesh_src = get_mesh(ctx->object, em, mesh, NULL, false, false);
-
-	if (!mesh) {
-		mesh_src = BKE_bmesh_to_mesh_nomain(em->bm, &(struct BMeshToMeshParams){0});
-	}
 
 	armature_deform_verts(amd->object, ctx->object, mesh_src, vertexCos, defMats, numVerts,
 	                      amd->deformflag, NULL, amd->defgrp_name);
 
-	if (!mesh) {
+	if (mesh_src != mesh) {
 		BKE_id_free(NULL, mesh_src);
 	}
 }
@@ -181,10 +173,14 @@ static void deformMatrices(ModifierData *md, const ModifierEvalContext *ctx, Mes
                            float (*vertexCos)[3], float (*defMats)[3][3], int numVerts)
 {
 	ArmatureModifierData *amd = (ArmatureModifierData *) md;
-	Mesh *mesh_src = mesh ? mesh : ctx->object->data;
+	Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);
 
 	armature_deform_verts(amd->object, ctx->object, mesh_src, vertexCos, defMats, numVerts,
 	                      amd->deformflag, NULL, amd->defgrp_name);
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}
 }
 
 ModifierTypeInfo modifierType_Armature = {

source/blender/modifiers/intern/MOD_cast.c

@@ -428,12 +428,7 @@ static void deformVerts(ModifierData *md, const ModifierEvalContext *ctx,
                         int numVerts)
 {
 	CastModifierData *cmd = (CastModifierData *)md;
-
+	Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);
-	Mesh *mesh_src = mesh;
-
-	if (mesh_src == NULL) {
-		mesh_src = ctx->object->data;
-	}
 
 	BLI_assert(mesh_src->totvert == numVerts);
 
@@ -443,6 +438,10 @@ static void deformVerts(ModifierData *md, const ModifierEvalContext *ctx,
 	else { /* MOD_CAST_TYPE_SPHERE or MOD_CAST_TYPE_CYLINDER */
 		sphere_do(cmd, ctx->object, mesh_src, vertexCos, numVerts);
 	}
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}
 }
 
 static void deformVertsEM(
@@ -451,12 +450,7 @@ static void deformVertsEM(
         Mesh *mesh, float (*vertexCos)[3], int numVerts)
 {
 	CastModifierData *cmd = (CastModifierData *)md;
-
+	Mesh *mesh_src = get_mesh(ctx->object, editData, mesh, NULL, false, false);
-	Mesh *mesh_src = mesh;
-
-	if (mesh_src == NULL) {
-		mesh_src = BKE_bmesh_to_mesh_nomain(editData->bm, &(struct BMeshToMeshParams){0});
-	}
 
 	BLI_assert(mesh_src->totvert == numVerts);
 
@@ -467,7 +461,7 @@ static void deformVertsEM(
 		sphere_do(cmd, ctx->object, mesh_src, vertexCos, numVerts);
 	}
 
-	if (!mesh) {
+	if (mesh_src != mesh) {
 		BKE_id_free(NULL, mesh_src);
 	}
 }

source/blender/modifiers/intern/MOD_curve.c

@@ -51,6 +51,7 @@
 #include "DEG_depsgraph_build.h"
 
 #include "MOD_modifiertypes.h"
+#include "MOD_util.h"
 
 static void initData(ModifierData *md)
 {
@@ -112,18 +113,17 @@ static void deformVerts(
         int numVerts)
 {
 	CurveModifierData *cmd = (CurveModifierData *) md;
-
+	Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);
-	Mesh *mesh_src = mesh;
-
-	if (mesh_src == NULL) {
-		mesh_src = ctx->object->data;
-	}
 
 	BLI_assert(mesh_src->totvert == numVerts);
 
 	/* silly that defaxis and curve_deform_verts are off by 1
 	 * but leave for now to save having to call do_versions */
 	curve_deform_verts(cmd->object, ctx->object, mesh_src, vertexCos, numVerts, cmd->name, cmd->defaxis - 1);
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}
 }
 
 static void deformVertsEM(
@@ -134,17 +134,13 @@ static void deformVertsEM(
         float (*vertexCos)[3],
         int numVerts)
 {
-	Mesh *mesh_src = mesh;
+	Mesh *mesh_src = get_mesh(ctx->object, em, mesh, NULL, false, false);
-
-	if (mesh_src == NULL) {
-		mesh_src = BKE_bmesh_to_mesh_nomain(em->bm, &(struct BMeshToMeshParams){0});
-	}
 
 	BLI_assert(mesh_src->totvert == numVerts);
 
 	deformVerts(md, ctx, mesh_src, vertexCos, numVerts);
 
-	if (!mesh) {
+	if (mesh_src != mesh) {
 		BKE_id_free(NULL, mesh_src);
 	}
 }

source/blender/modifiers/intern/MOD_displace.c

@@ -367,33 +367,29 @@ static void deformVerts(
         float (*vertexCos)[3],
         int numVerts)
 {
-	Mesh *mesh_src = mesh;
+	Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);
-
-	if (mesh_src == NULL) {
-		mesh_src = ctx->object->data;
-	}
 
 	BLI_assert(mesh_src->totvert == numVerts);
 
 	displaceModifier_do((DisplaceModifierData *)md, ctx->object, mesh_src,
 	                    vertexCos, numVerts);
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}
 }
 
 static void deformVertsEM(
         ModifierData *md, const ModifierEvalContext *ctx, struct BMEditMesh *editData,
         Mesh *mesh, float (*vertexCos)[3], int numVerts)
 {
-	Mesh *mesh_src = mesh;
+	Mesh *mesh_src = get_mesh(ctx->object, editData, mesh, NULL, false, false);
-
-	if (mesh_src == NULL) {
-		mesh_src = BKE_bmesh_to_mesh_nomain(editData->bm, &(struct BMeshToMeshParams){0});
-	}
 
 	BLI_assert(mesh_src->totvert == numVerts);
 
 	displaceModifier_do((DisplaceModifierData *)md, ctx->object, mesh_src, vertexCos, numVerts);
 
-	if (!mesh) {
+	if (mesh_src != mesh) {
 		BKE_id_free(NULL, mesh_src);
 	}
 }

source/blender/modifiers/intern/MOD_hook.c

@@ -352,9 +352,13 @@ static void deformVerts(struct ModifierData *md, const struct ModifierEvalContex
                         float (*vertexCos)[3], int numVerts)
 {
 	HookModifierData *hmd = (HookModifierData *)md;
-	Mesh *mesh_src = mesh ? mesh : ctx->object->data;
+	Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);
 
 	deformVerts_do(hmd, ctx->object, mesh_src, vertexCos, numVerts);
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}
 }
 
 static void deformVertsEM(struct ModifierData *md, const struct ModifierEvalContext *ctx,
@@ -362,10 +366,7 @@ static void deformVertsEM(struct ModifierData *md, const struct ModifierEvalCont
                           struct Mesh *mesh, float (*vertexCos)[3], int numVerts)
 {
 	HookModifierData *hmd = (HookModifierData *)md;
-	Mesh *mesh_src = mesh;
+	Mesh *mesh_src = get_mesh(ctx->object, editData, mesh, NULL, false, false);
-	if (!mesh) {
-		mesh_src = BKE_bmesh_to_mesh_nomain(editData->bm, &(struct BMeshToMeshParams){0});
-	}
 
 	deformVerts_do(hmd, ctx->object, mesh_src, vertexCos, numVerts);
 

source/blender/modifiers/intern/MOD_lattice.c

@@ -99,27 +99,26 @@ static void deformVerts(ModifierData *md, const ModifierEvalContext *ctx,
                         int numVerts)
 {
 	LatticeModifierData *lmd = (LatticeModifierData *) md;
-	struct Mesh *mesh_src = mesh ? mesh : ctx->object->data;
+	struct Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);
 
 	modifier_vgroup_cache(md, vertexCos); /* if next modifier needs original vertices */
 
 	lattice_deform_verts(lmd->object, ctx->object, mesh_src,
 	                     vertexCos, numVerts, lmd->name, lmd->strength);
-}
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}}
 
 static void deformVertsEM(
         ModifierData *md, const ModifierEvalContext *ctx, struct BMEditMesh *em,
         struct Mesh *mesh, float (*vertexCos)[3], int numVerts)
 {
-	struct Mesh *mesh_src = mesh;
+	struct Mesh *mesh_src = get_mesh(ctx->object, em, mesh, NULL, false, false);
-
-	if (!mesh) {
-		mesh_src = BKE_bmesh_to_mesh_nomain(em->bm, &(struct BMeshToMeshParams){0});
-	}
 
 	deformVerts(md, ctx, mesh_src, vertexCos, numVerts);
 
-	if (!mesh) {
+	if (mesh_src != mesh) {
 		BKE_id_free(NULL, mesh_src);
 	}
 }

source/blender/modifiers/intern/MOD_simpledeform.c

@@ -42,6 +42,7 @@
 #include "BKE_cdderivedmesh.h"
 #include "BKE_editmesh.h"
 #include "BKE_mesh.h"
+#include "BKE_library.h"
 #include "BKE_library_query.h"
 #include "BKE_modifier.h"
 #include "BKE_deform.h"
@@ -383,8 +384,13 @@ static void deformVerts(ModifierData *md, const ModifierEvalContext *ctx,
                         float (*vertexCos)[3],
                         int numVerts)
 {
-	Mesh *mesh_src = mesh ? mesh : ctx->object->data;
+	Mesh *mesh_src = get_mesh(ctx->object, NULL, mesh, NULL, false, false);
+
 	SimpleDeformModifier_do((SimpleDeformModifierData *)md, ctx->object, mesh_src, vertexCos, numVerts);
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}
 }
 
 static void deformVertsEM(ModifierData *md, const ModifierEvalContext *ctx,
@@ -393,11 +399,13 @@ static void deformVertsEM(ModifierData *md, const ModifierEvalContext *ctx,
                           float (*vertexCos)[3],
                           int numVerts)
 {
-	Mesh *mesh_src = mesh;
+	Mesh *mesh_src = get_mesh(ctx->object, editData, mesh, NULL, false, false);
-	if (!mesh) {
+
-		mesh_src = BKE_bmesh_to_mesh_nomain(editData->bm, &(struct BMeshToMeshParams){0});
-	}
 	SimpleDeformModifier_do((SimpleDeformModifierData *)md, ctx->object, mesh_src, vertexCos, numVerts);
+
+	if (mesh_src != mesh) {
+		BKE_id_free(NULL, mesh_src);
+	}
 }
 
 

source/blender/modifiers/intern/MOD_util.c

@@ -300,6 +300,8 @@ Mesh *get_mesh(Object *ob, struct BMEditMesh *em, Mesh *mesh,
 		struct BMeshToMeshParams bmtmp = {0};
 		if (em) mesh = BKE_bmesh_to_mesh_nomain(em->bm, &bmtmp);
 		else {
+			/* TODO(sybren): after modifier conversion of DM to Mesh is done, check whether
+			 * we really need a copy here. Maybe the CoW ob->data can be directly used. */
 			BKE_id_copy_ex(
 			        NULL, ob->data, (ID **)&mesh,
 			        LIB_ID_CREATE_NO_MAIN |
@@ -308,6 +310,8 @@ Mesh *get_mesh(Object *ob, struct BMEditMesh *em, Mesh *mesh,
 			        false);
 		}
 
+		/* TODO(sybren): after modifier conversion of DM to Mesh is done, check whether
+		 * we really need vertexCos here. */
 		if (vertexCos) {
 			BKE_mesh_apply_vert_coords(mesh, vertexCos);
 			mesh->runtime.cd_dirty_vert |= CD_MASK_NORMAL;