Data Transfer Modifier: fix mesh_get_eval_final usage.

It can't be used during modifier evaluation, and rna
enum code should access the evaluated objects.

3 files changed, 23 insertions, 5 deletions

diff --git a/source/blender/blenkernel/intern/data_transfer.c b/source/blender/blenkernel/intern/data_transfer.c
index 73c5f6cecdf..7ac9d2d985c 100644
--- a/source/blender/blenkernel/intern/data_transfer.c
+++ b/source/blender/blenkernel/intern/data_transfer.c
@@ -1087,6 +1087,7 @@ bool BKE_object_data_transfer_ex(
 	bool geom_map_init[DATAMAX] = {0};
 	ListBase lay_map = {NULL};
 	bool changed = false;
+	bool is_modifier = false;
 
 	const bool use_delete = false;  /* We never delete data layers from destination here. */
 
@@ -1099,6 +1100,7 @@ bool BKE_object_data_transfer_ex(
 		/* Never create needed custom layers on passed destination mesh
 		 * (assumed to *not* be ob_dst->data, aka modifier case). */
 		use_create = false;
+		is_modifier = true;
 	}
 	else {
 		me_dst = ob_dst->data;
@@ -1113,7 +1115,17 @@ bool BKE_object_data_transfer_ex(
 
 	/* Get source evaluated mesh.*/
 	me_src_mask |= BKE_object_data_transfer_dttypes_to_cdmask(data_types);
-	me_src = mesh_get_eval_final(depsgraph, scene, ob_src, me_src_mask);
+	if (is_modifier) {
+		me_src = ob_src->runtime.mesh_eval;
+
+		if (me_src == NULL || (me_src_mask & ~ob_src->lastDataMask) != 0) {
+			printf("Data Transfer: source mesh data is not ready - dependency cycle?\n");
+			return changed;
+		}
+	}
+	else {
+		me_src = mesh_get_eval_final(depsgraph, scene, ob_src, me_src_mask);
+	}
 	if (!me_src) {
 		return changed;
 	}
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index aa35f6e3278..5e69f8a32f3 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -312,6 +312,7 @@ const EnumPropertyItem rna_enum_axis_flag_xyz_items[] = {
 
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_build.h"
+#include "DEG_depsgraph_query.h"
 
 #ifdef WITH_ALEMBIC
 #  include "ABC_alembic.h"
@@ -902,7 +903,6 @@ static const EnumPropertyItem *rna_DataTransferModifier_layers_select_src_itemf(
 	}
 
 	Depsgraph *depsgraph = CTX_data_depsgraph(C);
-	Scene *scene = CTX_data_scene(C);
 
 	/* No active here! */
 	RNA_enum_items_add_value(&item, &totitem, rna_enum_dt_layers_select_src_items, DT_LAYERS_ALL_SRC);
@@ -940,7 +940,10 @@ static const EnumPropertyItem *rna_DataTransferModifier_layers_select_src_itemf(
 			Mesh *me_eval;
 			int num_data, i;
 
-			me_eval = mesh_get_eval_final(depsgraph, scene, ob_src, CD_MASK_BAREMESH | CD_MLOOPUV);
+			Scene *scene_eval = DEG_get_evaluated_scene(depsgraph);
+			Object *ob_src_eval = DEG_get_evaluated_object(depsgraph, ob_src);
+
+			me_eval = mesh_get_eval_final(depsgraph, scene_eval, ob_src_eval, CD_MASK_BAREMESH | CD_MLOOPUV);
 			num_data = CustomData_number_of_layers(&me_eval->ldata, CD_MLOOPUV);
 
 			RNA_enum_item_add_separator(&item, &totitem);
@@ -959,7 +962,10 @@ static const EnumPropertyItem *rna_DataTransferModifier_layers_select_src_itemf(
 			Mesh *me_eval;
 			int num_data, i;
 
-			me_eval = mesh_get_eval_final(depsgraph, scene, ob_src, CD_MASK_BAREMESH | CD_MLOOPCOL);
+			Scene *scene_eval = DEG_get_evaluated_scene(depsgraph);
+			Object *ob_src_eval = DEG_get_evaluated_object(depsgraph, ob_src);
+
+			me_eval = mesh_get_eval_final(depsgraph, scene_eval, ob_src_eval, CD_MASK_BAREMESH | CD_MLOOPCOL);
 			num_data = CustomData_number_of_layers(&me_eval->ldata, CD_MLOOPCOL);
 
 			RNA_enum_item_add_separator(&item, &totitem);
diff --git a/source/blender/modifiers/intern/MOD_datatransfer.c b/source/blender/modifiers/intern/MOD_datatransfer.c
index d3c0dd783cc..b2cb82d6be3 100644
--- a/source/blender/modifiers/intern/MOD_datatransfer.c
+++ b/source/blender/modifiers/intern/MOD_datatransfer.c
@@ -176,7 +176,7 @@ static Mesh *applyModifier(ModifierData *md, const ModifierEvalContext *ctx, Mes
 		BLI_SPACE_TRANSFORM_SETUP(space_transform, ctx->object, dtmd->ob_source);
 	}
 
-	if ((result == me_mod || (me->mvert == result->mvert) || (me->medge == result->medge)) &&
+	if (((result == me) || (me->mvert == result->mvert) || (me->medge == result->medge)) &&
 	    (dtmd->data_types & DT_TYPES_AFFECT_MESH))
 	{
 		/* We need to duplicate data here, otherwise setting custom normals, edges' shaprness, etc., could