Partial fix for array modifier vertex merge (bug 30195).

Two fixes:

* The find-doubles operator was overriding the "dirty" element
  indices, so vertices were not being mapped correctly.

* In some cases a vertex can be set to merge with a vertex that is
  also set to be merged, so added a loop to find the first unmerged
  vert in this case.

Not yet working is the "First Last" merge option.

Also made some cleanups and added comments in the array/remove doubles
code.

1 files changed, 6 insertions, 1 deletions

diff --git a/source/blender/bmesh/operators/bmo_removedoubles.c b/source/blender/bmesh/operators/bmo_removedoubles.c
index a5e4cd31f41..5bf40e6fd38 100644
--- a/source/blender/bmesh/operators/bmo_removedoubles.c
+++ b/source/blender/bmesh/operators/bmo_removedoubles.c
@@ -103,6 +103,7 @@ void bmo_weldverts_exec(BMesh *bm, BMOperator *op)
 	BMFace *f, *f2;
 	int a, b;
 
+	/* mark merge verts for deletion */
 	BM_ITER(v, &iter, bm, BM_VERTS_OF_MESH, NULL) {
 		if ((v2 = BMO_slot_map_ptr_get(bm, op, "targetmap", v))) {
 			BMO_elem_flag_enable(bm, v, ELE_DEL);
@@ -112,10 +113,12 @@ void bmo_weldverts_exec(BMesh *bm, BMOperator *op)
 		}
 	}
 
+	/* check if any faces are getting their own corners merged
+	   together, split face if so */
 	BM_ITER(f, &iter, bm, BM_FACES_OF_MESH, NULL) {
 		remdoubles_splitface(f, bm, op);
 	}
-	
+
 	BM_ITER(e, &iter, bm, BM_EDGES_OF_MESH, NULL) {
 		if (BMO_elem_flag_test(bm, e->v1, ELE_DEL) || BMO_elem_flag_test(bm, e->v2, ELE_DEL)) {
 			v = BMO_slot_map_ptr_get(bm, op, "targetmap", e->v1);
@@ -149,6 +152,8 @@ void bmo_weldverts_exec(BMesh *bm, BMOperator *op)
 	}
 	bm->elem_index_dirty |= BM_FACE;
 
+	/* faces get "modified" by creating new faces here, then at the
+	   end the old faces are deleted */
 	BM_ITER(f, &iter, bm, BM_FACES_OF_MESH, NULL) {
 		if (!BMO_elem_flag_test(bm, f, FACE_MARK))
 			continue;