Fix connect-vertices failing for concave ngons

Also add:
- generic callback for bmesh elements.
- ability to pass an existing array to a bmesh operator.

10 files changed, 275 insertions, 84 deletions

diff --git a/source/blender/bmesh/CMakeLists.txt b/source/blender/bmesh/CMakeLists.txt
index 50d3ac30ddc..23737866bf2 100644
--- a/source/blender/bmesh/CMakeLists.txt
+++ b/source/blender/bmesh/CMakeLists.txt
@@ -74,6 +74,8 @@ set(SRC
 	operators/bmo_utils.c
 	operators/bmo_wireframe.c
 
+	intern/bmesh_callback_generic.c
+	intern/bmesh_callback_generic.h
 	intern/bmesh_construct.c
 	intern/bmesh_construct.h
 	intern/bmesh_core.c
diff --git a/source/blender/bmesh/bmesh.h b/source/blender/bmesh/bmesh.h
index 4efc6aa16f8..87b1818fa5d 100644
--- a/source/blender/bmesh/bmesh.h
+++ b/source/blender/bmesh/bmesh.h
@@ -243,6 +243,7 @@ extern "C" {
 #include "intern/bmesh_error.h"
 
 #include "intern/bmesh_core.h"
+#include "intern/bmesh_callback_generic.h"
 #include "intern/bmesh_construct.h"
 #include "intern/bmesh_delete.h"
 #include "intern/bmesh_edgeloop.h"
diff --git a/source/blender/bmesh/intern/bmesh_callback_generic.c b/source/blender/bmesh/intern/bmesh_callback_generic.c
new file mode 100644
index 00000000000..91fec392552
--- /dev/null
+++ b/source/blender/bmesh/intern/bmesh_callback_generic.c
@@ -0,0 +1,55 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/bmesh/intern/bmesh_callback_generic.c
+ *  \ingroup bmesh
+ *
+ * BM construction functions.
+ */
+
+#include "BLI_utildefines.h"
+
+#include "bmesh.h"
+
+#include "intern/bmesh_callback_generic.h"
+
+bool BM_elem_cb_check_hflag_ex(BMElem *ele, void *user_data)
+{
+	const unsigned int hflag_pair = GET_INT_FROM_POINTER(user_data);
+	const char hflag_p = (hflag_pair & 0xff);
+	const char hflag_n = (hflag_pair >> 8);
+
+	return ((BM_elem_flag_test(ele, hflag_p) != 0) &&
+	        (BM_elem_flag_test(ele, hflag_n) == 0));
+}
+
+bool BM_elem_cb_check_hflag_enabled(BMElem *ele, void *user_data)
+{
+	const char hflag = GET_INT_FROM_POINTER(user_data);
+
+	return (BM_elem_flag_test(ele, hflag) != 0);
+}
+
+bool BM_elem_cb_check_hflag_disabled(BMElem *ele, void *user_data)
+{
+	const char hflag = GET_INT_FROM_POINTER(user_data);
+
+	return (BM_elem_flag_test(ele, hflag) == 0);
+}
diff --git a/source/blender/bmesh/intern/bmesh_callback_generic.h b/source/blender/bmesh/intern/bmesh_callback_generic.h
new file mode 100644
index 00000000000..8c46128f3b0
--- /dev/null
+++ b/source/blender/bmesh/intern/bmesh_callback_generic.h
@@ -0,0 +1,44 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef __BMESH_CALLBACK_GENERIC_H__
+#define __BMESH_CALLBACK_GENERIC_H__
+
+/** \file blender/bmesh/intern/bmesh_callback_generic.h
+ *  \ingroup bmesh
+ */
+
+bool BM_elem_cb_check_hflag_enabled(BMElem *, void *user_data);
+bool BM_elem_cb_check_hflag_disabled(BMElem *, void *user_data);
+bool BM_elem_cb_check_hflag_ex(BMElem *, void *user_data);
+
+#define BM_elem_cb_check_hflag_ex_simple(type, hflag_p, hflag_n) \
+	(bool (*)(type, void *))BM_elem_cb_check_hflag_ex, \
+	SET_UINT_IN_POINTER(((hflag_p) | (hflag_n << 8)))
+
+#define BM_elem_cb_check_hflag_enabled_simple(type, hflag_p) \
+	(bool (*)(type, void *))BM_elem_cb_check_hflag_enabled, \
+	SET_UINT_IN_POINTER((hflag_p))
+
+#define BM_elem_cb_check_hflag_disabled_simple(type, hflag_n) \
+	(bool (*)(type, void *))BM_elem_cb_check_hflag_disabled, \
+	SET_UINT_IN_POINTER(hflag_n)
+
+#endif /* __BMESH_CALLBACK_GENERIC_H__ */
diff --git a/source/blender/bmesh/intern/bmesh_operator_api.h b/source/blender/bmesh/intern/bmesh_operator_api.h
index 287aafc8f9f..825bbb136b1 100644
--- a/source/blender/bmesh/intern/bmesh_operator_api.h
+++ b/source/blender/bmesh/intern/bmesh_operator_api.h
@@ -395,6 +395,8 @@ void BMO_slot_buffer_from_disabled_hflag(BMesh *bm, BMOperator *op,
                                          BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name,
                                          const char htype, const char hflag);
 
+void  BMO_slot_buffer_from_array(BMOperator *op, BMOpSlot *slot, BMHeader **ele_buffer, int ele_buffer_len);
+
 void  BMO_slot_buffer_from_single(BMOperator *op, BMOpSlot *slot, BMHeader *ele);
 void *BMO_slot_buffer_get_single(BMOpSlot *slot);
 
diff --git a/source/blender/bmesh/intern/bmesh_operators.c b/source/blender/bmesh/intern/bmesh_operators.c
index b041c010c22..ba154b04838 100644
--- a/source/blender/bmesh/intern/bmesh_operators.c
+++ b/source/blender/bmesh/intern/bmesh_operators.c
@@ -900,6 +900,21 @@ void BMO_slot_buffer_from_single(BMOperator *op, BMOpSlot *slot, BMHeader *ele)
 	*slot->data.buf = ele;
 }
 
+void BMO_slot_buffer_from_array(BMOperator *op, BMOpSlot *slot, BMHeader **ele_buffer, int ele_buffer_len)
+{
+	BMO_ASSERT_SLOT_IN_OP(slot, op);
+	BLI_assert(slot->slot_type == BMO_OP_SLOT_ELEMENT_BUF);
+	BLI_assert(slot->len == 0 || slot->len == ele_buffer_len);
+
+	if (slot->data.buf == NULL) {
+		slot->data.buf = BLI_memarena_alloc(op->arena, sizeof(*slot->data.buf) * ele_buffer_len);
+	}
+
+	slot->len = ele_buffer_len;
+	memcpy(slot->data.buf, ele_buffer, ele_buffer_len * sizeof(*slot->data.buf));
+}
+
+
 void *BMO_slot_buffer_get_single(BMOpSlot *slot)
 {
 	BLI_assert(slot->slot_type == BMO_OP_SLOT_ELEMENT_BUF);
@@ -1636,6 +1651,7 @@ static int BMO_opcode_from_opname_check(const char *opname)
  *
  * **Element Buffer** (#BMO_OP_SLOT_ELEMENT_BUF)
  * - `e` - single element vert/edge/face (use with #BMO_OP_SLOT_SUBTYPE_ELEM_IS_SINGLE).
+ * - `eb` - elem buffer, take an array and a length.
  * - `av` - all verts
  * - `ae` - all edges
  * - `af` - all faces
@@ -1756,12 +1772,23 @@ bool BMO_op_vinitf(BMesh *bm, BMOperator *op, const int flag, const char *_fmt,
 					state = true;
 					break;
 				}
-				case 'e':  /* single vert/edge/face */
+				case 'e':
 				{
-					BMHeader *ele = va_arg(vlist, void *);
 					BMOpSlot *slot = BMO_slot_get(op->slots_in, slot_name);
 
-					BMO_slot_buffer_from_single(op, slot, ele);
+					if (NEXT_CHAR(fmt) == 'b') {
+						BMHeader **ele_buffer = va_arg(vlist, void *);
+						int ele_buffer_len = va_arg(vlist, int);
+
+						BMO_slot_buffer_from_array(op, slot, ele_buffer, ele_buffer_len);
+						fmt++;
+					}
+					else {
+						/* single vert/edge/face */
+						BMHeader *ele = va_arg(vlist, void *);
+
+						BMO_slot_buffer_from_single(op, slot, ele);
+					}
 
 					state = true;
 					break;
diff --git a/source/blender/bmesh/intern/bmesh_queries.c b/source/blender/bmesh/intern/bmesh_queries.c
index f301108a6ae..ca40cf9e6c8 100644
--- a/source/blender/bmesh/intern/bmesh_queries.c
+++ b/source/blender/bmesh/intern/bmesh_queries.c
@@ -202,6 +202,26 @@ bool BM_vert_pair_share_face_check(
 	return false;
 }
 
+bool BM_vert_pair_share_face_check_cb(
+        BMVert *v_a, BMVert *v_b,
+        bool (*test_fn)(BMFace *, void *user_data), void *user_data)
+{
+	if (v_a->e && v_b->e) {
+		BMIter iter;
+		BMFace *f;
+
+		BM_ITER_ELEM (f, &iter, v_a, BM_FACES_OF_VERT) {
+			if (test_fn(f, user_data)) {
+				if (BM_vert_in_face(f, v_b)) {
+					return true;
+				}
+			}
+		}
+	}
+
+	return false;
+}
+
 /**
  * Given 2 verts, find the smallest face they share and give back both loops.
  */
diff --git a/source/blender/bmesh/intern/bmesh_queries.h b/source/blender/bmesh/intern/bmesh_queries.h
index 0d47633dc73..c8578a8b093 100644
--- a/source/blender/bmesh/intern/bmesh_queries.h
+++ b/source/blender/bmesh/intern/bmesh_queries.h
@@ -52,6 +52,9 @@ BMLoop *BM_vert_find_first_loop(BMVert *v) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(
 
 bool    BM_vert_pair_share_face_check(
         BMVert *v_a, BMVert *v_b) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
+bool    BM_vert_pair_share_face_check_cb(
+        BMVert *v_a, BMVert *v_b,
+        bool (*test_fn)(BMFace *f, void *user_data), void *user_data) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1, 2, 3);
 BMFace *BM_vert_pair_share_face_by_len(
         BMVert *v_a, BMVert *v_b,
         BMLoop **r_l_a, BMLoop **r_l_b,
diff --git a/source/blender/bmesh/operators/bmo_connect_pair.c b/source/blender/bmesh/operators/bmo_connect_pair.c
index cfffb6021cf..916ea3ebcd9 100644
--- a/source/blender/bmesh/operators/bmo_connect_pair.c
+++ b/source/blender/bmesh/operators/bmo_connect_pair.c
@@ -230,23 +230,45 @@ static PathLinkState *state_dupe_add(
 static PathLinkState *state_step__face_edges(
         PathContext *pc,
         PathLinkState *state, const PathLinkState *state_orig,
-        BMLoop *l_iter, BMLoop *l_last)
+        BMLoop *l_iter, BMLoop *l_last,
+        float *r_dist_best)
 {
+	BMLoop *l_iter_best = NULL;
+	float dist_best = *r_dist_best;
+
 	do {
 		if (state_isect_co_pair(pc, l_iter->v->co, l_iter->next->v->co)) {
-			BMElem *ele_next      = (BMElem *)l_iter->e;
-			BMElem *ele_next_from = (BMElem *)l_iter->f;
+			float dist_test;
+			float co_isect[3];
 
-			if (FACE_WALK_TEST((BMFace *)ele_next_from) &&
-			    (state_link_find(state, ele_next) == false))
-			{
-				if (state_orig->link_last != state->link_last) {
-					state = state_dupe_add(pc, state, state_orig);
+			state_calc_co_pair(pc, l_iter->v->co, l_iter->next->v->co, co_isect);
+			dist_test = len_squared_v3v3(state->co_prev, co_isect);
+			if (dist_test < dist_best) {
+				BMElem *ele_next      = (BMElem *)l_iter->e;
+				BMElem *ele_next_from = (BMElem *)l_iter->f;
+
+				if (FACE_WALK_TEST((BMFace *)ele_next_from) &&
+				    (state_link_find(state, ele_next) == false))
+				{
+					dist_best = dist_test;
+					l_iter_best = l_iter;
 				}
-				state_link_add(pc, state, ele_next, ele_next_from);
 			}
 		}
 	} while ((l_iter = l_iter->next) != l_last);
+
+	if ((l_iter = l_iter_best)) {
+		BMElem *ele_next      = (BMElem *)l_iter->e;
+		BMElem *ele_next_from = (BMElem *)l_iter->f;
+
+		if (state_orig->link_last != state->link_last) {
+			state = state_dupe_add(pc, state, state_orig);
+		}
+		state_link_add(pc, state, ele_next, ele_next_from);
+	}
+
+	*r_dist_best = dist_best;
+
 	return state;
 }
 
@@ -254,23 +276,40 @@ static PathLinkState *state_step__face_edges(
 static PathLinkState *state_step__face_verts(
         PathContext *pc,
         PathLinkState *state, const PathLinkState *state_orig,
-        BMLoop *l_iter, BMLoop *l_last)
+        BMLoop *l_iter, BMLoop *l_last, float *r_dist_best)
 {
+	BMLoop *l_iter_best = NULL;
+	float dist_best = *r_dist_best;
+
 	do {
 		if (state_isect_co_exact(pc, l_iter->v->co)) {
-			BMElem *ele_next      = (BMElem *)l_iter->v;
-			BMElem *ele_next_from = (BMElem *)l_iter->f;
+			const float dist_test = len_squared_v3v3(state->co_prev, l_iter->v->co);
+			if (dist_test < dist_best) {
+				BMElem *ele_next      = (BMElem *)l_iter->v;
+				BMElem *ele_next_from = (BMElem *)l_iter->f;
 
-			if (FACE_WALK_TEST((BMFace *)ele_next_from) &&
-			    state_link_find(state, ele_next) == false)
-			{
-				if (state_orig->link_last != state->link_last) {
-					state = state_dupe_add(pc, state, state_orig);
+				if (FACE_WALK_TEST((BMFace *)ele_next_from) &&
+				    state_link_find(state, ele_next) == false)
+				{
+					dist_best = dist_test;
+					l_iter_best = l_iter;
 				}
-				state_link_add(pc, state, ele_next, ele_next_from);
 			}
 		}
 	} while ((l_iter = l_iter->next) != l_last);
+
+	if ((l_iter = l_iter_best)) {
+		BMElem *ele_next      = (BMElem *)l_iter->v;
+		BMElem *ele_next_from = (BMElem *)l_iter->f;
+
+		if (state_orig->link_last != state->link_last) {
+			state = state_dupe_add(pc, state, state_orig);
+		}
+		state_link_add(pc, state, ele_next, ele_next_from);
+	}
+
+	*r_dist_best = dist_best;
+
 	return state;
 }
 
@@ -290,20 +329,12 @@ static bool state_step(PathContext *pc, PathLinkState *state)
 			if ((l_start->f != ele_from) &&
 			    FACE_WALK_TEST(l_start->f))
 			{
+				float dist_best = FLT_MAX;
 				/* very similar to block below */
-				if (BM_vert_in_face(l_start->f, pc->v_b)) {
-					if (state_orig.link_last != state->link_last) {
-						state = state_dupe_add(pc, state, &state_orig);
-					}
-
-					state_link_add(pc, state, (BMElem *)pc->v_b, (BMElem *)l_start->f);
-				}
-				else {
-					state = state_step__face_edges(pc, state, &state_orig,
-					                               l_start->next, l_start);
-					state = state_step__face_verts(pc, state, &state_orig,
-					                               l_start->next->next, l_start);
-				}
+				state = state_step__face_edges(pc, state, &state_orig,
+				                               l_start->next, l_start, &dist_best);
+				state = state_step__face_verts(pc, state, &state_orig,
+				                               l_start->next->next, l_start, &dist_best);
 			}
 		}
 	}
@@ -319,24 +350,14 @@ static bool state_step(PathContext *pc, PathLinkState *state)
 				if ((l_start->f != ele_from) &&
 				    FACE_WALK_TEST(l_start->f))
 				{
+					float dist_best = FLT_MAX;
 					/* very similar to block above */
-					if (BM_vert_in_face(l_start->f, pc->v_b)) {
-						BMElem *ele_next      = (BMElem *)pc->v_b;
-						BMElem *ele_next_from = (BMElem *)l_start->f;
-
-						if (state_orig.link_last != state->link_last) {
-							state = state_dupe_add(pc, state, &state_orig);
-						}
-						state_link_add(pc, state, ele_next, ele_next_from);
-					}
-					else {
-						state = state_step__face_edges(pc, state, &state_orig,
-						                               l_start->next, l_start->prev);
-						if (l_start->f->len > 3) {
-							/* adjacent verts are handled in state_step__vert_edges */
-							state = state_step__face_verts(pc, state, &state_orig,
-							                               l_start->next->next, l_start->prev);
-						}
+					state = state_step__face_edges(pc, state, &state_orig,
+					                               l_start->next, l_start->prev, &dist_best);
+					if (l_start->f->len > 3) {
+						/* adjacent verts are handled in state_step__vert_edges */
+						state = state_step__face_verts(pc, state, &state_orig,
+						                               l_start->next->next, l_start->prev, &dist_best);
 					}
 				}
 			}
@@ -351,31 +372,19 @@ static bool state_step(PathContext *pc, PathLinkState *state)
 				if (((BMElem *)e != ele_from) &&
 				    VERT_WALK_TEST(v_other))
 				{
-					if (v_other == pc->v_b) {
-						BMElem *ele_next      = (BMElem *)pc->v_b;
+					if (state_isect_co_exact(pc, v_other->co)) {
+						BMElem *ele_next      = (BMElem *)v_other;
 						BMElem *ele_next_from = (BMElem *)e;
-
-						if (state_orig.link_last != state->link_last) {
-							state = state_dupe_add(pc, state, &state_orig);
-						}
-						state_link_add(pc, state, ele_next, ele_next_from);
-					}
-					else {
-						if (state_isect_co_exact(pc, v_other->co)) {
-							BMElem *ele_next      = (BMElem *)v_other;
-							BMElem *ele_next_from = (BMElem *)e;
-							if (state_link_find(state, ele_next) == false) {
-								if (state_orig.link_last != state->link_last) {
-									state = state_dupe_add(pc, state, &state_orig);
-								}
-								state_link_add(pc, state, ele_next, ele_next_from);
+						if (state_link_find(state, ele_next) == false) {
+							if (state_orig.link_last != state->link_last) {
+								state = state_dupe_add(pc, state, &state_orig);
 							}
+							state_link_add(pc, state, ele_next, ele_next_from);
 						}
 					}
 				}
 			}
 		}
-
 	}
 	else {
 		BLI_assert(0);
@@ -562,12 +571,10 @@ void bmo_connect_vert_pair_exec(BMesh *bm, BMOperator *op)
 
 #if 1
 	if (found_all) {
-		/* leave 'check_degenerate' off, if a user tries to cut with 2 verts,
-		 * always connect even when resulting faces are degenerate [#39418] */
 		BMOperator op_sub;
 		BMO_op_initf(bm, &op_sub, 0,
-		             "connect_verts verts=%fv faces_exclude=%s",
-		             VERT_OUT, op, "faces_exclude");
+		             "connect_verts verts=%fv faces_exclude=%s check_degenerate=%b",
+		             VERT_OUT, op, "faces_exclude", true);
 		BMO_op_exec(bm, &op_sub);
 		BMO_slot_copy(&op_sub, slots_out, "edges.out",
 		              op,      slots_out, "edges.out");
diff --git a/source/blender/editors/mesh/editmesh_tools.c b/source/blender/editors/mesh/editmesh_tools.c
index 20c7f4eb521..4f4a7998a87 100644
--- a/source/blender/editors/mesh/editmesh_tools.c
+++ b/source/blender/editors/mesh/editmesh_tools.c
@@ -877,23 +877,50 @@ static int edbm_vert_connect_exec(bContext *C, wmOperator *op)
 	BMEditMesh *em = BKE_editmesh_from_object(obedit);
 	BMesh *bm = em->bm;
 	BMOperator bmop;
-	const bool is_pair = (bm->totvertsel == 2);
+	bool is_pair = (bm->totvertsel == 2);
 	int len;
-	
+	bool check_degenerate = true;
+	const int verts_len = bm->totvertsel;
+	BMVert **verts;
+
+
+	verts = MEM_mallocN(sizeof(*verts) * verts_len, __func__);
+	{
+		BMIter iter;
+		BMVert *v;
+		int i = 0;
+
+		BM_ITER_MESH (v, &iter, bm, BM_VERTS_OF_MESH) {
+			if (BM_elem_flag_test(v, BM_ELEM_SELECT)) {
+				verts[i++] = v;
+			}
+		}
+
+		if (is_pair) {
+			if (BM_vert_pair_share_face_check_cb(
+			        verts[0], verts[1],
+			        BM_elem_cb_check_hflag_disabled_simple(BMFace *, BM_ELEM_HIDDEN)))
+			{
+				check_degenerate = false;
+				is_pair = false;
+			}
+		}
+	}
+
 	if (is_pair) {
 		if (!EDBM_op_init(em, &bmop, op,
-		                  "connect_vert_pair verts=%hv verts_exclude=%hv faces_exclude=%hf",
-		                  BM_ELEM_SELECT, BM_ELEM_HIDDEN, BM_ELEM_HIDDEN))
+		                  "connect_vert_pair verts=%eb verts_exclude=%hv faces_exclude=%hf",
+		                  verts, verts_len, BM_ELEM_HIDDEN, BM_ELEM_HIDDEN))
 		{
-			return OPERATOR_CANCELLED;
+			goto finally;
 		}
 	}
 	else {
 		if (!EDBM_op_init(em, &bmop, op,
-		                  "connect_verts verts=%hv faces_exclude=%hf check_degenerate=%b",
-		                  BM_ELEM_SELECT, BM_ELEM_HIDDEN, true))
+		                  "connect_verts verts=%eb faces_exclude=%hf check_degenerate=%b",
+		                  verts, verts_len, BM_ELEM_HIDDEN, check_degenerate))
 		{
-			return OPERATOR_CANCELLED;
+			goto finally;
 		}
 	}
 
@@ -908,15 +935,18 @@ static int edbm_vert_connect_exec(bContext *C, wmOperator *op)
 	}
 
 	if (!EDBM_op_finish(em, &bmop, op, true)) {
-		return OPERATOR_CANCELLED;
+		len = 0;
 	}
 	else {
 		EDBM_selectmode_flush(em);  /* so newly created edges get the selection state from the vertex */
 
 		EDBM_update_generic(em, true, true);
-
-		return len ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 	}
+
+
+finally:
+	MEM_freeN(verts);
+	return len ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void MESH_OT_vert_connect(wmOperatorType *ot)