Fix #32355: select vertex path not working when vertices are selected with e.g.

border select. There was a fix before bmesh where it would require exactly two
vertices to be selected, but this was not ported over, and it also wasn't quite
correct.

This case should also work: click on two vertices, selected the path between
them, and then click on a 3rd vertex and select path, to extend the path further
from the 2nd to the 3rd vertex.

Now both use cases should work.

1 files changed, 32 insertions, 6 deletions

diff --git a/source/blender/editors/mesh/editmesh_tools.c b/source/blender/editors/mesh/editmesh_tools.c
index 4b8edb920a1..3de945fb06c 100644
--- a/source/blender/editors/mesh/editmesh_tools.c
+++ b/source/blender/editors/mesh/editmesh_tools.c
@@ -2122,23 +2122,49 @@ static int edbm_select_vertex_path_exec(bContext *C, wmOperator *op)
 	Object *ob = CTX_data_edit_object(C);
 	BMEditMesh *em = BMEdit_FromObject(ob);
 	BMOperator bmop;
+	BMIter iter;
+	BMVert *eve = NULL, *svert = NULL, *evert = NULL;
 	BMEditSelection *sv, *ev;
 
 	/* get the type from RNA */
 	int type = RNA_enum_get(op->ptr, "type");
 
+	/* first try to find vertices in edit selection */
 	sv = em->bm->selected.last;
-	if (sv != NULL)
+	if (sv != NULL) {
 		ev = sv->prev;
-	else return OPERATOR_CANCELLED;
-	if (ev == NULL)
-		return OPERATOR_CANCELLED;
 
-	if ((sv->htype != BM_VERT) || (ev->htype != BM_VERT))
+		if (ev && (sv->htype == BM_VERT) && (ev->htype == BM_VERT)) {
+			svert = (BMVert *)sv->ele;
+			evert = (BMVert *)ev->ele;
+		}
+	}
+
+	/* if those are not found, because vertices where selected by e.g.
+	   border or circle select, find two selected vertices */
+	if (svert == NULL) {
+		BM_ITER_MESH (eve, &iter, em->bm, BM_VERTS_OF_MESH) {
+			if (!BM_elem_flag_test(eve, BM_ELEM_SELECT) || BM_elem_flag_test(eve, BM_ELEM_HIDDEN))
+				continue;
+
+			if (svert == NULL) svert = eve;
+			else if (evert == NULL) evert = eve;
+			else {
+				/* more than two vertices are selected,
+				   show warning message and cancel operator */
+				svert = evert = NULL;
+				break;
+			}
+		}
+	}
+
+	if (svert == NULL || evert == NULL) {
+		BKE_report(op->reports, RPT_WARNING, "Path Selection requires that two vertices be selected");
 		return OPERATOR_CANCELLED;
+	}
 
 	/* initialize the bmop using EDBM api, which does various ui error reporting and other stuff */
-	EDBM_op_init(em, &bmop, op, "shortest_path startv=%e endv=%e type=%i", sv->ele, ev->ele, type);
+	EDBM_op_init(em, &bmop, op, "shortest_path startv=%e endv=%e type=%i", svert, evert, type);
 
 	/* execute the operator */
 	BMO_op_exec(em->bm, &bmop);