--- a/src/toolsets/algorithmtoolset.cpp Sat Mar 03 17:59:56 2018 +0200 +++ b/src/toolsets/algorithmtoolset.cpp Mon Mar 05 22:40:34 2018 +0200 @@ -69,8 +69,10 @@ // │ │ --→ │ ╱ ╱ │ // │ │ --→ │╱ ╱ │ // 1───2 1 1───2 - LDTriangle* triangle1 = currentDocument()->emplaceReplacementAt<LDTriangle>(index.row(), v0, v1, v3); - LDTriangle* triangle2 = currentDocument()->emplaceAt<LDTriangle>(index.row() + 1, v1, v2, v3); + int row = index.row(); + currentDocument()->removeAt(index); + LDTriangle* triangle1 = currentDocument()->emplaceAt<LDTriangle>(row, v0, v1, v3); + LDTriangle* triangle2 = currentDocument()->emplaceAt<LDTriangle>(row + 1, v1, v2, v3); // The triangles also inherit the quad's color triangle1->setColor(color);