diff --git a/src/Gui/CMakeLists.txt b/src/Gui/CMakeLists.txt
index 706aba5e99..92838b4fa8 100644
--- a/src/Gui/CMakeLists.txt
+++ b/src/Gui/CMakeLists.txt
@@ -1118,6 +1118,7 @@ SET(FreeCADGui_CPP_SRCS
     GuiConsole.cpp
     Macro.cpp
     MergeDocuments.cpp
+    Namespace.h
     resource.cpp
     Control.cpp
     SpaceballEvent.cpp
diff --git a/src/Gui/GLPainter.h b/src/Gui/GLPainter.h
index 4a5acfdfbe..af69c24e31 100644
--- a/src/Gui/GLPainter.h
+++ b/src/Gui/GLPainter.h
@@ -25,7 +25,9 @@
 #define GUI_GLPAINTER_H
 
 #ifdef FC_OS_WIN32
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif
 #include <windows.h>
 #endif
 #ifdef FC_OS_MACOSX
diff --git a/src/Gui/MouseSelection.cpp b/src/Gui/MouseSelection.cpp
index 488304efcf..06c0c97f7f 100644
--- a/src/Gui/MouseSelection.cpp
+++ b/src/Gui/MouseSelection.cpp
@@ -51,7 +51,7 @@ AbstractMouseSelection::AbstractMouseSelection() : _pcView3D(0)
     m_iYold = 0;
     m_iXnew = 0;
     m_iYnew = 0;
-    m_bInner = true;
+    m_selectedRole = SelectionRole::None;
 }
 
 void AbstractMouseSelection::grabMouseModel(Gui::View3DInventorViewer* viewer)
@@ -434,6 +434,8 @@ int PolyPickerSelection::keyboardEvent(const SoKeyboardEvent* const)
 
 PolyClipSelection::PolyClipSelection()
 {
+    selectionBits.set(1);
+    selectionBits.set(2);
 }
 
 PolyClipSelection::~PolyClipSelection()
@@ -445,8 +447,13 @@ int PolyClipSelection::popupMenu()
     QMenu menu;
     QAction* ci = menu.addAction(QObject::tr("Inner"));
     QAction* co = menu.addAction(QObject::tr("Outer"));
+    QAction* cs = menu.addAction(QObject::tr("Split"));
     QAction* ca = menu.addAction(QObject::tr("Cancel"));
 
+    ci->setVisible(testRole(SelectionRole::Inner));
+    co->setVisible(testRole(SelectionRole::Outer));
+    cs->setVisible(testRole(SelectionRole::Split));
+
     if (getPositions().size() < 3) {
         ci->setEnabled(false);
         co->setEnabled(false);
@@ -455,17 +462,25 @@ int PolyClipSelection::popupMenu()
     QAction* id = menu.exec(QCursor::pos());
 
     if (id == ci) {
-        m_bInner = true;
+        m_selectedRole = SelectionRole::Inner;
         return Finish;
     }
     else if (id == co) {
-        m_bInner = false;
+        m_selectedRole = SelectionRole::Outer;
         return Finish;
     }
-    else if (id == ca)
+    else if (id == cs) {
+        m_selectedRole = SelectionRole::Split;
+        return Finish;
+    }
+    else if (id == ca) {
+        m_selectedRole = SelectionRole::None;
         return Cancel;
-    else
+    }
+    else {
+        m_selectedRole = SelectionRole::None;
         return Restart;
+    }
 }
 
 // -----------------------------------------------------------------------------------
diff --git a/src/Gui/MouseSelection.h b/src/Gui/MouseSelection.h
index 1fb3aa59a6..132326bbb0 100644
--- a/src/Gui/MouseSelection.h
+++ b/src/Gui/MouseSelection.h
@@ -24,11 +24,13 @@
 #ifndef MOUSESELECTION_H
 #define MOUSESELECTION_H
 
+#include <bitset>
 #include <vector>
 #include <Inventor/SbLinear.h>
 #include <Inventor/SbVec2f.h>
 #include <QCursor>
-#include "GLPainter.h"
+#include <Gui/GLPainter.h>
+#include <Gui/Namespace.h>
 
 // forwards
 class QMouseEvent;
@@ -68,8 +70,8 @@ public:
     const std::vector<SbVec2s>& getPositions() const {
         return _clPoly;
     }
-    SbBool isInner() const {
-        return m_bInner;
+    SelectionRole selectedRole() const {
+        return m_selectedRole;
     }
 
     void redraw();
@@ -82,23 +84,23 @@ public:
 protected:
     virtual int mouseButtonEvent(const SoMouseButtonEvent* const, const QPoint&) {
         return 0;
-    };
-    virtual int locationEvent(const SoLocation2Event*    const, const QPoint&) {
+    }
+    virtual int locationEvent(const SoLocation2Event* const, const QPoint&) {
         return 0;
-    };
-    virtual int keyboardEvent(const SoKeyboardEvent*     const)                   {
+    }
+    virtual int keyboardEvent(const SoKeyboardEvent* const){
         return 0;
-    };
+    }
 
     /// drawing stuff
-    virtual void draw() {};
+    virtual void draw() {}
 
 protected:
     Gui::View3DInventorViewer* _pcView3D;
     QCursor m_cPrevCursor;
     int  m_iXold, m_iYold;
     int  m_iXnew, m_iYnew;
-    SbBool m_bInner;
+    SelectionRole m_selectedRole;
     std::vector<SbVec2s> _clPoly;
 };
 
@@ -161,8 +163,18 @@ public:
     PolyClipSelection();
     virtual ~PolyClipSelection();
 
+    inline void setRole(SelectionRole pos, bool on) {
+        selectionBits.set(static_cast<size_t>(pos), on);
+    }
+    inline bool testRole(SelectionRole pos) const {
+        return selectionBits.test(static_cast<size_t>(pos));
+    }
+
 protected:
     virtual int popupMenu();
+
+private:
+    std::bitset<8> selectionBits;
 };
 
 // -----------------------------------------------------------------------------------
diff --git a/src/Gui/Namespace.h b/src/Gui/Namespace.h
new file mode 100644
index 0000000000..4ad28616cd
--- /dev/null
+++ b/src/Gui/Namespace.h
@@ -0,0 +1,42 @@
+/***************************************************************************
+ *   Copyright (c) 2018 Werner Mayer <wmayer[at]users.sourceforge.net>     *
+ *                                                                         *
+ *   This file is part of the FreeCAD CAx development system.              *
+ *                                                                         *
+ *   This library is free software; you can redistribute it and/or         *
+ *   modify it under the terms of the GNU Library General Public           *
+ *   License as published by the Free Software Foundation; either          *
+ *   version 2 of the License, or (at your option) any later version.      *
+ *                                                                         *
+ *   This library  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 Library General Public License for more details.                  *
+ *                                                                         *
+ *   You should have received a copy of the GNU Library General Public     *
+ *   License along with this library; see the file COPYING.LIB. If not,    *
+ *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
+ *   Suite 330, Boston, MA  02111-1307, USA                                *
+ *                                                                         *
+ ***************************************************************************/
+
+
+#ifndef GUI_NAMESPACE_H
+#define GUI_NAMESPACE_H
+
+
+namespace Gui {
+
+enum SelectionRole {
+    None = 0,
+    Inner = 1,
+    Outer = 2,
+    Split = 3,
+    Custom0 = 4,
+    Custom1 = 5,
+    Custom2 = 6,
+};
+
+} // namespace Gui
+
+#endif // GUI_NAMESPACE_H
diff --git a/src/Gui/NavigationStyle.cpp b/src/Gui/NavigationStyle.cpp
index fe92f8995f..489834fb3b 100644
--- a/src/Gui/NavigationStyle.cpp
+++ b/src/Gui/NavigationStyle.cpp
@@ -1315,10 +1315,10 @@ SbBool NavigationStyle::isSelecting() const
     return (mouseSelection ? true : false);
 }
 
-const std::vector<SbVec2s>& NavigationStyle::getPolygon(SbBool* clip_inner) const
+const std::vector<SbVec2s>& NavigationStyle::getPolygon(SelectionRole* role) const
 {
-    if (clip_inner)
-        *clip_inner = this->clipInner;
+    if (role)
+       *role = this->selectedRole;
     return pcPolygon;
 }
 
@@ -1429,7 +1429,7 @@ SbBool NavigationStyle::processEvent(const SoEvent * const ev)
         }
         else if (hd==AbstractMouseSelection::Finish) {
             pcPolygon = mouseSelection->getPositions();
-            clipInner = mouseSelection->isInner();
+            selectedRole = mouseSelection->selectedRole();
             delete mouseSelection; 
             mouseSelection = 0;
             syncWithEvent(ev);
diff --git a/src/Gui/NavigationStyle.h b/src/Gui/NavigationStyle.h
index 7f51dcae34..6144c73952 100644
--- a/src/Gui/NavigationStyle.h
+++ b/src/Gui/NavigationStyle.h
@@ -36,6 +36,7 @@
 #include <QCursor>
 #include <QEvent>
 #include <Base/BaseClass.h>
+#include <Gui/Namespace.h>
 
 // forward declarations
 class SoEvent;
@@ -157,7 +158,7 @@ public:
     void startSelection(SelectionMode = Lasso);
     void stopSelection();
     SbBool isSelecting() const;
-    const std::vector<SbVec2s>& getPolygon(SbBool* clip_inner=0) const;
+    const std::vector<SbVec2s>& getPolygon(SelectionRole* role=0) const;
 
     void setOrbitStyle(OrbitStyle style);
     OrbitStyle getOrbitStyle() const;
@@ -238,7 +239,7 @@ protected:
     //@{
     AbstractMouseSelection* mouseSelection;
     std::vector<SbVec2s> pcPolygon;
-    SbBool clipInner;
+    SelectionRole selectedRole;
     //@}
 
     /** @name Spinning data */
diff --git a/src/Gui/View3DInventorViewer.cpp b/src/Gui/View3DInventorViewer.cpp
index 9e4f3f02e9..7584292eac 100644
--- a/src/Gui/View3DInventorViewer.cpp
+++ b/src/Gui/View3DInventorViewer.cpp
@@ -1175,9 +1175,9 @@ bool View3DInventorViewer::isSelecting() const
     return navigation->isSelecting();
 }
 
-const std::vector<SbVec2s>& View3DInventorViewer::getPolygon(SbBool* clip_inner) const
+const std::vector<SbVec2s>& View3DInventorViewer::getPolygon(SelectionRole* role) const
 {
-    return navigation->getPolygon(clip_inner);
+    return navigation->getPolygon(role);
 }
 
 SbVec2f View3DInventorViewer::screenCoordsOfPath(SoPath* path) const
@@ -1263,9 +1263,9 @@ std::vector<SbVec2f> View3DInventorViewer::getGLPolygon(const std::vector<SbVec2
     return poly;
 }
 
-std::vector<SbVec2f> View3DInventorViewer::getGLPolygon(SbBool* clip_inner) const
+std::vector<SbVec2f> View3DInventorViewer::getGLPolygon(SelectionRole* role) const
 {
-    const std::vector<SbVec2s>& pnts = navigation->getPolygon(clip_inner);
+    const std::vector<SbVec2s>& pnts = navigation->getPolygon(role);
     return getGLPolygon(pnts);
 }
 
diff --git a/src/Gui/View3DInventorViewer.h b/src/Gui/View3DInventorViewer.h
index e9d517109c..bdef962a6b 100644
--- a/src/Gui/View3DInventorViewer.h
+++ b/src/Gui/View3DInventorViewer.h
@@ -38,6 +38,7 @@
 #include <QImage>
 
 #include <Gui/Selection.h>
+#include <Gui/Namespace.h>
 
 class SoTranslation;
 class SoTransform;
@@ -217,9 +218,9 @@ public:
     void startSelection(SelectionMode = Lasso);
     void stopSelection();
     bool isSelecting() const;
-    std::vector<SbVec2f> getGLPolygon(SbBool* clip_inner=0) const;
+    std::vector<SbVec2f> getGLPolygon(SelectionRole* role=0) const;
     std::vector<SbVec2f> getGLPolygon(const std::vector<SbVec2s>&) const;
-    const std::vector<SbVec2s>& getPolygon(SbBool* clip_inner=0) const;
+    const std::vector<SbVec2s>& getPolygon(SelectionRole* role=0) const;
     //@}
     
     /// Returns the screen coordinates of the origin of the path's tail object
diff --git a/src/Mod/Fem/Gui/Command.cpp b/src/Mod/Fem/Gui/Command.cpp
index 085ab42e1a..54ba1230de 100644
--- a/src/Mod/Fem/Gui/Command.cpp
+++ b/src/Mod/Fem/Gui/Command.cpp
@@ -916,8 +916,8 @@ void DefineNodesCallback(void * ud, SoEventCallback * n)
     view->removeEventCallback(SoMouseButtonEvent::getClassTypeId(), DefineNodesCallback,ud);
     n->setHandled();
 
-    SbBool clip_inner;
-    std::vector<SbVec2f> clPoly = view->getGLPolygon(&clip_inner);
+    Gui::SelectionRole role;
+    std::vector<SbVec2f> clPoly = view->getGLPolygon(&role);
     if (clPoly.size() < 3)
         return;
     if (clPoly.front() != clPoly.back())
diff --git a/src/Mod/Fem/Gui/TaskCreateNodeSet.cpp b/src/Mod/Fem/Gui/TaskCreateNodeSet.cpp
index 5b5515ab1f..9d14e38e3f 100644
--- a/src/Mod/Fem/Gui/TaskCreateNodeSet.cpp
+++ b/src/Mod/Fem/Gui/TaskCreateNodeSet.cpp
@@ -141,8 +141,8 @@ void TaskCreateNodeSet::DefineNodesCallback(void * ud, SoEventCallback * n)
     view->removeEventCallback(SoMouseButtonEvent::getClassTypeId(), DefineNodesCallback,ud);
     n->setHandled();
 
-    SbBool clip_inner;
-    std::vector<SbVec2f> clPoly = view->getGLPolygon(&clip_inner);
+    Gui::SelectionRole role;
+    std::vector<SbVec2f> clPoly = view->getGLPolygon(&role);
     if (clPoly.size() < 3)
         return;
     if (clPoly.front() != clPoly.back())
@@ -155,8 +155,7 @@ void TaskCreateNodeSet::DefineNodesCallback(void * ud, SoEventCallback * n)
     for (std::vector<SbVec2f>::const_iterator it = clPoly.begin(); it != clPoly.end(); ++it)
         polygon.Add(Base::Vector2d((*it)[0],(*it)[1]));
 
-    taskBox->DefineNodes(polygon,proj,clip_inner);
-
+    taskBox->DefineNodes(polygon,proj,role == Gui::SelectionRole::Inner ? true : false);
 }
 
 void TaskCreateNodeSet::DefineNodes(const Base::Polygon2d &polygon,const Gui::ViewVolumeProjection &proj,bool inner)
diff --git a/src/Mod/Mesh/Gui/Command.cpp b/src/Mod/Mesh/Gui/Command.cpp
index b3dce9fe98..80e13ab637 100644
--- a/src/Mod/Mesh/Gui/Command.cpp
+++ b/src/Mod/Mesh/Gui/Command.cpp
@@ -743,7 +743,8 @@ void CmdMeshPolySegm::activated(int)
                 Gui::View3DInventorViewer* viewer = ((Gui::View3DInventor*)view)->getViewer();
                 viewer->setEditing(true);
                 viewer->startSelection(Gui::View3DInventorViewer::Clip);
-                viewer->addEventCallback(SoMouseButtonEvent::getClassTypeId(), MeshGui::ViewProviderMeshFaceSet::segmMeshCallback);
+                viewer->addEventCallback(SoMouseButtonEvent::getClassTypeId(),
+                                         MeshGui::ViewProviderMeshFaceSet::segmMeshCallback);
             }
             else {
                 return;
@@ -898,10 +899,12 @@ void CmdMeshPolyCut::activated(int)
                 viewer->setEditing(true);
 
                 Gui::PolyClipSelection* clip = new Gui::PolyClipSelection();
+                clip->setRole(Gui::SelectionRole::Split, true);
                 clip->setColor(0.0f,0.0f,1.0f);
                 clip->setLineWidth(1.0f);
                 viewer->navigationStyle()->startSelection(clip);
-                viewer->addEventCallback(SoMouseButtonEvent::getClassTypeId(), MeshGui::ViewProviderMeshFaceSet::clipMeshCallback);
+                viewer->addEventCallback(SoMouseButtonEvent::getClassTypeId(),
+                                         MeshGui::ViewProviderMeshFaceSet::clipMeshCallback);
             }
             else {
                 return;
@@ -954,9 +957,14 @@ void CmdMeshPolyTrim::activated(int)
             if (view->getTypeId().isDerivedFrom(Gui::View3DInventor::getClassTypeId())) {
                 Gui::View3DInventorViewer* viewer = ((Gui::View3DInventor*)view)->getViewer();
                 viewer->setEditing(true);
-                viewer->startSelection(Gui::View3DInventorViewer::Clip);
+
+                Gui::PolyClipSelection* clip = new Gui::PolyClipSelection();
+                clip->setRole(Gui::SelectionRole::Split, true);
+                clip->setColor(0.0f,0.0f,1.0f);
+                clip->setLineWidth(1.0f);
+                viewer->navigationStyle()->startSelection(clip);
                 viewer->addEventCallback(SoMouseButtonEvent::getClassTypeId(),
-                    MeshGui::ViewProviderMeshFaceSet::trimMeshCallback);
+                                         MeshGui::ViewProviderMeshFaceSet::trimMeshCallback);
             }
             else {
                 return;
@@ -1066,7 +1074,8 @@ void CmdMeshPolySplit::activated(int)
                 Gui::View3DInventorViewer* viewer = ((Gui::View3DInventor*)view)->getViewer();
                 viewer->setEditing(true);
                 viewer->startSelection(Gui::View3DInventorViewer::Clip);
-                viewer->addEventCallback(SoMouseButtonEvent::getClassTypeId(), MeshGui::ViewProviderMeshFaceSet::partMeshCallback);
+                viewer->addEventCallback(SoMouseButtonEvent::getClassTypeId(),
+                                         MeshGui::ViewProviderMeshFaceSet::partMeshCallback);
             }
             else {
                 return;
diff --git a/src/Mod/Mesh/Gui/ViewProvider.cpp b/src/Mod/Mesh/Gui/ViewProvider.cpp
index 260318173e..1b0255ac06 100644
--- a/src/Mod/Mesh/Gui/ViewProvider.cpp
+++ b/src/Mod/Mesh/Gui/ViewProvider.cpp
@@ -27,6 +27,7 @@
 # include <stdlib.h>
 # include <QAction>
 # include <QMenu>
+# include <QTimer>
 # include <Inventor/SbBox2s.h>
 # include <Inventor/SbLine.h>
 # include <Inventor/SbPlane.h>
@@ -813,6 +814,58 @@ void ViewProviderMesh::showOpenEdges(bool show)
     (void)show;
 }
 
+namespace MeshGui {
+class MeshSplit {
+public:
+    MeshSplit(ViewProviderMesh* mesh,
+              const std::vector<SbVec2f>& poly,
+              const Gui::ViewVolumeProjection& proj)
+        : mesh(mesh)
+        , poly(poly)
+        , proj(proj)
+    {
+
+    }
+    ~MeshSplit() {
+
+    }
+    void cutMesh() {
+        Gui::Document* gui = mesh->getDocument();
+        gui->openCommand("Cut");
+        ViewProviderMesh* copy = makeCopy();
+        mesh->cutMesh(poly, proj, false);
+        copy->cutMesh(poly, proj, true);
+        gui->commitCommand();
+        delete this;
+    }
+    void trimMesh() {
+        Gui::Document* gui = mesh->getDocument();
+        gui->openCommand("Trim");
+        ViewProviderMesh* copy = makeCopy();
+        mesh->trimMesh(poly, proj, false);
+        copy->trimMesh(poly, proj, true);
+        gui->commitCommand();
+        delete this;
+    }
+    ViewProviderMesh* makeCopy() const {
+        Gui::Document* gui = mesh->getDocument();
+        App::Document* doc = gui->getDocument();
+
+        Mesh::Feature* cpy = static_cast<Mesh::Feature*>(doc->addObject("Mesh::Feature"));
+        Mesh::Feature* org = static_cast<Mesh::Feature*>(mesh->getObject());
+        cpy->Label.setValue(org->Label.getValue());
+        cpy->Mesh.setValue(org->Mesh.getValue());
+
+        return static_cast<ViewProviderMesh*>(gui->getViewProvider(cpy));
+    }
+
+private:
+    ViewProviderMesh* mesh;
+    Gui::ViewVolumeProjection proj;
+    std::vector<SbVec2f> poly;
+};
+}
+
 void ViewProviderMesh::clipMeshCallback(void * ud, SoEventCallback * n)
 {
     // show the wait cursor because this could take quite some time
@@ -824,8 +877,8 @@ void ViewProviderMesh::clipMeshCallback(void * ud, SoEventCallback * n)
     view->removeEventCallback(SoMouseButtonEvent::getClassTypeId(), clipMeshCallback,ud);
     n->setHandled();
 
-    SbBool clip_inner;
-    std::vector<SbVec2f> clPoly = view->getGLPolygon(&clip_inner);
+    Gui::SelectionRole role;
+    std::vector<SbVec2f> clPoly = view->getGLPolygon(&role);
     if (clPoly.size() < 3)
         return;
     if (clPoly.front() != clPoly.back())
@@ -834,6 +887,7 @@ void ViewProviderMesh::clipMeshCallback(void * ud, SoEventCallback * n)
     std::vector<Gui::ViewProvider*> views = view->getViewProvidersOfType(ViewProviderMesh::getClassTypeId());
     if (!views.empty()) {
         Gui::Application::Instance->activeDocument()->openCommand("Cut");
+        bool commitCommand = false;
         for (std::vector<Gui::ViewProvider*>::iterator it = views.begin(); it != views.end(); ++it) {
             ViewProviderMesh* self = static_cast<ViewProviderMesh*>(*it);
             if (self->getEditingMode() > -1) {
@@ -843,11 +897,31 @@ void ViewProviderMesh::clipMeshCallback(void * ud, SoEventCallback * n)
                 Gui::ViewVolumeProjection proj(vv);
                 proj.setTransform(static_cast<Mesh::Feature*>(self->getObject())->
                                   Placement.getValue().toMatrix());
-                self->cutMesh(clPoly, proj, clip_inner);
+                if (role == Gui::SelectionRole::Inner) {
+                    self->cutMesh(clPoly, proj, true);
+                    commitCommand = true;
+                }
+                else if (role == Gui::SelectionRole::Outer) {
+                    self->cutMesh(clPoly, proj, false);
+                    commitCommand = true;
+                }
+                else if (role == Gui::SelectionRole::Split) {
+                    // We must delay the split because it adds a new
+                    // node to the scenegraph which cannot be done while
+                    // traversing it
+                    Gui::TimerFunction* func = new Gui::TimerFunction();
+                    func->setAutoDelete(true);
+                    MeshSplit* split = new MeshSplit(self, clPoly, proj);
+                    func->setFunction(boost::bind(&MeshSplit::cutMesh, split));
+                    QTimer::singleShot(0, func, SLOT(timeout()));
+                }
             }
         }
 
-        Gui::Application::Instance->activeDocument()->commitCommand();
+        if (commitCommand)
+            Gui::Application::Instance->activeDocument()->commitCommand();
+        else
+            Gui::Application::Instance->activeDocument()->abortCommand();
 
         view->redraw();
     }
@@ -864,8 +938,8 @@ void ViewProviderMesh::trimMeshCallback(void * ud, SoEventCallback * n)
     view->removeEventCallback(SoMouseButtonEvent::getClassTypeId(), trimMeshCallback,ud);
     n->setHandled();
 
-    SbBool clip_inner;
-    std::vector<SbVec2f> clPoly = view->getGLPolygon(&clip_inner);
+    Gui::SelectionRole role;
+    std::vector<SbVec2f> clPoly = view->getGLPolygon(&role);
     if (clPoly.size() < 3)
         return;
     if (clPoly.front() != clPoly.back())
@@ -873,7 +947,8 @@ void ViewProviderMesh::trimMeshCallback(void * ud, SoEventCallback * n)
 
     std::vector<Gui::ViewProvider*> views = view->getViewProvidersOfType(ViewProviderMesh::getClassTypeId());
     if (!views.empty()) {
-        Gui::Application::Instance->activeDocument()->openCommand("Cut");
+        Gui::Application::Instance->activeDocument()->openCommand("Trim");
+        bool commitCommand = false;
         for (std::vector<Gui::ViewProvider*>::iterator it = views.begin(); it != views.end(); ++it) {
             ViewProviderMesh* self = static_cast<ViewProviderMesh*>(*it);
             if (self->getEditingMode() > -1) {
@@ -883,11 +958,31 @@ void ViewProviderMesh::trimMeshCallback(void * ud, SoEventCallback * n)
                 Gui::ViewVolumeProjection proj(vv);
                 proj.setTransform(static_cast<Mesh::Feature*>(self->getObject())->
                                   Placement.getValue().toMatrix());
-                self->trimMesh(clPoly, proj, clip_inner);
+                if (role == Gui::SelectionRole::Inner) {
+                    self->trimMesh(clPoly, proj, true);
+                    commitCommand = true;
+                }
+                else if (role == Gui::SelectionRole::Outer) {
+                    self->trimMesh(clPoly, proj, false);
+                    commitCommand = true;
+                }
+                else if (role == Gui::SelectionRole::Split) {
+                    // We must delay the split because it adds a new
+                    // node to the scenegraph which cannot be done while
+                    // traversing it
+                    Gui::TimerFunction* func = new Gui::TimerFunction();
+                    func->setAutoDelete(true);
+                    MeshSplit* split = new MeshSplit(self, clPoly, proj);
+                    func->setFunction(boost::bind(&MeshSplit::trimMesh, split));
+                    QTimer::singleShot(0, func, SLOT(timeout()));
+                }
             }
         }
 
-        Gui::Application::Instance->activeDocument()->commitCommand();
+        if (commitCommand)
+            Gui::Application::Instance->activeDocument()->commitCommand();
+        else
+            Gui::Application::Instance->activeDocument()->abortCommand();
 
         view->redraw();
     }
@@ -904,8 +999,8 @@ void ViewProviderMesh::partMeshCallback(void * ud, SoEventCallback * cb)
     view->removeEventCallback(SoMouseButtonEvent::getClassTypeId(), partMeshCallback,ud);
     cb->setHandled();
 
-    SbBool clip_inner;
-    std::vector<SbVec2f> clPoly = view->getGLPolygon(&clip_inner);
+    Gui::SelectionRole role;
+    std::vector<SbVec2f> clPoly = view->getGLPolygon(&role);
     if (clPoly.size() < 3)
         return;
     if (clPoly.front() != clPoly.back())
@@ -941,7 +1036,10 @@ void ViewProviderMesh::partMeshCallback(void * ud, SoEventCallback * cb)
                 plm.invert();
                 MeshCore::MeshKernel copyToolMesh(toolMesh);
                 copyToolMesh.Transform(plm.toMatrix());
-                that->splitMesh(copyToolMesh, cNormal, clip_inner);
+                if (role == Gui::SelectionRole::Inner)
+                    that->splitMesh(copyToolMesh, cNormal, true);
+                else
+                    that->splitMesh(copyToolMesh, cNormal, false);
             }
         }
     }
@@ -965,8 +1063,8 @@ void ViewProviderMesh::segmMeshCallback(void * ud, SoEventCallback * cb)
     view->removeEventCallback(SoMouseButtonEvent::getClassTypeId(), segmMeshCallback,ud);
     cb->setHandled();
 
-    SbBool clip_inner;
-    std::vector<SbVec2f> clPoly = view->getGLPolygon(&clip_inner);
+    Gui::SelectionRole role;
+    std::vector<SbVec2f> clPoly = view->getGLPolygon(&role);
     if (clPoly.size() < 3)
         return;
     if (clPoly.front() != clPoly.back())
@@ -1002,7 +1100,10 @@ void ViewProviderMesh::segmMeshCallback(void * ud, SoEventCallback * cb)
                 plm.invert();
                 MeshCore::MeshKernel copyToolMesh(toolMesh);
                 copyToolMesh.Transform(plm.toMatrix());
-                that->segmentMesh(copyToolMesh, cNormal, clip_inner);
+                if (role == Gui::SelectionRole::Inner)
+                    that->segmentMesh(copyToolMesh, cNormal, true);
+                else
+                    that->segmentMesh(copyToolMesh, cNormal, false);
             }
         }
     }
diff --git a/src/Mod/Mesh/Gui/ViewProvider.h b/src/Mod/Mesh/Gui/ViewProvider.h
index 8adc3b0354..e5636eb449 100644
--- a/src/Mod/Mesh/Gui/ViewProvider.h
+++ b/src/Mod/Mesh/Gui/ViewProvider.h
@@ -158,6 +158,8 @@ public:
     std::vector<unsigned long> getFacetsOfRegion(const SbViewportRegion&, const SbViewportRegion&, SoCamera*) const;
     std::vector<unsigned long> getVisibleFacetsAfterZoom(const SbBox2s&, const SbViewportRegion&, SoCamera*) const;
     std::vector<unsigned long> getVisibleFacets(const SbViewportRegion&, SoCamera*) const;
+    virtual void cutMesh(const std::vector<SbVec2f>& picked, const Base::ViewProjMethod& proj, SbBool inner);
+    virtual void trimMesh(const std::vector<SbVec2f>& picked, const Base::ViewProjMethod& proj, SbBool inner);
     virtual void removeFacets(const std::vector<unsigned long>&);
     /*! The size of the array must be equal to the number of facets. */
     void setFacetTransparency(const std::vector<float>&);
@@ -174,8 +176,6 @@ protected:
     void onChanged(const App::Property* prop);
     virtual void showOpenEdges(bool);
     void setOpenEdgeColorFrom(const App::Color& col);
-    virtual void cutMesh(const std::vector<SbVec2f>& picked, const Base::ViewProjMethod& proj, SbBool inner);
-    virtual void trimMesh(const std::vector<SbVec2f>& picked, const Base::ViewProjMethod& proj, SbBool inner);
     virtual void splitMesh(const MeshCore::MeshKernel& toolMesh, const Base::Vector3f& normal, SbBool inner);
     virtual void segmentMesh(const MeshCore::MeshKernel& toolMesh, const Base::Vector3f& normal, SbBool inner);
     virtual void faceInfo(unsigned long facet);
diff --git a/src/Mod/Mesh/Gui/Workbench.cpp b/src/Mod/Mesh/Gui/Workbench.cpp
index 84940f6fe8..95f3458f8b 100644
--- a/src/Mod/Mesh/Gui/Workbench.cpp
+++ b/src/Mod/Mesh/Gui/Workbench.cpp
@@ -192,9 +192,8 @@ Gui::MenuItem* Workbench::setupMenuBar() const
     Gui::MenuItem* cutting = new Gui::MenuItem;
     cutting->setCommand("Cutting");
     *cutting << "Mesh_PolyCut"
-             << "Mesh_PolySplit"
-             << "Mesh_PolySegm"
              << "Mesh_PolyTrim"
+           //<< "Mesh_PolySegm"
              << "Mesh_TrimByPlane"
              << "Mesh_SectionByPlane";
 
diff --git a/src/Mod/MeshPart/Gui/Command.cpp b/src/Mod/MeshPart/Gui/Command.cpp
index f4bc43201d..1a768cd556 100644
--- a/src/Mod/MeshPart/Gui/Command.cpp
+++ b/src/Mod/MeshPart/Gui/Command.cpp
@@ -102,26 +102,20 @@ void CmdMeshPartTrimByPlane::activated(int)
     msgBox.setText(qApp->translate("MeshPart_TrimByPlane","Select the side you want to keep."));
     QPushButton* inner = msgBox.addButton(qApp->translate("MeshPart_TrimByPlane","Inner"), QMessageBox::ActionRole);
     QPushButton* outer = msgBox.addButton(qApp->translate("MeshPart_TrimByPlane","Outer"), QMessageBox::ActionRole);
-    QPushButton* both = msgBox.addButton(qApp->translate("MeshPart_TrimByPlane","Both"), QMessageBox::ActionRole);
+    QPushButton* split = msgBox.addButton(qApp->translate("MeshPart_TrimByPlane","Split"), QMessageBox::ActionRole);
     msgBox.setDefaultButton(inner);
     msgBox.exec();
     QAbstractButton* click = msgBox.clickedButton();
 
-    enum Side {
-        Inner,
-        Outer,
-        Both
-    };
-
-    Side side;
+    Gui::SelectionRole role;
     if (inner == click) {
-        side = Inner;
+        role = Gui::SelectionRole::Inner;
     }
     else if (outer == click) {
-        side = Outer;
+        role = Gui::SelectionRole::Outer;
     }
-    else if (both == click) {
-        side = Both;
+    else if (split == click) {
+        role = Gui::SelectionRole::Split;
     }
     else {
         // abort
@@ -168,15 +162,15 @@ void CmdMeshPartTrimByPlane::activated(int)
         polygon2d.Add(Base::Vector2d(p3.x, p3.y));
         polygon2d.Add(Base::Vector2d(p4.x, p4.y));
 
-        if (side == Inner) {
+        if (role == Gui::SelectionRole::Inner) {
             mesh->trim(polygon2d, proj, Mesh::MeshObject::INNER);
             static_cast<Mesh::Feature*>(*it)->Mesh.finishEditing();
         }
-        else if (side == Outer) {
+        else if (role == Gui::SelectionRole::Outer) {
             mesh->trim(polygon2d, proj, Mesh::MeshObject::OUTER);
             static_cast<Mesh::Feature*>(*it)->Mesh.finishEditing();
         }
-        else if (side == Both) {
+        else if (role == Gui::SelectionRole::Split) {
             Mesh::MeshObject copy(*mesh);
             mesh->trim(polygon2d, proj, Mesh::MeshObject::INNER);
             static_cast<Mesh::Feature*>(*it)->Mesh.finishEditing();