fixes 0003410: 0.17 Regression: recompute will make parts lose color and take a longer delay compared to FC0.16

src/Mod/Sketcher/App/SketchObject.cpp

@@ -142,6 +142,17 @@ SketchObject::~SketchObject()
     delete analyser;
 }
 
+short SketchObject::mustExecute() const
+{
+    if (Geometry.isTouched())
+        return 1;
+    if (Constraints.isTouched())
+        return 1;
+    if (ExternalGeometry.isTouched())
+        return 1;
+    return Part2DObject::mustExecute();
+}
+
 App::DocumentObjectExecReturn *SketchObject::execute(void)
 {
     try {

src/Mod/Sketcher/App/SketchObject.h

@@ -66,6 +66,7 @@ public:
     App     ::PropertyLinkSubList    ExternalGeometry;
     /** @name methods override Feature */
     //@{
+    short mustExecute() const;
     /// recalculate the Feature (if no recompute is needed see also solve() and solverNeedsUpdate boolean)
     App::DocumentObjectExecReturn *execute(void);