When moving an angle, we did not take into account the case where they are reversed. This fixes that.

src/Mod/Sketcher/App/SketchObject.cpp

@@ -664,7 +664,12 @@ void SketchObject::reverseAngleConstraintToSupplementary(Constraint* constr, int
 {
     std::swap(constr->First, constr->Second);
     std::swap(constr->FirstPos, constr->SecondPos);
-    constr->FirstPos = (constr->FirstPos == Sketcher::PointPos::start) ? Sketcher::PointPos::end : Sketcher::PointPos::start;
+    if (constr->FirstPos == constr->SecondPos) {
+        constr->FirstPos = (constr->FirstPos == Sketcher::PointPos::start) ? Sketcher::PointPos::end : Sketcher::PointPos::start;
+    }
+    else {
+        constr->SecondPos = (constr->SecondPos == Sketcher::PointPos::start) ? Sketcher::PointPos::end : Sketcher::PointPos::start;
+    }
 
     // Edit the expression if any, else modify constraint value directly
     if (constraintHasExpression(constNum)) {
@@ -677,6 +682,12 @@ void SketchObject::reverseAngleConstraintToSupplementary(Constraint* constr, int
     }
 }
 
+void SketchObject::inverseAngleConstraint(Constraint* constr)
+{
+    constr->FirstPos = (constr->FirstPos == Sketcher::PointPos::start) ? Sketcher::PointPos::end : Sketcher::PointPos::start;
+    constr->SecondPos = (constr->SecondPos == Sketcher::PointPos::start) ? Sketcher::PointPos::end : Sketcher::PointPos::start;
+}
+
 bool SketchObject::constraintHasExpression(int constNum) const
 {
     App::ObjectIdentifier path = Constraints.createPath(constNum);

src/Mod/Sketcher/App/SketchObject.h

@@ -271,6 +271,7 @@ public:
 
     /// Change an angle constraint to its supplementary angle.
     void reverseAngleConstraintToSupplementary(Constraint* constr, int constNum);
+    void inverseAngleConstraint(Constraint* constr);
     /// Modify an angle constraint expression string to its supplementary angle
     static std::string reverseAngleConstraintExpression(std::string expression);
 

src/Mod/Sketcher/Gui/ViewProviderSketch.cpp

@@ -1918,8 +1918,12 @@ void ViewProviderSketch::moveAngleConstraint(int constNum, const Base::Vector2d&
                 sign2 = isLeftOfLine(p21, p22, ap3);
             }
 
+            bool inverse = !(sign1 == sign3 && sign2 == sign4);
+            if (inverse) {
+                obj->inverseAngleConstraint(constr);
+            }
+
             p0 = Base::Vector3d(intersection.x, intersection.y, 0.);
-            factor *= (sign1 == sign3 && sign2 == sign4) ? 1. : -1.;
         }
         else {// angle-via-point
             Base::Vector3d p = getSolvedSketch().getPoint(constr->Third, constr->ThirdPos);