Eeschema, print and plot: fix arc issue for lib arcs == 180 deg

Fixes #12502
https://gitlab.com/kicad/code/kicad/issues/12502

eeschema/lib_shape.cpp

@@ -167,7 +167,8 @@ void LIB_SHAPE::Plot( PLOTTER* aPlotter, bool aBackground, const VECTOR2I& aOffs
         // N.B. The order of evaluation is critical here as MapAngles will modify t1, t2
         // and the Normalize routine depends on these modifications for the correct output
         bool transformed = aTransform.MapAngles( &t1, &t2 );
-        bool transformed2 = ( ( t1 - t2 ).Normalize180() > ANGLE_0 );
+        EDA_ANGLE arc_angle =  ( t1 - t2 ).Normalize180();
+        bool transformed2 = ( arc_angle > ANGLE_0 ) && ( arc_angle < ANGLE_180 );
 
         if( transformed  != transformed2 )
             std::swap( start, end );
@@ -329,7 +330,8 @@ void LIB_SHAPE::print( const RENDER_SETTINGS* aSettings, const VECTOR2I& aOffset
         // N.B. The order of evaluation is critical here as MapAngles will modify t1, t2
         // and the Normalize routine depends on these modifications for the correct output
         bool transformed = aTransform.MapAngles( &t1, &t2 );
-        bool transformed2 = ( ( t1 - t2 ).Normalize180() > ANGLE_0 );
+        EDA_ANGLE arc_angle =  ( t1 - t2 ).Normalize180();
+        bool transformed2 = ( arc_angle > ANGLE_0 ) && ( arc_angle < ANGLE_180 );
 
         if( transformed  == transformed2 )
             std::swap( pt1, pt2 );