Another try a allowing touching courtyards.

Fixes https://gitlab.com/kicad/code/kicad/issues/8076

libs/kimath/include/geometry/shape_poly_set.h

@@ -964,7 +964,7 @@ public:
      * @param aAmount is the number of units to offset edges.
      * @param aCircleSegmentsCount is the number of segments per 360 degrees to use in curve approx
      * @param aCornerStrategy #ALLOW_ACUTE_CORNERS to preserve all angles,
-     *                        #CHOP_ACUTE_CORNERS to chop angles less than 90°,
+     *                        #CHAMFER_ACUTE_CORNERS to chop angles less than 90°,
      *                        #ROUND_ACUTE_CORNERS to round off angles less than 90°,
      *                        #ROUND_ALL_CORNERS to round regardless of angles
      */

pcbnew/drc/drc_test_provider_courtyard_clearance.cpp

@@ -189,9 +189,6 @@ bool DRC_TEST_PROVIDER_COURTYARD_CLEARANCE::testCourtyardClearances()
                                                      test, F_Cu );
                 clearance = constraint.GetValue().Min();
 
-                // Touching courtyards, or courtyards -at- the clearance distance are legal.
-                clearance -= 1;
-
                 if( clearance >= 0 && footprintFront.Collide( &testFront, clearance, &actual, &pos ) )
                 {
                     std::shared_ptr<DRC_ITEM> drce = DRC_ITEM::Create( DRCE_OVERLAPPING_FOOTPRINTS );
@@ -219,9 +216,6 @@ bool DRC_TEST_PROVIDER_COURTYARD_CLEARANCE::testCourtyardClearances()
                                                      test, B_Cu );
                 clearance = constraint.GetValue().Min();
 
-                // Touching courtyards, or courtyards -at- the clearance distance are legal.
-                clearance -= 1;
-
                 if( clearance >= 0 && footprintBack.Collide( &testBack, clearance, &actual, &pos ) )
                 {
                     std::shared_ptr<DRC_ITEM> drce = DRC_ITEM::Create( DRCE_OVERLAPPING_FOOTPRINTS );

pcbnew/footprint.cpp

@@ -1956,6 +1956,9 @@ void FOOTPRINT::BuildPolyCourtyards( OUTLINE_ERROR_HANDLER* aErrorHandler )
     if( ConvertOutlineToPolygon( list_front, m_poly_courtyard_front, errorMax, chainingEpsilon,
                                  aErrorHandler ) )
     {
+        // Touching courtyards, or courtyards -at- the clearance distance are legal.
+        m_poly_courtyard_front.Inflate( -1, SHAPE_POLY_SET::CHAMFER_ACUTE_CORNERS );
+
         m_poly_courtyard_front.CacheTriangulation( false );
     }
     else
@@ -1966,6 +1969,9 @@ void FOOTPRINT::BuildPolyCourtyards( OUTLINE_ERROR_HANDLER* aErrorHandler )
     if( ConvertOutlineToPolygon( list_back, m_poly_courtyard_back, errorMax, chainingEpsilon,
                                  aErrorHandler ) )
     {
+        // Touching courtyards, or courtyards -at- the clearance distance are legal.
+        m_poly_courtyard_back.Inflate( -1, SHAPE_POLY_SET::CHAMFER_ACUTE_CORNERS );
+
         m_poly_courtyard_back.CacheTriangulation( false );
     }
     else