diff --git a/eeschema/load_one_schematic_file.cpp b/eeschema/load_one_schematic_file.cpp
index 1bca27f4a7..b1aeb0ab5d 100644
--- a/eeschema/load_one_schematic_file.cpp
+++ b/eeschema/load_one_schematic_file.cpp
@@ -304,8 +304,8 @@ bool ReadSchemaDescr( LINE_READER* aLine, wxString& aMsgDiag, SCH_SCREEN* aScree
 
     if( !pageInfo.SetType( pagename ) )
     {
-        aMsgDiag.Printf( _( "Eeschema file dimension definition error \
-line %d,\nAbort reading file.\n" ),
+        aMsgDiag.Printf( _( "Eeschema file dimension definition error line %d,"
+                            "\nAbort reading file.\n" ),
                          aLine->LineNumber() );
         aMsgDiag << FROM_UTF8( line );
     }
diff --git a/pcbnew/zone_filling_algorithm.cpp b/pcbnew/zone_filling_algorithm.cpp
index 589c031e5e..3779e7b433 100644
--- a/pcbnew/zone_filling_algorithm.cpp
+++ b/pcbnew/zone_filling_algorithm.cpp
@@ -82,8 +82,12 @@ bool ZONE_CONTAINER::BuildFilledSolidAreasPolygons( BOARD* aPcb, CPOLYGONS_LIST*
         break;
 
     default:
-        m_smoothedPoly = new CPolyLine;
-        m_smoothedPoly->Copy( m_Poly );
+        // Acute angles between adjacent edges can create issues in calculations,
+        // in inflate/deflate outlines transforms, especially when the angle is very small.
+        // We can avoid issues by creating a very small chamfer which remove acute angles,
+        // or left it without chamfer and use only CPOLYGONS_LIST::InflateOutline to create
+        // clearance areas
+        m_smoothedPoly = m_Poly->Chamfer( Millimeter2iu( 0.0 ) );
         break;
     }
 
diff --git a/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp b/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
index 0316d473a3..d527206a96 100644
--- a/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
+++ b/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
@@ -154,7 +154,7 @@ void ZONE_CONTAINER::AddClearanceAreasPolygonsToPolysList( BOARD* aPcb )
      * so m_ZoneMinThickness is the min thickness of the filled zones areas
      * the main polygon is stored in polyset_zone_solid_areas
      */
-#if 1
+#if 0
     m_smoothedPoly->m_CornersList.ExportTo( polyset_zone_solid_areas );
 
     if( polyset_zone_solid_areas.size() == 0 )
@@ -181,6 +181,9 @@ void ZONE_CONTAINER::AddClearanceAreasPolygonsToPolysList( BOARD* aPcb )
     CPOLYGONS_LIST tmp;
     m_smoothedPoly->m_CornersList.InflateOutline( tmp, -outline_half_thickness, true );
     tmp.ExportTo( polyset_zone_solid_areas );
+
+    if( polyset_zone_solid_areas.size() == 0 )
+        return;
 #endif
 
     /* Calculates the clearance value that meet DRC requirements
diff --git a/polygon/PolyLine.cpp b/polygon/PolyLine.cpp
index 47d29e3843..8e8714bcdd 100644
--- a/polygon/PolyLine.cpp
+++ b/polygon/PolyLine.cpp
@@ -1440,7 +1440,23 @@ void CPOLYGONS_LIST::ImportFrom( ClipperLib::Paths& aPolygons )
  * aInflateValue = the Inflate value. when < 0, this is a deflate transform
  * aLinkHoles = if true, aResult contains only one polygon,
  * with holes linked by overlapping segments
+ *
+ * Important Note:
+ * Inflating a polygon with acute angles or a non convex polygon gives non optimal shapes
+ * for your purposes (creating a clearance area from zones).
+ * So when inflating a polygon, we combine it with a "thick outline"
+ * with a thickness = aInflateValue*2.
+ * the inflated polygon shape is much better to build a polygon
+ * from a polygon + clearance area
+ *
+ * Generic algos (Clipper, Boost Polygon) can inflate polygons, but the result is
+ * not always suitable (they work fine only for polygons with non acute angle)
+ *
+ * To deflate polygons, the same calculation is made, but instead of adding the "thick outline"
+ * we substract it.
  */
+#include <convert_basic_shapes_to_polygon.h>
+
 void CPOLYGONS_LIST::InflateOutline( CPOLYGONS_LIST& aResult, int aInflateValue, bool aLinkHoles )
 {
     KI_POLYGON_SET polyset_outline;
@@ -1456,12 +1472,68 @@ void CPOLYGONS_LIST::InflateOutline( CPOLYGONS_LIST& aResult, int aInflateValue,
     }
 
     // inflate main outline
+    unsigned icnt = 0;
+    int width = std::abs( aInflateValue * 2 );
+
     if( polyset_outline.size() )
-        polyset_outline += aInflateValue;
+    {
+        CPOLYGONS_LIST outlines;
+
+        for( ; icnt < GetCornersCount(); icnt++ )
+        {
+            unsigned ii = icnt+1;
+
+            if( IsEndContour( icnt ) )
+                ii = 0;
+
+            TransformRoundedEndsSegmentToPolygon( outlines,
+                            GetPos( icnt ), GetPos( ii ), 16, width );
+
+            if( IsEndContour( icnt ) )
+                break;
+        }
+
+        KI_POLYGON_SET thicklines;
+        outlines.ExportTo( thicklines );
+
+        if( aInflateValue > 0 )     // Inflate main outline
+            polyset_outline += thicklines;
+        else if( aInflateValue < 0 )    // Actually a deflate transform
+            polyset_outline -= thicklines;   // deflate main outline
+
+    }
 
     // deflate outline holes
     if( outlineHoles.size() )
-        outlineHoles -= aInflateValue;
+    {
+        int deflateValue = -aInflateValue;
+
+        CPOLYGONS_LIST outlines;
+        icnt += 1;   // points the first point of the first hole
+        unsigned firstpoint = icnt;
+
+        for( ; icnt < GetCornersCount(); icnt++ )
+        {
+            unsigned ii = icnt+1;
+
+            if( IsEndContour( icnt ) || ii >= GetCornersCount() )
+            {
+                ii = firstpoint;
+                firstpoint = icnt+1;
+            }
+
+            TransformRoundedEndsSegmentToPolygon( outlines,
+                            GetPos( icnt ), GetPos( ii ), 16, width );
+        }
+
+        KI_POLYGON_SET thicklines;
+        outlines.ExportTo( thicklines );
+
+        if( deflateValue > 0 )     // Inflate holes
+            outlineHoles += thicklines;
+        else if( deflateValue < 0 )    // deflate holes
+            outlineHoles -= thicklines;
+    }
 
     // Copy modified polygons
     if( !aLinkHoles )
@@ -1478,6 +1550,7 @@ void CPOLYGONS_LIST::InflateOutline( CPOLYGONS_LIST& aResult, int aInflateValue,
     }
 }
 
+
 /**
  * Function ConvertPolysListWithHolesToOnePolygon
  * converts the outline contours aPolysListWithHoles with holes to one polygon