Fix for incomplete commit causing thin gaps to throw an error

lib/Slic3r/ExtrusionLoop.pm

@@ -22,6 +22,11 @@ sub deserialize {
     $self->polygon($self->polygon->deserialize);
 }
 
+sub shortest_path {
+    my $self = shift;
+    return $self;
+}
+
 sub split_at {
     my $self = shift;
     my ($point) = @_;

lib/Slic3r/ExtrusionPath.pm

@@ -47,6 +47,11 @@ sub deserialize {
     $self->polyline($self->polyline->deserialize);
 }
 
+sub shortest_path {
+    my $self = shift;
+    return $self;
+}
+
 sub clip_end {
     my $self = shift;
     my ($distance) = @_;

lib/Slic3r/Print.pm

@@ -605,7 +605,7 @@ sub write_gcode {
             $gcode .= $gcodegen->set_tool($Slic3r::infill_extruder-1);
             $gcode .= $gcodegen->set_acceleration($Slic3r::infill_acceleration);
             for my $fill (@{ $layer->fills }) {
-                $gcode .= $gcodegen->extrude_path($_, 'fill') 
+                $gcode .= $gcodegen->extrude($_, 'fill') 
                     for $fill->shortest_path($gcodegen->last_pos);
             }