From 19548fe301040b61e41ccbfa4a9bf7298038f096 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Wed, 24 Dec 2014 12:02:42 +0100
Subject: [PATCH] Don't perform wiping if we have just changed layer and no
 extrusions were performed before the first retraction. Includes regression
 test. #2214

---
 lib/Slic3r/GCode.pm |  4 ++++
 t/gcode.t           | 15 +++++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index 2e189c4996..6f6ba2dab1 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -96,6 +96,10 @@ sub change_layer {
         $gcode .= $self->retract;
     }
     $gcode .= $self->writer->travel_to_z($z, 'move to next layer (' . $self->layer->id . ')');
+    
+    # forget last wiping path as wiping after raising Z is pointless
+    $self->wipe->path(undef);
+    
     return $gcode;
 }
 
diff --git a/t/gcode.t b/t/gcode.t
index 17393e7cf0..aa15098a0e 100644
--- a/t/gcode.t
+++ b/t/gcode.t
@@ -1,4 +1,4 @@
-use Test::More tests => 19;
+use Test::More tests => 20;
 use strict;
 use warnings;
 
@@ -24,14 +24,24 @@ use Slic3r::Test;
 {
     my $config = Slic3r::Config->new_from_defaults;
     $config->set('wipe', [1]);
+    $config->set('retract_layer_change', [0]);
     
     my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
     my $have_wipe = 0;
     my @retract_speeds = ();
+    my $extruded_on_this_layer = 0;
+    my $wiping_on_new_layer = 0;
     Slic3r::GCode::Reader->new->parse(Slic3r::Test::gcode($print), sub {
         my ($self, $cmd, $args, $info) = @_;
-        if ($info->{retracting} && $info->{dist_XY} > 0) {
+        
+        if ($info->{travel} && $info->{dist_Z}) {
+            # changing layer
+            $extruded_on_this_layer = 0;
+        } elsif ($info->{extruding} && $info->{dist_XY}) {
+            $extruded_on_this_layer = 1;
+        } elsif ($info->{retracting} && $info->{dist_XY} > 0) {
             $have_wipe = 1;
+            $wiping_on_new_layer = 1 if !$extruded_on_this_layer;
             my $move_time = $info->{dist_XY} / ($args->{F} // $self->F);
             push @retract_speeds, abs($info->{dist_E}) / $move_time;
         }
@@ -39,6 +49,7 @@ use Slic3r::Test;
     
     ok $have_wipe, "wipe";
     ok !defined (first { abs($_ - $config->retract_speed->[0]*60) < 5 } @retract_speeds), 'wipe moves don\'t retract faster than configured speed';
+    ok !$wiping_on_new_layer, 'no wiping after layer change';
 }
 
 {