From 8da4151c6d911e7a3772a0784939e6a7016a9973 Mon Sep 17 00:00:00 2001
From: Alessandro Ranellucci <aar@cpan.org>
Date: Sun, 28 Oct 2012 19:24:24 +0100
Subject: [PATCH] Fix regression causing skirt to be printed at Z = 0 after a
 recent commit

---
 lib/Slic3r/GCode.pm | 6 +++---
 lib/Slic3r/Print.pm | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index c1bb3e0dd..dde29a5f5 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -9,7 +9,7 @@ has 'multiple_extruders' => (is => 'ro', default => sub {0} );
 has 'layer'              => (is => 'rw');  # this is not very correct, we should replace it with explicit layer_id and avoid using $self->layer->flow at all here because it's too general
 has 'shift_x'            => (is => 'rw', default => sub {0} );
 has 'shift_y'            => (is => 'rw', default => sub {0} );
-has 'z'                  => (is => 'rw', default => sub {0} );
+has 'z'                  => (is => 'rw');
 has 'speed'              => (is => 'rw');
 
 has 'extruder'           => (is => 'rw');
@@ -76,7 +76,7 @@ sub move_z {
     my $gcode = "";
     $gcode .= $self->retract(move_z => $z);
     $gcode .= $self->G0(undef, $z, 0, $comment || 'move to next layer (' . $self->layer->id . ')')
-        if $self->z != $z && !$self->lifted;
+        if (!defined $self->z || $self->z != $z) && !$self->lifted;
     
     return $gcode;
 }
@@ -319,7 +319,7 @@ sub _G0_G1 {
             ($point->y * &Slic3r::SCALING_FACTOR) + $self->shift_y - $self->extruder->extruder_offset->[Y]; #**
         $self->last_pos($point);
     }
-    if (defined $z && $z != $self->z) {
+    if (defined $z && (!defined $self->z || $z != $self->z)) {
         $self->z($z);
         $gcode .= sprintf " Z%.${dec}f", $z;
     }
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 8cf66cc8a..023a649fc 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -709,6 +709,8 @@ sub write_gcode {
         if ($skirt_done < $Slic3r::Config->skirt_height) {
             $gcodegen->shift_x($shift[X]);
             $gcodegen->shift_y($shift[Y]);
+            $gcode .= $gcodegen->set_extruder($self->extruders->[0]);  # move_z requires extruder
+            $gcode .= $gcodegen->move_z($gcodegen->layer->print_z);
             $gcode .= $gcodegen->set_acceleration($Slic3r::Config->perimeter_acceleration);
             # skip skirt if we have a large brim
             if ($layer_id < $Slic3r::Config->skirt_height) {
@@ -723,6 +725,7 @@ sub write_gcode {
         
         # extrude brim
         if ($layer_id == 0 && !$brim_done) {
+            $gcode .= $gcodegen->move_z($gcodegen->layer->print_z);
             $gcode .= $gcodegen->set_extruder($self->extruders->[$Slic3r::Config->support_material_extruder-1]);
             $gcodegen->shift_x($shift[X]);
             $gcodegen->shift_y($shift[Y]);