Bugfix: percent first layer speed was not applied over autospeed. #2945

t/speed.t

@@ -0,0 +1,53 @@
+use Test::More tests => 2;
+use strict;
+use warnings;
+
+BEGIN {
+    use FindBin;
+    use lib "$FindBin::Bin/../lib";
+    use local::lib "$FindBin::Bin/../local-lib";
+}
+
+use List::Util qw(none);
+use Slic3r;
+use Slic3r::Geometry qw(epsilon);
+use Slic3r::Test;
+
+{
+    my $config = Slic3r::Config->new_from_defaults;
+    my $test = sub {
+        my $print = Slic3r::Test::init_print('20mm_cube', config => $config);
+        my %speeds_by_z = ();  # z => []
+        Slic3r::GCode::Reader->new->parse(my $gcode = Slic3r::Test::gcode($print), sub {
+            my ($self, $cmd, $args, $info) = @_;
+
+            if ($cmd eq 'G1' && $info->{dist_E} > 0 && $info->{dist_XY} > 0) {
+                $speeds_by_z{$self->Z} //= [];
+                push @{ $speeds_by_z{$self->Z} }, $self->F/60;
+            }
+        });
+        return %speeds_by_z;
+    };
+
+    {
+        $config->set('perimeter_speed', 0);
+        $config->set('external_perimeter_speed', 0);
+        $config->set('infill_speed', 0);
+        $config->set('support_material_speed', 0);
+        $config->set('solid_infill_speed', 0);
+        $config->set('first_layer_speed', '50%');
+        $config->set('first_layer_height', 0.25);
+        my %speeds_by_z = $test->();
+        ok !!(none { $_ > $config->max_print_speed/2+&epsilon } @{ $speeds_by_z{$config->first_layer_height} }),
+            'percent first_layer_speed is applied over autospeed';
+    }
+
+    {
+        $config->set('first_layer_speed', 33);
+        my %speeds_by_z = $test->();
+        ok !!(none { $_ > $config->first_layer_speed } @{ $speeds_by_z{$config->first_layer_height} }),
+            'absolute first_layer_speed overrides autospeed';
+    }
+}
+
+__END__

xs/src/libslic3r/GCode.cpp

@@ -551,12 +551,12 @@ GCode::_extrude(ExtrusionPath path, std::string description, double speed)
             CONFESS("Invalid speed");
         }
     }
-    if (this->first_layer) {
-        speed = this->config.get_abs_value("first_layer_speed", speed);
-    }
     if (this->volumetric_speed != 0 && speed == 0) {
         speed = this->volumetric_speed / path.mm3_per_mm;
     }
+    if (this->first_layer) {
+        speed = this->config.get_abs_value("first_layer_speed", speed);
+    }
     if (this->config.max_volumetric_speed.value > 0) {
         // cap speed with max_volumetric_speed anyway (even if user is not using autospeed)
         speed = std::min(