From a688a1931e066f4bb0fe56cdd785548d0a8940fa Mon Sep 17 00:00:00 2001
From: bubnikv <bubnikv@gmail.com>
Date: Thu, 3 May 2018 18:34:43 +0200
Subject: [PATCH] Fixed a crash on some multi-material objects due to the
 reworked cooling logic.

---
 xs/src/libslic3r/GCode/CoolingBuffer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xs/src/libslic3r/GCode/CoolingBuffer.cpp b/xs/src/libslic3r/GCode/CoolingBuffer.cpp
index 683f2030d..552695204 100644
--- a/xs/src/libslic3r/GCode/CoolingBuffer.cpp
+++ b/xs/src/libslic3r/GCode/CoolingBuffer.cpp
@@ -536,7 +536,7 @@ float CoolingBuffer::calculate_layer_slowdown(std::vector<PerExtruderAdjustments
         adj.time_total  = adj.elapsed_time_total();
         // Maximum time for this extruder, when all extrusion moves are slowed down to min_extrusion_speed.
         adj.time_maximum = adj.maximum_time_after_slowdown(true);
-        if (adj.cooling_slow_down_enabled) {
+        if (adj.cooling_slow_down_enabled && adj.lines.size() > 0) {
             by_slowdown_time.emplace_back(&adj);
             if (! m_cooling_logic_proportional)
                 // sorts the lines, also sets adj.time_non_adjustable