diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
deleted file mode 100644
index 6c5bc61cbe..0000000000
--- a/.gitlab-ci.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-image: registry.gitlab.com/ultimaker/cura/cura-build-environment:centos7
-
-stages:
-  - build
-
-build and test linux:
-  stage: build
-  tags:
-    - cura
-    - docker
-    - linux
-  script:
-    - docker/build.sh
-  artifacts:
-    paths:
-      - build
diff --git a/cura/Machines/MachineNode.py b/cura/Machines/MachineNode.py
index 92f71b409b..cee71160d2 100644
--- a/cura/Machines/MachineNode.py
+++ b/cura/Machines/MachineNode.py
@@ -162,6 +162,7 @@ class MachineNode(ContainerNode):
         container_registry = ContainerRegistry.getInstance()
         if not self.has_variants:
             self.variants["empty"] = VariantNode("empty_variant", machine = self)
+            self.variants["empty"].materialsChanged.connect(self.materialsChanged)
         else:
             # Find all the variants for this definition ID.
             variants = container_registry.findInstanceContainersMetadata(type = "variant", definition = self.container_id, hardware_type = "nozzle")
diff --git a/cura/Machines/VariantNode.py b/cura/Machines/VariantNode.py
index c9e3ec4913..550b5881a3 100644
--- a/cura/Machines/VariantNode.py
+++ b/cura/Machines/VariantNode.py
@@ -167,15 +167,21 @@ class VariantNode(ContainerNode):
         # Search for any submaterials from that base file that are still left.
         materials_same_base_file = ContainerRegistry.getInstance().findContainersMetadata(base_file = base_file)
         if materials_same_base_file:
-            most_specific_submaterial = materials_same_base_file[0]
+            most_specific_submaterial = None
             for submaterial in materials_same_base_file:
                 if submaterial["definition"] == self.machine.container_id:
-                    if most_specific_submaterial["definition"] == "fdmprinter":
+                    if submaterial.get("variant_name", "empty") == self.variant_name:
                         most_specific_submaterial = submaterial
-                    if most_specific_submaterial.get("variant_name", "empty") == "empty" and submaterial.get("variant_name", "empty") == self.variant_name:
+                        break  # most specific match possible
+                    if submaterial.get("variant_name", "empty") == "empty":
                         most_specific_submaterial = submaterial
-            self.materials[base_file] = MaterialNode(most_specific_submaterial["id"], variant = self)
-            self.materialsChanged.emit(self.materials[base_file])
+
+            if most_specific_submaterial is None:
+                Logger.log("w", "Material %s removed, but no suitable replacement found", base_file)
+            else:
+                Logger.log("i", "Material %s (%s) overridden by %s", base_file, self.variant_name, most_specific_submaterial.get("id"))
+                self.materials[base_file] = MaterialNode(most_specific_submaterial["id"], variant = self)
+                self.materialsChanged.emit(self.materials[base_file])
 
         if not self.materials:  # The last available material just got deleted and there is nothing with the same base file to replace it.
             self.materials["empty_material"] = MaterialNode("empty_material", variant = self)
diff --git a/cura/UI/PrintInformation.py b/cura/UI/PrintInformation.py
index abf1083836..e33ab13b69 100644
--- a/cura/UI/PrintInformation.py
+++ b/cura/UI/PrintInformation.py
@@ -298,9 +298,7 @@ class PrintInformation(QObject):
 
         # Only update the job name when it's not user-specified.
         if not self._is_user_specified_job_name:
-            if self._pre_sliced:
-                self._job_name = catalog.i18nc("@label", "Pre-sliced file {0}", base_name)
-            elif self._application.getInstance().getPreferences().getValue("cura/jobname_prefix"):
+            if self._application.getInstance().getPreferences().getValue("cura/jobname_prefix") and not self._pre_sliced:
                 # Don't add abbreviation if it already has the exact same abbreviation.
                 if base_name.startswith(self._abbr_machine + "_"):
                     self._job_name = base_name
diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index 1c84e99d24..394342a316 100644
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -2073,6 +2073,36 @@
                             "settable_per_mesh": true
                         }
                     }
+                },
+                "skin_edge_support_thickness":
+                {
+                    "label": "Skin Edge Support Thickness",
+                    "description": "The thickness of the extra infill that supports skin edges.",
+                    "unit": "mm",
+                    "default_value": 0.8,
+                    "minimum_value": "0",
+                    "maximum_value": "machine_height",
+                    "type": "float",
+                    "value": "0",
+                    "comment": "This was put at 0 to keep the default behaviour the same, but in the original PR the 'value' was: resolveOrValue('infill_sparse_thickness') * (4 if infill_sparse_density < 12.5 else (3 if infill_sparse_density < 25 else (2 if infill_sparse_density < 50 else 1)))",
+                    "limit_to_extruder": "infill_extruder_nr",
+                    "enabled": "infill_sparse_density > 0",
+                    "settable_per_mesh": true,
+                    "children":
+                    {
+                         "skin_edge_support_layers":
+                         {
+                              "label": "Skin Edge Support Layers",
+                              "description": "The number of infill layers that supports skin edges.",
+                              "default_value": 4,
+                              "minimum_value": "0",
+                              "type": "int",
+                              "value": "math.ceil(round(skin_edge_support_thickness / resolveOrValue('infill_sparse_thickness'), 4))",
+                              "limit_to_extruder": "infill_extruder_nr",
+                              "enabled": "infill_sparse_density > 0",
+                              "settable_per_mesh": true
+                         }
+                    }
                 }
             }
         },
diff --git a/resources/setting_visibility/expert.cfg b/resources/setting_visibility/expert.cfg
index 2b9ad362fc..7b24934b0d 100644
--- a/resources/setting_visibility/expert.cfg
+++ b/resources/setting_visibility/expert.cfg
@@ -101,6 +101,8 @@ bottom_skin_expand_distance
 max_skin_angle_for_expansion
 min_skin_width_for_expansion
 infill_randomize_start_location
+skin_edge_support_thickness
+skin_edge_support_layers
 
 [material]
 default_material_print_temperature