Do not remove broken WMS layers if during packaging

Sometimes online WMS layers are not accessible because of multiple reasons:
- temporary network/server error
- firewall
- network access
- etc

Just ignore these layers on the server side and don't remove them.

libqfieldsync/layer.py

@@ -113,6 +113,7 @@ class PackagePreventionReason(Enum):
         INVALID = 1
         UNSUPPORTED_DATASOURCE = 2
         LOCALIZED_PATH = 3
+        INVALID_REMOTE_RASTER_LAYER = 4
 
     REASONS_TO_REMOVE_LAYER = (
         PackagePreventionReason.INVALID,
@@ -882,6 +883,13 @@ def is_localized_path(self) -> bool:
 
         return path.startswith("localized:")
 
+    @property
+    def is_remote_raster_layer(self) -> bool:
+        if self.layer.dataProvider() and self.layer.dataProvider().name() == "wms":
+            return True
+
+        return False
+
     @property
     def package_prevention_reasons(
         self,
@@ -895,6 +903,11 @@ def package_prevention_reasons(
         # do not package the layers within localized paths (stored outside project dir and shared among multiple projects)
         if self.is_localized_path:
             reasons.append(LayerSource.PackagePreventionReason.LOCALIZED_PATH)
+        # sometimes the remote layers are inaccessible from the current network, but we should spare them from removal
+        elif not self.layer.isValid() and self.is_remote_raster_layer:
+            reasons.append(
+                LayerSource.PackagePreventionReason.INVALID_REMOTE_RASTER_LAYER
+            )
         # remove invalid layers from the packaged project
         # NOTE localized layers will be always invalid on QFieldCloud
         elif not self.layer.isValid():
@@ -1082,7 +1095,7 @@ def convert_to_gpkg(self, target_path):
             options = QgsVectorFileWriter.SaveVectorOptions()
             options.fileEncoding = "UTF-8"
             options.driverName = "GPKG"
-            (error, returned_dest_file) = QgsVectorFileWriter.writeAsVectorFormatV2(
+            (error, returned_dest_file) = QgsVectorFileWriter.writeAsVectorFormatV3(
                 source_layer, dest_file, QgsCoordinateTransformContext(), options
             )
             if error != QgsVectorFileWriter.NoError:

libqfieldsync/project_checker.py

@@ -388,6 +388,15 @@ def check_layer_package_prevention(
 
                 if reason == LayerSource.PackagePreventionReason.INVALID:
                     reason_msgs.append(self.tr("The layer is invalid!"))
+                elif (
+                    reason
+                    == LayerSource.PackagePreventionReason.INVALID_REMOTE_RASTER_LAYER
+                ):
+                    reason_msgs.append(
+                        self.tr(
+                            "The raster layer data source is not accessible from the current network!"
+                        )
+                    )
                 elif (
                     reason == LayerSource.PackagePreventionReason.UNSUPPORTED_DATASOURCE
                 ):