Proper check for luksMapperName key.

src/modules/bootloader/main.py

@@ -100,7 +100,7 @@ def create_systemd_boot_conf(uuid, conf_path, kernel_line):
         if partition["fs"] == "linuxswap":
             swap_uuid = partition["uuid"]
 
-        if partition["mountPoint"] == "/" and partition["luksMapperName"]:
+        if partition["mountPoint"] == "/" and "luksMapperName" in partition:
             cryptdevice_params = [
                 "cryptdevice=UUID={!s}:{!s}".format(partition["uuid"],
                                                     partition["luksMapperName"]),

src/modules/grubcfg/main.py

@@ -50,7 +50,7 @@ def modify_grub_default(partitions, root_mount_point, distributor):
         if partition["fs"] == "linuxswap":
             swap_uuid = partition["uuid"]
 
-        if partition["mountPoint"] == "/" and partition["luksMapperName"]:
+        if partition["mountPoint"] == "/" and "luksMapperName" in partition:
             cryptdevice_params = [
                 "cryptdevice=UUID={!s}:{!s}".format(partition["uuid"],
                                                     partition["luksMapperName"]),

src/modules/mount/main.py

@@ -40,7 +40,8 @@ def mount_partitions(root_mount_point, partitions):
         if fstype == "fat16" or fstype == "fat32":
             fstype = "vfat"
 
-        if partition["luksMapperName"]:
+        if "luksMapperName" in partition:
+            libcalamares.utils.debug("about to mount {!s}".format(partition["luksMapperName"]))
             libcalamares.utils.mount(partition["luksMapperName"],
                                      mount_point,
                                      fstype,