SUSE DM: add special case configuring autologin in sysconfig (openSUSE)

FIXES #582

src/modules/displaymanager/displaymanager.conf

@@ -20,3 +20,7 @@ displaymanagers:
 #display manager are set up correctly. This is normally done by the distribution
 #packages, and best left to them. Therefore, it is disabled by default.
 basicSetup: false
+
+#If true, setup autologin for openSUSE. This only makes sense on openSUSE
+#derivatives or other systems where /etc/sysconfig/displaymanager exists.
+sysconfigSetup: false

src/modules/displaymanager/main.py

@@ -355,6 +355,18 @@ def set_autologin(username,
         with open(sddm_conf_path, 'w') as sddm_config_file:
             sddm_config.write(sddm_config_file, space_around_delimiters=False)
 
+    if "sysconfig" == displaymanager:
+        dmauto = "DISPLAYMANAGER_AUTOLOGIN"
+
+        os.system(
+            "sed -i -e 's|^{!s}=.*|{!s}=\"{!s}\"|' "
+            "{!s}/etc/sysconfig/displaymanager".format(
+                            dmauto, dmauto,
+                            username if do_autologin else "",
+                            root_mount_point
+                            )
+            )
+
     return None
 
 
@@ -662,6 +674,11 @@ def run():
                         )
         if dm_message is not None:
             dm_setup_message.append("{!s}: {!s}".format(*dm_message))
+
+    if ("sysconfigSetup" in libcalamares.job.configuration
+            and libcalamares.job.configuration["sysconfigSetup"]):
+        set_autologin(username, "sysconfig", None, root_mount_point)
+
     if dm_setup_message:
         return ("Display manager configuration was incomplete",
                 "\n".join(dm_setup_message))