savegames array itself is correctly sorted but the UI is not and lastmodified time is also not written

src/net/torvald/terrarum/savegame/DiskSkimmer.kt

@@ -92,7 +92,7 @@ removefile:
         val fis = FileInputStream(diskFile)
         var currentPosition = fis.skip(VirtualDisk.HEADER_SIZE) // skip disk header
 
-        println("[DiskSkimmer] loading the diskfile ${diskFile.canonicalPath}")
+//        println("[DiskSkimmer] loading the diskfile ${diskFile.canonicalPath}")
 
         fun skipRead(bytes: Long) {
             currentPosition += fis.skip(bytes)
@@ -353,13 +353,44 @@ removefile:
         return bytes.toCanonicalString(charset)
     }
 
-    fun getLastModifiedOfFirstFile(): Long {
+    /**
+     * @return creation time of the root directory
+     */
+    fun getCreationTime(): Long {
+        val bytes = ByteArray(6)
+        fa.seek(320L)
+        fa.read(bytes)
+        return bytes.toInt48()
+    }
+
+    /**
+     * @return last modified time of the root directory
+     */
+    fun getLastModifiedTime(): Long {
         val bytes = ByteArray(6)
         fa.seek(326L)
         fa.read(bytes)
         return bytes.toInt48()
     }
 
+    /**
+     * redefines creation time of the root directory
+     */
+    fun setCreationTime(time_t: Long) {
+        val bytes = ByteArray(6)
+        fa.seek(320L)
+        fa.write(time_t.toInt48())
+    }
+
+    /**
+     * redefines last modified time of the root directory
+     */
+    fun setLastModifiedTime(time_t: Long) {
+        val bytes = ByteArray(6)
+        fa.seek(326L)
+        fa.write(time_t.toInt48())
+    }
+
     ///////////////////////////////////////////////////////
     // THESE ARE METHODS TO SUPPORT ON-LINE MODIFICATION //
     ///////////////////////////////////////////////////////

src/net/torvald/terrarum/savegame/VirtualDisk.kt

@@ -148,9 +148,15 @@ class VirtualDisk(
 
     private fun serializeEntriesOnly(): ByteArray64 {
         val buffer = ByteArray64()
+
+        // make sure to write root directory first
+        entries[0L]!!.let { rootDir ->
+            rootDir.serialize().forEach { buffer.add(it) }
+        }
         entries.forEach {
-            val serialised = it.value.serialize()
-            serialised.forEach { buffer.add(it) }
+            if (it.key != 0L) {
+                it.value.serialize().forEach { buffer.add(it) }
+            }
         }
 
         return buffer