BatchOperation: explicitly allow null values

src/main/java/at/bitfire/ical4android/AndroidEvent.kt

@@ -819,7 +819,7 @@ abstract class AndroidEvent(
     }
 
     protected open fun insertReminder(batch: BatchOperation, idxEvent: Int, alarm: VAlarm) {
-        val builder =BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(Reminders.CONTENT_URI))
+        val builder = BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(Reminders.CONTENT_URI))
 
         val method = when (alarm.action?.value?.toUpperCase(Locale.US)) {
             Action.DISPLAY.value,
@@ -841,7 +841,7 @@ abstract class AndroidEvent(
     }
 
     protected open fun insertAttendee(batch: BatchOperation, idxEvent: Int, attendee: Attendee) {
-        val builder =BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(Attendees.CONTENT_URI))
+        val builder = BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(Attendees.CONTENT_URI))
 
         val member = attendee.calAddress
         if (member.scheme.equals("mailto", true))
@@ -883,7 +883,7 @@ abstract class AndroidEvent(
                     // drop occurrences of EXT_CATEGORIES_SEPARATOR in category names
                     category.filter { it != EXT_CATEGORIES_SEPARATOR }
                 }
-        val builder =BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(ExtendedProperties.CONTENT_URI))
+        val builder = BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(ExtendedProperties.CONTENT_URI))
                 .withValue(ExtendedProperties.NAME, EXT_CATEGORIES)
                 .withValue(ExtendedProperties.VALUE, rawCategories)
 
@@ -897,7 +897,7 @@ abstract class AndroidEvent(
             return
         }
 
-        val builder =BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(ExtendedProperties.CONTENT_URI))
+        val builder = BatchOperation.CpoBuilder.newInsert(calendar.syncAdapterURI(ExtendedProperties.CONTENT_URI))
                 .withValue(ExtendedProperties.NAME, UnknownProperty.CONTENT_ITEM_TYPE)
                 .withValue(ExtendedProperties.VALUE, UnknownProperty.toJsonString(property))
 

src/main/java/at/bitfire/ical4android/BatchOperation.kt

@@ -134,7 +134,7 @@ class BatchOperation(
         var selection: String? = null
         var selectionArguments: Array<String>? = null
 
-        val values = mutableMapOf<String, Any>()
+        val values = mutableMapOf<String, Any?>()
         val valueBackrefs = mutableMapOf<String, Int>()
 
 
@@ -156,10 +156,7 @@ class BatchOperation(
         }
 
         fun withValue(key: String, value: Any?): CpoBuilder {
-            if (value != null)
-                values[key] = value
-            else
-                values -= key
+            values[key] = value
             return this
         }