Avoid NPE when missing DTSTART for recurring events

app/src/androidTest/kotlin/at/bitfire/davdroid/CaptureExceptionsRule.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ */
+
+package at.bitfire.davdroid
+
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+import kotlin.reflect.KClass
+
+/**
+ * Use this custom rule to ignore exceptions thrown by another rule.
+ */
+class CaptureExceptionsRule(
+    private val innerRule: TestRule,
+    private vararg val exceptionsToIgnore: KClass<out Throwable>
+) : TestRule {
+    override fun apply(base: Statement, description: Description): Statement {
+        return object : Statement() {
+            override fun evaluate() {
+                try {
+                    innerRule.apply(base, description).evaluate()
+                } catch (e: Throwable) {
+                    val shouldIgnore = exceptionsToIgnore.any { it.isInstance(e) }
+                    if (shouldIgnore)
+                        base.evaluate()
+                    else
+                        throw e
+                }
+            }
+        }
+    }
+}

app/src/androidTest/kotlin/at/bitfire/davdroid/sync/JtxSyncManagerTest.kt

@@ -0,0 +1,189 @@
+/*
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ */
+
+package at.bitfire.davdroid.sync
+
+import android.content.ContentProviderClient
+import android.content.Context
+import android.content.pm.PackageManager
+import androidx.core.content.ContextCompat
+import androidx.test.rule.GrantPermissionRule
+import at.bitfire.davdroid.CaptureExceptionsRule
+import at.bitfire.davdroid.db.Collection
+import at.bitfire.davdroid.db.Service
+import at.bitfire.davdroid.network.HttpClient
+import at.bitfire.davdroid.repository.DavServiceRepository
+import at.bitfire.davdroid.resource.LocalJtxCollection
+import at.bitfire.davdroid.resource.LocalJtxCollectionStore
+import at.bitfire.davdroid.sync.account.TestAccount
+import at.bitfire.ical4android.util.MiscUtils.closeCompat
+import at.techbee.jtx.JtxContract
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.android.testing.HiltAndroidRule
+import dagger.hilt.android.testing.HiltAndroidTest
+import okhttp3.HttpUrl.Companion.toHttpUrl
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assume.assumeTrue
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import java.io.StringReader
+import javax.inject.Inject
+
+
+/**
+ * Ensure you have jtxBoard installed on the emulator, before running these tests. Otherwise they
+ * will be skipped.
+ */
+@HiltAndroidTest
+class JtxSyncManagerTest {
+
+    @Inject
+    @ApplicationContext
+    lateinit var context: Context
+
+    @Inject
+    lateinit var httpClientBuilder: HttpClient.Builder
+
+    @Inject
+    lateinit var serviceRepository: DavServiceRepository
+
+    @Inject
+    lateinit var localJtxCollectionStore: LocalJtxCollectionStore
+
+    @Inject
+    lateinit var jtxSyncManagerFactory: JtxSyncManager.Factory
+
+    @get:Rule
+    val hiltRule = HiltAndroidRule(this)
+
+    @get:Rule
+    val permissionRule = CaptureExceptionsRule(
+        GrantPermissionRule.grant(
+            "at.techbee.jtx.permission.READ",
+            "at.techbee.jtx.permission.WRITE"
+        ),
+        SecurityException::class
+    )
+
+    private val account = TestAccount.create()
+
+    private lateinit var provider: ContentProviderClient
+    private lateinit var syncManager: JtxSyncManager
+    private lateinit var localJtxCollection: LocalJtxCollection
+
+    @Before
+    fun setUp() {
+        hiltRule.inject()
+
+        // Check jtxBoard permissions were granted (+jtxBoard is installed); skip test otherwise
+        val canRead = permissionGranted("at.techbee.jtx.permission.READ")
+        val canWrite = permissionGranted("at.techbee.jtx.permission.WRITE")
+        assumeTrue(canRead && canWrite)
+
+        // Acquire the jtx content provider
+        provider = context.contentResolver.acquireContentProviderClient(JtxContract.AUTHORITY)!!
+
+        // Create dummy dependencies
+        val service = Service(0, account.name, Service.TYPE_CALDAV, null)
+        val serviceId = serviceRepository.insertOrReplace(service)
+        val dbCollection = Collection(0, serviceId, type = Collection.TYPE_CALENDAR, url = "https://example.com".toHttpUrl())
+        localJtxCollection = localJtxCollectionStore.create(provider, dbCollection)!!
+        syncManager = jtxSyncManagerFactory.jtxSyncManager(
+            account = account,
+            extras = arrayOf(),
+            httpClient = httpClientBuilder.build(),
+            authority = JtxContract.AUTHORITY,
+            syncResult = SyncResult(),
+            localCollection = localJtxCollection,
+            collection = dbCollection
+        )
+    }
+
+    @After
+    fun tearDown() {
+        if (this::localJtxCollection.isInitialized)
+            localJtxCollectionStore.delete(localJtxCollection)
+        serviceRepository.deleteAll()
+        if (this::provider.isInitialized)
+        provider.closeCompat()
+        TestAccount.remove(account)
+    }
+
+
+    @Test
+    fun testProcessICalObject_addsVtodo() {
+        val calendar = "BEGIN:VCALENDAR\n" +
+            "PRODID:-Vivaldi Calendar V1.0//EN\n" +
+            "VERSION:2.0\n" +
+            "BEGIN:VTODO\n" +
+            "SUMMARY:Test Task (Main VTODO)\n" +
+            "DTSTAMP;VALUE=DATE-TIME:20250228T032800Z\n" +
+            "UID:47a23c66-8c1a-4b44-bbe8-ebf33f8cf80f\n" +
+            "END:VTODO\n" +
+            "END:VCALENDAR"
+
+        // Should create "demo-calendar"
+        syncManager.processICalObject("demo-calendar", "abc123", StringReader(calendar))
+
+        // Verify main VTODO is created
+        val localJtxIcalObject = localJtxCollection.findByName("demo-calendar")!!
+        assertEquals("47a23c66-8c1a-4b44-bbe8-ebf33f8cf80f", localJtxIcalObject.uid)
+        assertEquals("abc123", localJtxIcalObject.eTag)
+        assertEquals("Test Task (Main VTODO)", localJtxIcalObject.summary)
+    }
+
+    @Test
+    fun testProcessICalObject_addsRecurringVtodo_withoutDtStart() {
+        // Valid calendar example (See bitfireAT/davx5-ose#1265)
+        // Note: We don't support starting a recurrence from DUE (RFC 5545  leaves it open to interpretation)
+        val calendar = "BEGIN:VCALENDAR\n" +
+            "PRODID:-Vivaldi Calendar V1.0//EN\n" +
+            "VERSION:2.0\n" +
+            "BEGIN:VTODO\n" +
+
+            "SUMMARY:Test Task (Exception)\n" +
+            "DTSTAMP;VALUE=DATE-TIME:20250228T032800Z\n" +
+            "DUE;TZID=America/New_York:20250228T130000\n" +
+            "RECURRENCE-ID;TZID=America/New_York:20250228T130000\n" +
+            "UID:47a23c66-8c1a-4b44-bbe8-ebf33f8cf80f\n" +
+
+            "END:VTODO\n" +
+            "BEGIN:VTODO\n" +
+
+            "SUMMARY:Test Task (Main VTODO)\n" +
+            "DTSTAMP;VALUE=DATE-TIME:20250228T032800Z\n" +
+            "DUE;TZID=America/New_York:20250228T130000\n" + // Due date will NOT be assumed as start for recurrence
+            "SEQUENCE:1\n" +
+            "UID:47a23c66-8c1a-4b44-bbe8-ebf33f8cf80f\n" +
+            "RRULE:FREQ=WEEKLY;INTERVAL=1;BYDAY=FR;UNTIL=20250505T235959Z\n" +
+
+            "END:VTODO\n" +
+            "END:VCALENDAR"
+
+        // Create and store calendar
+        syncManager.processICalObject("demo-calendar", "abc123", StringReader(calendar))
+
+        // Verify main VTODO was created with RRULE present
+        val mainVtodo = localJtxCollection.findByName("demo-calendar")!!
+        assertEquals("Test Task (Main VTODO)", mainVtodo.summary)
+        assertEquals("FREQ=WEEKLY;UNTIL=20250505T235959Z;INTERVAL=1;BYDAY=FR", mainVtodo.rrule)
+
+        // Verify the RRULE exception instance was created with correct recurrence-id timezone
+        val vtodoException = localJtxCollection.findRecurInstance(
+            uid = "47a23c66-8c1a-4b44-bbe8-ebf33f8cf80f",
+            recurid = "20250228T130000"
+        )!!
+        assertEquals("Test Task (Exception)", vtodoException.summary)
+        assertEquals("America/New_York", vtodoException.recuridTimezone)
+    }
+
+
+    // helpers
+
+    private fun permissionGranted(permission: String) =
+        ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED
+
+}

app/src/main/kotlin/at/bitfire/davdroid/resource/LocalJtxCollection.kt

@@ -61,10 +61,13 @@ class LocalJtxCollection(account: Account, client: ContentProviderClient, id: Lo
     }
 
     /**
-     * Finds and returns a recurring instance of a [LocalJtxICalObject]
+     * Finds and returns a recurrence instance of a [LocalJtxICalObject]
+     * @param uid       UID of the main VTODO
+     * @param recurid   RECURRENCE-ID of the recurrence instance
+     * @return LocalJtxICalObject or null if none or multiple entries found
      */
-    fun findRecurring(uid: String, recurid: String, dtstart: Long): LocalJtxICalObject? {
-        val values = queryRecur(uid, recurid, dtstart) ?: return null
+    fun findRecurInstance(uid: String, recurid: String): LocalJtxICalObject? {
+        val values = queryRecur(uid, recurid) ?: return null
         return LocalJtxICalObject.Factory.fromProvider(this, values)
     }
 

app/src/main/kotlin/at/bitfire/davdroid/sync/JtxSyncManager.kt

@@ -6,6 +6,7 @@ package at.bitfire.davdroid.sync
 
 import android.accounts.Account
 import android.text.format.Formatter
+import androidx.annotation.OpenForTesting
 import at.bitfire.dav4jvm.DavCalendar
 import at.bitfire.dav4jvm.MultiResponseCallback
 import at.bitfire.dav4jvm.Response
@@ -148,7 +149,8 @@ class JtxSyncManager @AssistedInject constructor(
         context.getString(R.string.sync_invalid_event)
 
 
-    private fun processICalObject(fileName: String, eTag: String, reader: Reader) {
+    @OpenForTesting
+    internal fun processICalObject(fileName: String, eTag: String, reader: Reader) {
         val icalobjects: MutableList<JtxICalObject> = mutableListOf()
         try {
             // parse the reader content and return the list of ICalObjects
@@ -163,11 +165,12 @@ class JtxSyncManager @AssistedInject constructor(
 
         icalobjects.forEach { jtxICalObject ->
             // if the entry is a recurring entry (and therefore has a recurid)
-            // we udpate the existing (generated) entry
-            if(jtxICalObject.recurid != null) {
-                val local = localCollection.findRecurring(jtxICalObject.uid, jtxICalObject.recurid!!, jtxICalObject.dtstart!!)
+            // we update the existing (generated) entry
+            val recurid = jtxICalObject.recurid
+            if(recurid != null) {
+                val local = localCollection.findRecurInstance(jtxICalObject.uid, recurid)
                 SyncException.wrapWithLocalResource(local) {
-                    logger.log(Level.INFO, "Updating $fileName with recur instance ${jtxICalObject.recurid} in local list", jtxICalObject)
+                    logger.log(Level.INFO, "Updating $fileName with recur instance $recurid in local list", jtxICalObject)
                     if(local != null) {
                         local.update(jtxICalObject)
                     } else {

gradle/libs.versions.toml

@@ -20,7 +20,7 @@ androidx-test-junit = "1.2.1"
 androidx-work = "2.10.0"
 bitfire-cert4android = "701ae604eb"
 bitfire-dav4jvm = "7d0c4f6fb9"
-bitfire-ical4android = "883954c7ca"
+bitfire-ical4android = "afa7724bcb"
 bitfire-vcard4android = "ae5d609f92"
 compose-accompanist = "0.37.2"
 compose-bom = "2025.04.00"