Request change VTODO parsing errors to be non-fatal / improve logging

ccoenen

I am experiencing the same problem as described in Tasks are not synchronized: DUE must not be < DTSTART.

Sadly, I have quite a few tasks, so that going over each item one by one to find the faulty one is not practical. So right now, I’m left with no working sync.

I would like to suggest two things

Improve logging to a point where I can easily identify the faulty task. The log output could just also dump the plain text it’s trying to parse below the stack trace. That would be immensely helpful. Other helpful Solutions would be to include the faulty timestamps if it’s easier. Basically: include anything that allows me to narrow down the faulty tasks.
(From the stack trace i’m not sure it falls within the domain of DAVdroid.) I do realize that DUE < DTSTART is against the specs. Warn about it all you want. But please don’t throw everything else under the bus by throwing an exception.

Steps to reproduce

Have a VTODO on your server that has DUE < DTSTART.
Sync
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See this log message

SYNCHRONIZATION INFO
Synchronization phase: 9
Account name: ---redacted---
Authority: org.dmfs.tasks

EXCEPTION:
java.lang.IllegalArgumentException: DUE must not be < DTSTART
	at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:165)
	at android.database.DatabaseUtils.readExceptionWithOperationApplicationExceptionFromParcel(DatabaseUtils.java:158)
	at android.content.ContentProviderProxy.applyBatch(ContentProviderNative.java:520)
	at android.content.ContentProviderClient.applyBatch(ContentProviderClient.java:418)
	at at.bitfire.ical4android.BatchOperation.runBatch(BatchOperation.java:86)
	at at.bitfire.ical4android.BatchOperation.commit(BatchOperation.java:58)
	at at.bitfire.ical4android.AndroidTask.update(AndroidTask.java:237)
	at at.bitfire.davdroid.syncadapter.TasksSyncManager.processVTodo(TasksSyncManager.java:205)
	at at.bitfire.davdroid.syncadapter.TasksSyncManager.downloadRemote(TasksSyncManager.java:145)
	at at.bitfire.davdroid.syncadapter.SyncManager.performSync(SyncManager.java:170)
	at at.bitfire.davdroid.syncadapter.TasksSyncAdapterService$SyncAdapter.onPerformSync(TasksSyncAdapterService.java:78)
	at android.content.AbstractThreadedSyncAdapter$SyncThread.run(AbstractThreadedSyncAdapter.java:272)

SOFTWARE INFORMATION
DAVdroid version: 1.3.1-ose (116) Wed Sep 21 08:17:52 GMT+02:00 2016
Installed from: org.fdroid.fdroid
JB Workaround installed: no

CONFIGURATION
System-wide synchronization: automatically
Account: ---redacted---
  Address book sync. interval: x min
  Calendar     sync. interval: x min
  OpenTasks    sync. interval: x min
  WiFi only: x
  [CardDAV] Contact group method: CATEGORIES
            RFC 6868 encoding: x
  [CalDAV] Time range (past days): x
           Manage calendar colors: x

SQLITE DUMP
android_metadata
	|  locale |
	|  x |
----------
settings
	|  setting | value |
	|  hint_OpenTasksNotInstalled | 0 |
----------
services
	|  _id | accountName | service | principal |
	|  3 | ---redacted--- | carddav | ---redacted--- |
	|  4 | ---redacted--- | caldav | ---redacted--- |
----------
sqlite_sequence
	|  name | seq |
	|  services | 4 |
	|  collections | 52 |
	|  homesets | 11 |
----------
homesets
	|  _id | serviceID | url |
	|  10 | 4 | ---redacted--- |
	|  11 | 3 | ---redacted--- |
----------
collections
	|  _id | serviceID | url | readOnly | displayName | description | color | timezone | supportsVEVENT | supportsVTODO | sync |
	|  44 | 4 | ---redacted--- | 1 | ---redacted--- | ---redacted--- | -54 | <null> | 1 | 1 | 0 |
	|  45 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -6306073 | <null> | 1 | 1 | 1 |
	|  46 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -1146130 | <null> | 1 | 1 | 1 |
	|  47 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -16777216 | <null> | 1 | 1 | 1 |
	|  48 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -1605516 | <null> | 1 | 1 | 1 |
	|  49 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -8355840 | <null> | 1 | 1 | 1 |
	|  50 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -4989844 | <null> | 1 | 1 | 1 |
	|  51 | 4 | ---redacted--- | 1 | ---redacted--- | ---redacted--- | -32944 | <null> | 1 | 1 | 1 |
	|  52 | 3 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | <null> | <null> | <null> | <null> | 1 |
----------

SYSTEM INFORMATION
Android version: 6.0.1 (---redacted---)
Device: ---redacted---