[BUG] Crash when mimetype is empty

[theScrabi]

When the server returns an empty mimetype on a PROPFIND, the app will crash because it tries to figure out weather the current resource element is a direcotry or not by comparing the returned mimetype against the string DIR. However since the returned mimetype is null the app crashes:

java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference
        at com.owncloud.android.utils.FileStorageUtils.createOCFileFromRemoteFile(FileStorageUtils.java:108)
        at com.owncloud.android.operations.SynchronizeFolderOperation.mergeRemoteFolder(SynchronizeFolderOperation.java:337)
        at com.owncloud.android.operations.SynchronizeFolderOperation.run(SynchronizeFolderOperation.java:225)
        at com.owncloud.android.lib.common.operations.RemoteOperation.runOperation(RemoteOperation.java:240)
        at com.owncloud.android.lib.common.operations.RemoteOperation.execute(RemoteOperation.java:205)
        at com.owncloud.android.operations.common.SyncOperation.execute(SyncOperation.java:87)
        at com.owncloud.android.operations.RefreshFolderOperation.run(RefreshFolderOperation.java:143)
        at com.owncloud.android.lib.common.operations.RemoteOperation.runOperation(RemoteOperation.java:240)
        at com.owncloud.android.lib.common.operations.RemoteOperation.run(RemoteOperation.java:259)

This does normally not happen as the server should always send a mimetype, however if he does not we aparently must be prepared.

Steps to reproduce:

1. Use mitm proxy and intercept response
2. Pull down to refresh inside files view
3. When response of propfind is send remove content inside the <contenttype></contenttype> tag

This may sometimes happen when a user creates a file without file ending, or if a file without file ending is shared.

fix: #2986

[michaelstingl]

@jesmrec can you try to reproduce?

[jesmrec]

Reopened because #2977 (comment)

But, more info is needed. Not able to reproduce.

@candrea21 could you provide extra info?

[candrea21]

Same happens as already reported. When opening a folder containing an "exotic" file, as for example "test.db" on a WebDAV storage, the app crashes.

[jesmrec]

Could you add logs?

i can not reproduce the problem after using a WebDAV storage with multiple file names....

[candrea21]

D: 2021-06-01 13:19:14:015(OCFile.java:404) .setFileName()OCFile name changing from /mydir/test/testmime/
D: 2021-06-01 13:19:14:016(OCFile.java:413) .setFileName()OCFile name changed to /mydir/test/testmime/
D: 2021-06-01 13:19:14:017(FileDataStorageManager.kt:421) .saveFolder()Saving folder /mydir/test/ with 11 children and 0 files to remove
D: 2021-06-01 13:19:14:050(SingleSessionManager.java:74) .getClientFor()getClientFor starting 
V: 2021-06-01 13:19:14:051(SingleSessionManager.java:101) .getClientFor()reusing client for account myusername@/myowncloud.com/owncloud
D: 2021-06-01 13:19:14:053(SingleSessionManager.java:138) .getClientFor()getClientFor 
D: 2021-06-01 13:19:14:055(ThumbnailsCacheManager.java:282) $ThumbnailGenerationTask.doOCFileInBackground()URI: https://myowncloud.com/owncloud/remote.php/dav/files/myusername/mydir/test/testmime/test.db?x=256&y=256&c=&preview=1
D: 2021-06-01 13:19:14:059(OwnCloudClient.java:103) .executeHttpMethod()Executing in request with id bd445dfb-17fb-41b3-ac0f-5680dc99489e
D: 2021-06-01 13:19:14:063(LogBuilder.kt:38) .logHttp()[Network, request] [info] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Type: GET URL: https://myowncloud.com/owncloud/remote.php/dav/files/myusername/mydir/test/testmime/test.db?x=256&y=256&c=&preview=1
D: 2021-06-01 13:19:14:064(LogBuilder.kt:38) .logHttp()[Network, request] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] X-Request-ID: bd445dfb-17fb-41b3-ac0f-5680dc99489e
D: 2021-06-01 13:19:14:066(LogBuilder.kt:38) .logHttp()[Network, request] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] User-Agent: Mozilla/5.0 (Android) ownCloud-android/2.18
D: 2021-06-01 13:19:14:067(LogBuilder.kt:38) .logHttp()[Network, request] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Accept-Encoding: identity
D: 2021-06-01 13:19:14:069(LogBuilder.kt:38) .logHttp()[Network, request] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Authorization: [redacted]
D: 2021-06-01 13:19:14:070(LogBuilder.kt:38) .logHttp()[Network, request] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Host: myowncloud.com
D: 2021-06-01 13:19:14:072(LogBuilder.kt:38) .logHttp()[Network, request] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Connection: Keep-Alive
D: 2021-06-01 13:19:14:073(LogBuilder.kt:38) .logHttp()[Network, request] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Cookie: oc_sessionPassphrase=TmOvDQ7GSVe%2FWtI9kxpbOLAwfqDqvf9hyWZD4%2FNvyaarmR9AF6ePifRDZM2Tz8Su%2BFhdnPG5yfnkhnFbR0IXnOAJ%2BkWNkaCF6vg5FjNw96OA94%2FZZjkcg8%2FogSvMYOhI; ocdaf4b9d284=ce77aa0caa37075fa0cf7d24652cf97d; cookie_test=test
D: 2021-06-01 13:19:14:075(LogBuilder.kt:38) .logHttp()[Network, request] [body] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Empty body
D: 2021-06-01 13:19:14:192(FileDataStorageManager.kt:533) .saveFolder()Sending 12 operations to FileContentProvider
D: 2021-06-01 13:19:14:193(FileContentProvider.kt:487) .applyBatch()applying batch in provider com.owncloud.android.providers.FileContentProvider@1e24ab3 (temporary: false)
D: 2021-06-01 13:19:14:266(FileContentProvider.kt:502) .applyBatch()applied batch in provider com.owncloud.android.providers.FileContentProvider@1e24ab3
V: 2021-06-01 13:19:14:268(SynchronizeFolderOperation.java:475) .syncContents()Starting content synchronization... 
D: 2021-06-01 13:19:14:269(RefreshFolderOperation.java:231) .sendLocalBroadcast()Send broadcast com.owncloud.android.operations.RefreshFolderOperation.EVENT_SINGLE_FOLDER_CONTENTS_SYNCED
D: 2021-06-01 13:19:14:271(OwnCloudClient.java:103) .executeHttpMethod()Executing in request with id 8b0771b7-415e-418a-8ad3-601d44b95074
D: 2021-06-01 13:19:14:274(LogBuilder.kt:38) .logHttp()[Network, request] [info] [8b0771b7-415e-418a-8ad3-601d44b95074] Type: GET URL: https://myowncloud.com/owncloud/ocs/v2.php/apps/files_sharing/api/v1/shares?path=%2Fmydir%2Ftest%2F&reshares=true&subfiles=true
D: 2021-06-01 13:19:14:275(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] OCS-APIREQUEST: true
D: 2021-06-01 13:19:14:277(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-Request-ID: 8b0771b7-415e-418a-8ad3-601d44b95074
D: 2021-06-01 13:19:14:278(LogBuilder.kt:38) .logHttp()[Network, response] [info] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Code: 404  Message: Not Found IsSuccessful: false
D: 2021-06-01 13:19:14:278(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] User-Agent: Mozilla/5.0 (Android) ownCloud-android/2.18
D: 2021-06-01 13:19:14:281(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Server: nginx
D: 2021-06-01 13:19:14:281(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Accept-Encoding: identity
D: 2021-06-01 13:19:14:282(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Authorization: [redacted]
D: 2021-06-01 13:19:14:282(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Date: Tue, 01 Jun 2021 11:19:14 GMT
D: 2021-06-01 13:19:14:282(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Host: myowncloud.com
D: 2021-06-01 13:19:14:283(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Content-Type: application/xml; charset=utf-8
D: 2021-06-01 13:19:14:283(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Connection: Keep-Alive
D: 2021-06-01 13:19:14:283(LogBuilder.kt:38) .logHttp()[Network, request] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Cookie: oc_sessionPassphrase=TmOvDQ7GSVe%2FWtI9kxpbOLAwfqDqvf9hyWZD4%2FNvyaarmR9AF6ePifRDZM2Tz8Su%2BFhdnPG5yfnkhnFbR0IXnOAJ%2BkWNkaCF6vg5FjNw96OA94%2FZZjkcg8%2FogSvMYOhI; ocdaf4b9d284=ce77aa0caa37075fa0cf7d24652cf97d; cookie_test=test
D: 2021-06-01 13:19:14:283(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Transfer-Encoding: chunked
D: 2021-06-01 13:19:14:284(LogBuilder.kt:38) .logHttp()[Network, request] [body] [8b0771b7-415e-418a-8ad3-601d44b95074] Empty body
D: 2021-06-01 13:19:14:284(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Connection: keep-alive
D: 2021-06-01 13:19:14:286(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Vary: Accept-Encoding
D: 2021-06-01 13:19:14:287(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Expires: Thu, 19 Nov 1981 08:52:00 GMT
D: 2021-06-01 13:19:14:288(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Cache-Control: no-store, no-cache, must-revalidate
D: 2021-06-01 13:19:14:290(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Pragma: no-cache
D: 2021-06-01 13:19:14:291(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Content-Security-Policy: default-src 'none';
D: 2021-06-01 13:19:14:293(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] X-Content-Type-Options: nosniff
D: 2021-06-01 13:19:14:294(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] X-XSS-Protection: 0
D: 2021-06-01 13:19:14:295(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] X-Robots-Tag: none
D: 2021-06-01 13:19:14:297(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] X-Frame-Options: SAMEORIGIN
D: 2021-06-01 13:19:14:298(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] X-Download-Options: noopen
D: 2021-06-01 13:19:14:299(LogBuilder.kt:38) .logHttp()[Network, response] [header] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] X-Permitted-Cross-Domain-Policies: none
D: 2021-06-01 13:19:14:301(LogBuilder.kt:38) .logHttp()[Network, response] [body] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Length: -1 byte body
D: 2021-06-01 13:19:14:303(LogBuilder.kt:38) .logHttp()[Network, response] [body] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] Type: application/xml; charset=utf-8
D: 2021-06-01 13:19:14:304(LogBuilder.kt:38) .logHttp()[Network, response] [body] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] --> Body start for response
D: 2021-06-01 13:19:14:306(LogBuilder.kt:38) .logHttp()[Network, response] [body] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] <?xml version="1.0" encoding="utf-8"?>
<d:error xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns">
  <s:exception>Sabre\DAV\Exception\NotFound</s:exception>
  <s:message/>
</d:error>
D: 2021-06-01 13:19:14:307(LogBuilder.kt:38) .logHttp()[Network, response] [body] [bd445dfb-17fb-41b3-ac0f-5680dc99489e] <-- Body end for response -- Omitted: 0 bytes
D: 2021-06-01 13:19:14:656(LogBuilder.kt:38) .logHttp()[Network, response] [info] [8b0771b7-415e-418a-8ad3-601d44b95074] Code: 200  Message: OK IsSuccessful: true
D: 2021-06-01 13:19:14:658(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Server: nginx
D: 2021-06-01 13:19:14:660(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Date: Tue, 01 Jun 2021 11:19:14 GMT
D: 2021-06-01 13:19:14:662(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Content-Type: application/xml; charset=utf-8
D: 2021-06-01 13:19:14:663(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Content-Length: 187
D: 2021-06-01 13:19:14:665(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Connection: keep-alive
D: 2021-06-01 13:19:14:667(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Vary: Accept-Encoding
D: 2021-06-01 13:19:14:668(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Expires: Thu, 19 Nov 1981 08:52:00 GMT
D: 2021-06-01 13:19:14:670(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Pragma: no-cache
D: 2021-06-01 13:19:14:672(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Cache-Control: no-cache, no-store, must-revalidate
D: 2021-06-01 13:19:14:674(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] Content-Security-Policy: default-src 'none';manifest-src 'self';script-src 'self' 'unsafe-eval';style-src 'self' 'unsafe-inline';img-src 'self' data: blob:;font-src 'self';connect-src 'self';media-src 'self' http://*:* https://*:*
D: 2021-06-01 13:19:14:675(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-Content-Type-Options: nosniff
D: 2021-06-01 13:19:14:677(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-XSS-Protection: 0
D: 2021-06-01 13:19:14:678(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-Robots-Tag: none
D: 2021-06-01 13:19:14:681(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-Frame-Options: SAMEORIGIN
D: 2021-06-01 13:19:14:682(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-Download-Options: noopen
D: 2021-06-01 13:19:14:683(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-Permitted-Cross-Domain-Policies: none
D: 2021-06-01 13:19:14:684(LogBuilder.kt:38) .logHttp()[Network, response] [header] [8b0771b7-415e-418a-8ad3-601d44b95074] X-Powered-By: PleskLin
D: 2021-06-01 13:19:14:685(LogBuilder.kt:38) .logHttp()[Network, response] [body] [8b0771b7-415e-418a-8ad3-601d44b95074] Length: 187 byte body
D: 2021-06-01 13:19:14:686(LogBuilder.kt:38) .logHttp()[Network, response] [body] [8b0771b7-415e-418a-8ad3-601d44b95074] Type: application/xml; charset=utf-8
D: 2021-06-01 13:19:14:686(LogBuilder.kt:38) .logHttp()[Network, response] [body] [8b0771b7-415e-418a-8ad3-601d44b95074] --> Body start for response
D: 2021-06-01 13:19:14:687(LogBuilder.kt:38) .logHttp()[Network, response] [body] [8b0771b7-415e-418a-8ad3-601d44b95074] <?xml version="1.0"?>
<ocs>
 <meta>
  <status>ok</status>
  <statuscode>200</statuscode>
  <message/>
  <totalitems></totalitems>
  <itemsperpage></itemsperpage>
 </meta>
 <data/>
</ocs>
D: 2021-06-01 13:19:14:688(LogBuilder.kt:38) .logHttp()[Network, response] [body] [8b0771b7-415e-418a-8ad3-601d44b95074] <-- Body end for response -- Omitted: 0 bytes
D: 2021-06-01 13:19:14:689(GetRemoteSharesForFileOperation.kt:92) .run()Got 0 shares
D: 2021-06-01 13:19:15:136(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:194(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:261(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:325(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:386(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:447(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:506(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:563(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:623(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:682(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:740(FileDataStorageManager.kt:383) .saveFile()Rows updated: 1
D: 2021-06-01 13:19:15:741(RefreshFolderOperation.java:231) .sendLocalBroadcast()Send broadcast com.owncloud.android.operations.RefreshFolderOperation.EVENT_SINGLE_FOLDER_SHARES_SYNCED