Do not crash if mms part data is not exist

[keydon3]

When i export messages with "Include (encoded) binary MMS data", i get fatal error:

07-30 22:41:37.675  7582  7582 D MediaScannerReceiver: action: android.intent.action.MEDIA_SCANNER_SCAN_FILE path: /storage/emulated/0/backup/messages.json
07-30 22:41:37.715  5454  5454 E AndroidRuntime: FATAL EXCEPTION: main
07-30 22:41:37.715  5454  5454 E AndroidRuntime: Process: com.github.tmo1.sms_ie, PID: 5454
07-30 22:41:37.715  5454  5454 E AndroidRuntime: java.io.FileNotFoundException: open failed: ENOENT (No such file or directory)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at android.database.DatabaseUtils.readExceptionWithFileNotFoundExceptionFromParcel(DatabaseUtils.java:144)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at android.content.ContentProviderProxy.openTypedAssetFile(ContentProviderNative.java:698)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at android.content.ContentResolver.openTypedAssetFileDescriptor(ContentResolver.java:1410)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:1247)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at android.content.ContentResolver.openInputStream(ContentResolver.java:967)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at com.github.tmo1.sms_ie.ImportExportKt.mmsToJSON(ImportExport.kt:374)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at com.github.tmo1.sms_ie.ImportExportKt.access$mmsToJSON(ImportExport.kt:1)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at com.github.tmo1.sms_ie.ImportExportKt$mmsToJSON$1.invokeSuspend(Unknown Source:17)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
07-30 22:41:37.715  5454  5454 E AndroidRuntime:        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)
07-30 22:41:37.719  1243  2063 W ActivityManager:   Force finishing activity com.github.tmo1.sms_ie/.MainActivity
07-30 22:41:37.723  1243  2063 E LightsService: Light requested not available on this device. 2
07-30 22:41:37.726  1243  2063 W ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:966 com.android.server.am.AppErrors.crashApplicationInner:393 com.android.server.am.AppErrors.crashApplication:321 com.android.server.am.ActivityManagerService.handleApplicationCrashInner:14489 com.android.server.am.ActivityManagerService.handleApplicationCrash:14471 
07-30 22:41:37.728  1243  1262 I ActivityManager: Showing crash dialog for package com.github.tmo1.sms_ie u0

Tail in messages.json:

    "parts": [
      {
        "_id": "6",
        "mid": "5",
        "seq": "-1",
        "ct": "application/smil",
        "cid": "<smil>",
        "cl": "smil.xml",
        "text": "<smil>...</smil>"
      },
      {
        "_id": "7",
        "mid": "5",
        "seq": "0",
        "ct": "image/jpeg",
        "cid": "<image000000>",
        "cl": "image000000.jpg",
        "_data": "/data/user_de/0/com.android.providers.telephony/app_parts/PART_1617028091818_image000000.jpg"

Probably it's because the file doesn't exist:

/data/user_de/0/com.android.providers.telephony/app_parts # ls PART_1617028091818_image000000.jpg
ls: PART_1617028091818_image000000.jpg: No such file or directory

Without "Include (encoded) binary MMS data" all works fine.

[tmo1]

Thank you for reporting this. I'm not sure why Android is providing us with the name of a non-existent file, but perhaps we need to add some sort of null check to work around this. Is this a normal Android system, or have you done low-level manipulation of the filesystem, perhaps deleting the JPG file in question?

[keydon3]

Is this a normal Android system, or have you done low-level manipulation of the filesystem, perhaps deleting the JPG file in question?

I didn't do any low-level manipulations and didn't delete the JPG file. But I can't guarantee that some software didn't. I'm using a custom build of android (crDroid 4.7 on android 8.1.0), but I will assume that it works like a "normal" android.

[tmo1]

Thank you. I should probably add a check for problems, even if I don't understand why they would occur :)

[tmo1]

I've attached a patched version of the app that should catch and log any exceptions thrown when trying to access MMS binary message parts and then continue with the export. Please test it and report back here, if you can.
catch-mms-part-access-exceptions.zip

[keydon3]

catch-mms-part-access-exceptions.zip perfectly works without any errors

[tmo1]

catch-mms-part-access-exceptions.zip perfectly works without any errors

Thank you! Closing.

[Edit:] It's this commit (below in the thread) that fixes the problem.