StringIndexOutOfBoundsException: String index out of range: -23

[sentry]

Sentry Issue: WORDPRESS-ANDROID-1219

StringIndexOutOfBoundsException: String index out of range: -23
    at org.wordpress.android.ui.stories.SaveStoryGutenbergBlockUseCase.findAllStoryBlocksInPostAndPerformOnEachMediaFilesJson(SaveStoryGutenbergBlockUseCase.kt:105)
    at org.wordpress.android.ui.stories.SaveStoryGutenbergBlockUseCase.replaceLocalMediaIdsWithRemoteMediaIdsInPost(SaveStoryGutenbergBlockUseCase.kt:118)
    at org.wordpress.android.ui.uploads.MediaUploadReadyProcessor.replaceMediaFileWithUrlInPost(MediaUploadReadyProcessor.java:33)
    at org.wordpress.android.ui.uploads.UploadService.updatePostWithMediaUrl(UploadService.java:626)
    at org.wordpress.android.ui.uploads.UploadService.updatePostWithCurrentlyCompletedUploads(UploadService.java:474)
...
(16 additional frame(s) were not displayed)

29 events
15 users

[designsimply]

Events in the last 90d: 103
Users affected in the last 90d: 36
_{WORDPRESS-ANDROID-1219: https://sentry.io/share/issue/6214144e465a4f4c9e2440a5ca23ef01/}

[renanferrari]

I spent some time looking into this today and even though I couldn't find the root cause of the crash, I was able to locate where it originates from and to submit a PR that should prevent it from happening again: #14185

I also managed to reproduce the crash once, but couldn't find a way to do it again after that. I'm leaving some of the steps I used when the crash happened below, so maybe someone else can put the pieces together and figure it out:

1. First, I created a draft Story post on Android and then edited it on the web by adding/removing frames from it.
2. Back on Android, I opened the draft post and edited it again.
3. When I tapped the back button to go back to the Drafts screen, the post started updating but suddenly stopped and was then labeled as "Local changes".
4. When I selected the post again to edit it, the app crashed.

Although I wasn't able to validate this, my best guess is that the block gets corrupted somehow and the findAllStoryBlocksInPostAndPerformOnEachMediaFilesJson method fails to parse the post content.

[mzorz]

The content logging seems to have worked and we now have an occurrence of the issue with more data. Investigating this now. https://sentry.io/share/issue/43c323b5aa11414a8602541c30719d24/

[mzorz]

This is quite weird, the logs show a block that contains this:

<!-- wp:jetpack/story {"mediaFiles":[{"alt":"","caption":"","id":"204","link":"link_to_file","mime":"image/jpeg","type":"image","url":"link_to_file"}]} -->
<div class="wp-story wp-block-jetpack-story"><img data-wpid="68" src="/data/user/0/org.wordpress.android/cache/wp_story1618006190441_02052689053844467476.jpg" class="uploading size-full" /></div>
<!-- /wp:jetpack/story -->

(the link_to_file is an actual, well formatted http link to a Story slide).

Here there's this part, that seems to be an image being uploaded, which does not belong to the Story block:

<img data-wpid="68" src="/data/user/0/org.wordpress.android/cache/wp_story1618006190441_02052689053844467476.jpg" class="uploading size-full" />

Continuing to look into this, trying to find an explanation and a way to reproduce.

[mzorz]

the data-wpid attribute is used by Aztec to tag images being uploaded.

The only thing I can think of right now is that the user:

1. created the Story
2. but then somehow edited the Post with Aztec
3. added an image and tried to start an upload

Looking now to see if they can set back to Aztec or maybe there's a flaw in how we decide to open Aztec or Gutenberg. Will report back.

[sentry]

Sentry issue: WORDPRESS-ANDROID-127S