[Bug] Very slow performance and crashes when opening a PNG image of a map in a new tab

[anotherus3r]

Steps to reproduce

1. Go to this link: https://ourworldindata.org/grapher/total-confirmed-cases-of-covid-19-per-million-people?year=2020-05-04
2. Tap the download button below the map.
3. Tap and hold on the image next to "Save as .png".
4. Tap "Open image in new tab".

Expected behavior

Opens image in new tab without any problems.

Actual behavior

Opens new tab with image, but browser slows down significantly. Closing the tab resolves performance issues.

Device information

• Android device: Huawei Mate 20, Android 10
• Fenix version: Firefox Preview Nightly 200504 06:01 (Build #21250608)

UNITO-UNDERSCORE!20200505-190914!
UNITO-UNDERSCORE!20200505-190951!

┆Issue is synchronized with this Jira Task

[eliserichards]

Possibly related to mozilla-mobile/android-components#1159

[liuche]

Added some screenshots:

• definitely blob: file type, which explains a) crash when saving image through long-press, b) "cannot download this file type"
• the new tab is a data:img/png;base64 so maybe the file is just too big? Also says the filesize is only 0.53 MB

[csadilek]

The blob: download works now, but there are two more problems here:

• Crash: Long-pressing on the map and "saving as image" actually triggers a download for the map image (a rather big data URI). The URI is part of the download object which is stored as intent extras. See also: Crash when downloading a large data URI android-components#5217

 java.lang.RuntimeException: android.os.TransactionTooLargeException: data parcel size 1486032 bytes
        at android.app.ContextImpl.startServiceCommon(ContextImpl.java:1621)
        at android.app.ContextImpl.startService(ContextImpl.java:1571)
        at android.content.ContextWrapper.startService(ContextWrapper.java:669)
        at mozilla.components.feature.downloads.manager.FetchDownloadManager.download(FetchDownloadManager.kt:8)
        at mozilla.components.feature.downloads.DownloadsFeature.access$processDownload(DownloadsFeature.kt:16)
        at mozilla.components.feature.downloads.DownloadsFeature$start$2$invokeSuspend$$inlined$collect$1.emit(Collect.kt:4)
        at mozilla.components.support.ktx.kotlinx.coroutines.flow.FlowKt$ifChanged$$inlined$filter$1$2.emit(Collect.kt:7)
        at mozilla.components.feature.downloads.DownloadsFeature$start$2$invokeSuspend$$inlined$mapNotNull$1$2.emit(Collect.kt:6)
        at kotlinx.coroutines.CoroutineScopeKt.emitAllImpl$FlowKt__ChannelsKt(CoroutineScope.kt:14)
        at kotlinx.coroutines.flow.FlowKt__ChannelsKt$emitAllImpl$1.invokeSuspend(Unknown Source:11)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:2)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:19)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

• Performance issue: When opening the data URI in a new tab (instead of saving it) we hit: [Bug] Pasting extremely-long data URI in the address bar will hang Fenix #1824 and Pasting/getting redirected to extremely-long data URI in the address bar will hang the UI android-components#5249 respectively.

[csadilek]

Thanks for filing! The performance issue is fixed now on master and will be in tomorrow's Nightly.

Let's dupe the encountered crash to mozilla-mobile/android-components#5217 which needs a bigger refactoring to work: mozilla-mobile/android-components#7050