66.0.3350.0 is not saving mhtml files, I'm confused now, please also explain, what version is WAI.

@marcin: Thanks for the report!!

Could you please help us with a sample URL, where your'e seeing this issue exactly?

Thanks!!

It was visible everywhere, and like described in #2 -> sometimes Chrome is writing mhtml, sometimes not

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Requesting UI>Browser>Downloads team for further triaging if the issue as we are unable to test the issue from our end.

Thanks!!

This is P2P Sharing being accidentally enabled for one release of Canary. We have fixed it back to be behind the flag, thanks for your patience!

Assigning this bug to Oflfine so we can verify/fix before enabling.

I regularly see this work as intended with ES File Explorer.  Marcin@, which file manager were you using?

There is another issue with FilesGo (tracked elsewhere) where the file is downloaded instead of opened, but it is properly redirected to Chrome.

marcin, if you want to re-try the repro, please turn on the following flag (it was accidentally enabled the day you found the bug, but is disabled now)
"Enables offline pages to be shared".

I'm using standard "My files" given by Samsung

With the "Enable offline pages to be shared" flag turned on, I was able to use  "My Files" on a Samsung J1, and opened the file inside chrome canary.

I'm confused:

1. I enabled flag (thx) and download few sites
2. after clicking on some of them I was asked in which browser it should be opened and Chrome Canary asked me if I want to download site again (not OK)
3. after clicking on some of them I have seen error about lack of app in the "My files" (not OK)
4. I have restarted Canary few times, download site again and I've got file in "old" style (.com.google.Chrome.someid) although flag is enabled
5. clicking on mhtml in "my files" shows info about non supported app

There is definitely something wrong with mthml support enabling and file extension handling info in OS, 66.0.3353.0

also Omnibox supports them incorrectly (https://bugs.chromium.org/p/chromium/issues/detail?id=815301)

Thanks for following up!

You are seeing a bug in step 2.  When you choose canary, the file should open in Canary instead of downloading.  We think that is a problem with newer OSs (We see it in Oreo, but not in Marshmallow or earlier, and my retest was on Lollipop. (I think I need a samsung device with "My Files" running Nougat or later to see the bug here).

Step 3 also seems like a problem. I didn't see the 'lack of app' error on my device, maybe again I need a newer device to test on.

I'm baffled about why you would see the file in "old" style, we'll have to investigate that.

Thanks again for sticking with us to clarify the problem!

thx for discussion.

I think additionally, that mhtml should be openable in Chrome even when flag is disabled.

in Pixel /Android 8.1 and 66.0.3355.0 I can open mhtml from Downloads (I'm also asked about downloading again, but... with different name: for www.chip.pl I'm asked about downloading 101, which is file ID)

Re comment 15: That is a known bug with a patch in progress:  crbug.com/813906 .  I think that is the bug you are seeing in step 2.

I'm still investigating the bug in step 3.  I was not able to repro the lack of app error from "My files" on a Samsung J1 running Lollipop.  I'll look for a more recent Samsung phone to try this.

I have not been able to repro the error in step 4 that the filename was of the form .com.google.Chrome.someid

Let's fix what can be fixed and make new round of checks. 

About .com.google.Chrome.someid - I have opened https://bugs.chromium.org/p/chromium/issues/detail?id=798225, can we maybe fix it too?

Agreed.  Let's check back in on this when  crbug.com/813906  and crbug.com/798225 are fixed, and see if that fixes the issue with My Files not finding the right app.

I tried a Samsung G5 running Lollipop with the My Files app, and I did not see the "lack of app" error when using Chrome Dev.

Android L != Android 7

Anyway, with current Canary and S7/Android 7:

0. enable new flag
1. open any page
2. make offiline version
3. go into my files and open it - opens in Chrome with question if page should be download again (not OK)
4. click back and return to my files - you have new .com.google.Chrome.someid file
5. delete all .com.google.Chrome.someid files and try to open mhtml - "lack of app" error

100% reproducible

We do still see a bug with the Samsung My Files app (Oreo 8.0) with the latest Chromium, even though ES File Explorer has no problems redirecting to Chrome.  Maybe My Files is using a whitelist, and "*.mhtml" is not on the list.

Assigning to ABoss to decide if we want to bring this up to Samsung.

Because ES File Explorer is properly offering Chrome, it looks like chrome registering in the manifest for the *.mhtml and *.mht extension was done properly.