This bug seems to have to do with redirects. In particular, long pressing on the search result (in step #5) seems to change the URL navigated to by tapping on the Google search result (in step #7)

After long pressing on the search result (and closing the dialog), tapping the link navigates to
https://www.google.ca/url?sa=t&source=web&rct=j&url=https://www.amazon.ca/&ved=0ahUKEwiPrNOf_IHVAhVI7IMKHT3UBWoQFgguMAA&usg=AFQjCNHtWpf7QVxR4Qdb7r4h-hyHKYW45g

(which is a redirect) instead of immediately navigating to

https://www.amazon.ca/

Arguably it's a bug on https://www.google.ca and not in Chrome if I understand correctly. WDYT?

On a second thought I think we could have some better handling of redirects. We could ensure we pop most recent item from the history stack if it resulted in a redirect, so that on navigating back to PWA you see last "real" entry and not this blank page this bug is talking about.

I suspect that it will be hard to detect whether the most recent item in the history stack resulted from a redirect.

- Chrome does not tag all redirects as redirects
- Chrome sometimes thinks that a single redirect chain is multiple redirect chains. This occurs when a redirect chain is composed of both HTTP 301 and JavaScript redirects

A few years ago, for a project (which got cancelled) I experimented with opening a new tab when a user navigated to a new origin. I got stuck with redirects

So if understanding redirects well is very hard/fiddly, do you have any other idea how we could mitigate this scenario?

Turns out that the Clank team has already solved this problem for intents to external apps (Like opening the twitter app from Google search results). In order to mitigate this scenario you need the second part of InterceptNavigationDelegateImpl#onOverrideUrlLoadingAndLaunchIntent()

I will look into this soon.

I will not have time to look into this or to judge whether are any action items for us on this. Peter, sending to you to exercise your judgement.

Ok, I will take a look

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/384a1a848222a0b729321d06694a89d43e5551ab

commit 384a1a848222a0b729321d06694a89d43e5551ab
Author: Peter Kotwicz <pkotwicz@chromium.org>
Date: Sun Nov 26 22:14:15 2017

[Android WebAPK] Return to sensible page when closing CCT opened from TWA

This CL changes the behavior when a user taps a link from PAGE A to PAGE B where:
- PAGE B is in scope of the TWA
- the link redirects to PAGE C which is not in the scope of the TWA

This CL causes the TWA to navigate back to the last page that the user
interacted with (PAGE A). This way when the user closes the CCT
(which would have navigated to PAGE C), the user sees PAGE A instead
of PAGE B.

BUG= 741048 

Change-Id: I26e8725ab54629f215787fd830d756194e6c3955
Reviewed-on: https://chromium-review.googlesource.com/780901
Commit-Queue: Peter Kotwicz <pkotwicz@chromium.org>
Reviewed-by: Maria Khomenko <mariakhomenko@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519196}
[modify] https://crrev.com/384a1a848222a0b729321d06694a89d43e5551ab/chrome/android/java/src/org/chromium/chrome/browser/tab/InterceptNavigationDelegateImpl.java
[modify] https://crrev.com/384a1a848222a0b729321d06694a89d43e5551ab/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappInterceptNavigationDelegate.java
[modify] https://crrev.com/384a1a848222a0b729321d06694a89d43e5551ab/chrome/android/javatests/DEPS
[modify] https://crrev.com/384a1a848222a0b729321d06694a89d43e5551ab/chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebApkIntegrationTest.java
[modify] https://crrev.com/384a1a848222a0b729321d06694a89d43e5551ab/chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebappNavigationTest.java