1722305 - will-navigate doesn't fire and previous target isn't destroyed when navigating away from a bfcached *and* paused page

Status: RESOLVED FIXED

(DevTools :: Framework, defect)

Description

[Alexandre Poirot [:ochameau]]

When navigating away from a page that is paused and we are navigating to a page that was stored in the bfcache, we at least miss:

• DOCUMENT_EVENT's will-navigate.
  That's because ParentDocumentEventWatcher's onStateChange:
  https://searchfox.org/mozilla-central/rev/59e797b66f5ce8a27ede0e7677688931be7aed20/devtools/server/actors/resources/parent-process-document-event.js#76
  is not called when doing such navigation. Whereas it should be. When the page isn't paused it is correctly called. At first sight, it doesn't seem to be called at all.

• previous target of the page that is paused from which we navigate from is not reported as destroyed by the server.
  That's because DevToolsFrameChild.jsm's handleEvent:
  https://searchfox.org/mozilla-central/rev/59e797b66f5ce8a27ede0e7677688931be7aed20/devtools/server/connectors/js-window-actor/DevToolsFrameChild.jsm#525
  correctly receives a pagehide event, but its persisted attribute is false, whereas we would have expected it to be true. Because of that, we don't consider it as a bfcache navigation and do not destroy the target. And we don't notify the client about any destroyed target.

STR:

• Open a tab
• Load data:text/html,<script>debugger;</script>
• Navigate to data:text/html,foo
• Navigate back to data:text/html,<script>debugger;</script> (using back button)
• Open the debugger
• Reload the page
  => The debugger will pause on the debuggger statement
• Navigate to the second page (using forward button)
  => The debugger will still report to be paused on the previous page, while we loaded the second
  => The debugger should have been resumed. It isn't because we miss will-navigate. The miss of target-destroyed event isn't so important because we do get the notification of the new target of the second page. And the TargetCommand will report all previous target as being destroyed:
  https://searchfox.org/mozilla-central/rev/59e797b66f5ce8a27ede0e7677688931be7aed20/devtools/shared/commands/target/target-command.js#168-174

Comment 1

[Alexandre Poirot [:ochameau]]

Also see bug 1720443 comment 4

Comment 2

[Hubert Boma Manilla (:bomsy)]

Tested again and has been fixed!