1352133 - Crash in java.lang.NullPointerException: Attempt to invoke virtual method ''java.lang.String org.mozilla.gecko.Tab.getMostRecentHomePanel()'' on a null object reference at org.mozilla.gecko.BrowserApp.hideBrowserSearch(BrowserApp.java)

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: General, defect, P1)

Description

[(inactive) Jim Chen [:jchen] [:darchons]]

This bug was filed from the Socorro interface and is 
report bp-fd3c7eb4-8384-4a76-9017-e77c42170329.
=============================================================

Looks like selected tab is null.

Comment 1

[Nevin Chen(Not active on Bugzilla)]

Since we are heavily working on tabs, we should look at this bug and fix it accordinately.

Comment 2

[Julien Cristau [:jcristau] (back April 22)]

What does P1 mean here?  It's been 3 months and this is still unassigned?

Comment 3

[Nevin Chen(Not active on Bugzilla)]

Attachment: Bug 1352133 - Check if selected tab is null when stop editing toolbar.

Review commit: https://reviewboard.mozilla.org/r/155660/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/155660/

Comment 4

[Nevin Chen(Not active on Bugzilla)]

Sorry I wasn't pay enough attension to this bug.

Comment 5

[Sebastian Kaspari (:sebastian; :pocmo)]

Comment on attachment 8884778 [details]
Bug 1352133 - Check if selected tab is null when stop editing toolbar.

https://reviewboard.mozilla.org/r/155660/#review163498

::: mobile/android/base/java/org/mozilla/gecko/BrowserApp.java:3128
(Diff revision 1)
> -
> +        final Tab selectedTab = Tabs.getInstance().getSelectedTab();
> +        if (selectedTab != null) {
> -        // To prevent overdraw, the HomePager is hidden when BrowserSearch is displayed:
> +            // To prevent overdraw, the HomePager is hidden when BrowserSearch is displayed:
> -        // reverse that.
> +            // reverse that.
> -        showHomePager(Tabs.getInstance().getSelectedTab().getMostRecentHomePanel(),
> -                Tabs.getInstance().getSelectedTab().getMostRecentHomePanelData());
> +            final String mostRecentHomePanel = selectedTab.getMostRecentHomePanel();
> +            showHomePager(mostRecentHomePanel,
> +                    selectedTab.getMostRecentHomePanelData());
> +        }

Have you been able to reproduce this? What happens if we do not show a panel here?

Comment 6

[Sebastian Kaspari (:sebastian; :pocmo)]

Comment on attachment 8884778 [details]
Bug 1352133 - Check if selected tab is null when stop editing toolbar.

https://reviewboard.mozilla.org/r/155660/#review166162

See questions in bug.

Comment 7

[Jan Henning [:JanH]]

With bug 1426613 fixed, the STR from 1426613 comment 8 now give me this crash.

Alternative STR (that I think don't depend on bug 1426613 being fixed) are: Follow steps 1. - 7. from the above bug, then in step 8:
Type something in the URL bar to show the BrowserSearch, then delete it again or press the "X" button to return back to the home panels.

I think the right solution is to fall back to the default home panel if we can't get it from the current tab (because the current tab doesn't actually exist early during startup).

Comment 8

[Jan Henning [:JanH]]

... that should be bug 1426613 comment 8.

Comment 9

[Jan Henning [:JanH]]

Attachment: Bug 1352133 - Handle selected tab not yet existing when exiting BrowserSearch.

Early during startup there might not be a selected tab yet, so we can't use its
data to decide which home panel to show again.

Fortunately showHomePager can be called with a null panelId, in which case it
will eventually simply fall back to using the default home panel from our
settings.

Review commit: https://reviewboard.mozilla.org/r/209456/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/209456/

Comment 10

[Nevin Chen(Not active on Bugzilla)]

Comment on attachment 8939019 [details]
Bug 1352133 - Handle selected tab not yet existing when exiting BrowserSearch.

https://reviewboard.mozilla.org/r/209456/#review215666

I can't reproduce but I think it's a working solution.

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/73863c493315
Handle selected tab not yet existing when exiting BrowserSearch. r=nechen

Comment 12

[Jan Henning [:JanH]]

Comment on attachment 8939019 [details]
Bug 1352133 - Handle selected tab not yet existing when exiting BrowserSearch.

[Feature/Bug causing the regression]: Awesomescreen
[User impact if declined]: Firefox could crash if the user interacts with the Awesomescreen before Firefox has opened any tabs.
[Is this code covered by automated tests?]: No.
[Has the fix been verified in Nightly?]: Tested locally.
[Needs manual test from QE? If yes, steps to reproduce]: No.
[List of other uplifts needed for the feature/fix]: Bug 1426864 and bug 1426613 are very similar crashes that might also happen along the same code path, i.e. if only one bug is fixed you might still crash because of one of the other bugs.
[Is the change risky?]: No.
[Why is the change risky/not risky?]: Just adding a null check before attempting to retrieve the last selected home panel - showHomePager itself can be safely called with a null panelId and will fall back to the default home panel in that case.
[String changes made/needed]: none

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/mozilla-central/rev/b5679bcdadf8
Handle selected tab not yet existing when exiting BrowserSearch. r=nechen

Comment 14

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/b5679bcdadf8

Comment 15

[Tiberius Oros[:tiberius_oros]]

https://hg.mozilla.org/mozilla-central/rev/73863c493315

Comment 16

[Gerry Chang [:gchang]]

Comment on attachment 8939019 [details]
Bug 1352133 - Handle selected tab not yet existing when exiting BrowserSearch.

Fix a crash related to Awesomescreen. Beta58+.

Comment 17

[Dorel Luca [:dluca]]

https://hg.mozilla.org/releases/mozilla-beta/rev/ac3cd70b8967