1405096 - TypeError: webconsolePanel is null

Status: NEW

(DevTools :: Console, defect, P3)

Description

[Oriol Brufau [:Oriol]]

1. Create this PHP script in a local server:

    <?php
    header('Content-type: application/json');
    set_time_limit(0);
    $i = 0;
    echo "[\n";
    while(true) {
      ++$i;
      echo "    ", $i, ",\n";
      ob_end_flush();
      flush();
      ob_start();
      sleep(1);
    }
    ?>

2. Load it.
3. Open web console (Ctrl+Shift+K)
4. Switch to Inspector panel.
5. Close Developer Tools (it won't fully close until the page loads completely, which is not going to happen).
6. Open web console (Ctrl+Shift+K)

Result: Web console does not load and browser console shows this error:

A promise chain failed to handle a rejection. Did you forget to '.catch', or did you forget to 'return'?
See https://developer.mozilla.org/Mozilla/JavaScript_code_modules/Promise.jsm/Promise

Date: Mon Oct 02 2017 21:25:54 GMT+0200 (Romance Standard Time)
Full Message: TypeError: webconsolePanel is null
Full Stack: _refreshConsoleDisplay@resource://devtools/shared/base-loader.js -> resource://devtools/client/framework/toolbox.js:936:7
selectTool@resource://devtools/shared/base-loader.js -> resource://devtools/client/framework/toolbox.js:1806:5
DevTools.prototype.showToolbox<@resource://devtools/shared/base-loader.js -> resource://devtools/client/framework/devtools.js:456:15
_run@resource://devtools/shared/base-loader.js -> resource://devtools/shared/task.js:310:39
TaskImpl@resource://devtools/shared/base-loader.js -> resource://devtools/shared/task.js:272:3
asyncFunction@resource://devtools/shared/base-loader.js -> resource://devtools/shared/task.js:246:14
selectToolCommand@resource://devtools/shared/base-loader.js -> resource://devtools/client/framework/devtools-browser.js:237:7
onKeyShortcut@resource://devtools/shared/base-loader.js -> resource://devtools/client/framework/devtools-browser.js:260:7
onKey@jar:file:///C:/Program%20Files/Mozilla%20Firefox/Nightly/browser/omni.ja!/components/devtools-startup.js:364:5
hookKeyShortcuts/xulKey<@jar:file:///C:/Program%20Files/Mozilla%20Firefox/Nightly/browser/omni.ja!/components/devtools-startup.js:350:51
EventListener.handleEvent*createKey@jar:file:///C:/Program%20Files/Mozilla%20Firefox/Nightly/browser/omni.ja!/components/devtools-startup.js:384:5
hookKeyShortcuts@jar:file:///C:/Program%20Files/Mozilla%20Firefox/Nightly/browser/omni.ja!/components/devtools-startup.js:350:20
hookWindow@jar:file:///C:/Program%20Files/Mozilla%20Firefox/Nightly/browser/omni.ja!/components/devtools-startup.js:239:5
onWindowReady@jar:file:///C:/Program%20Files/Mozilla%20Firefox/Nightly/browser/omni.ja!/components/devtools-startup.js:212:7
_delayedStartup@chrome://browser/content/browser.js:1597:5
EventListener.handleEvent*onLoad@chrome://browser/content/browser.js:1396:5
onload@chrome://browser/content/browser.xul:1:1

Comment 1

[Brian Grinstead [:bgrins]]

I wonder if the toolbox, inspector, or console is waiting for an event that never fires in this case. A hosted web page to triggers the issue would be very helpful for debugging.

Comment 2

[Oriol Brufau [:Oriol]]

OK, steps without PHP:

1. Load about:blank
2. Open the web console (Ctrl+Shift+K)
3. Enter this code:
   document.open();
4. Switch to Inspector panel.
5. Close Developer Tools (it won't fully close).
6. Open web console (Ctrl+Shift+K)

Comment 3

[Oriol Brufau [:Oriol]]

Issue in comment 2 was fixed by bug 1414597.
But I can still reproduce the issue in comment 0.
Brad, do you want to investigate this too?

Comment 4

[Brad Werth [:bradwerth]]

I can't reproduce this with the same outcome as comment 0, but I can get the inspector to fail to close and fail to re-open. The only message I get in the Browser Console (when attempting to re-open the Web Console) is:

TelemetryStopwatch: requesting elapsed time for nonexisting stopwatch. Histogram: "DEVTOOLS_INSPECTOR_TIME_ACTIVE_SECONDS", key: "null" TelemetryStopwatch.jsm:388 

I'll see if I can figure out what to do to make the tools close and re-open properly.