Use Array.isArray in the LoopbackPort.

[yurydelendik]

For better serialization of Arrays that belong to different sandboxes.

See also http://logs.glob.uno/?c=mozilla%23pdfjs#c66373

/cc @tobytailor

[Rob--W]

Can we use Array.isArray everywhere?

For IE9, a polyfill can be added to compatibility.js.

[timvandermeij]

Indeed, wouldn't just changing https://github.com/mozilla/pdf.js/blob/master/src/shared/util.js#L1097 suffice so it's immediately used everywhere? For the polyfill we can use core-js since we already use it for clamped arrays (see be36c60).

[yurydelendik]

Can we use Array.isArray everywhere?

Maybe. There are too many places to check if they will work as expected when changed. For now I'm just addressing regression (and hope will not add another one :).

[yurydelendik]

For IE9, a polyfill can be added to compatibility.js.

Per MDN, Array.isArray is implemented in IE9

[Rob--W]

Even better. Then we don't need a polyfill at all.

[Snuffleupagus]

This seems fine, but it now needs a rebase :-)

r=me, with passing tests.

[Snuffleupagus]

/botio test

[pdfjsbot]

From: Bot.io (Linux m4)

---

Received

Command cmd_test from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.67.70.0:8877/2c396b7034ac963/output.txt

[pdfjsbot]

From: Bot.io (Windows)

---

Received

Command cmd_test from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.215.176.217:8877/4b9d5b098bdaf77/output.txt

[pdfjsbot]

From: Bot.io (Linux m4)

---

Success

Full output at http://54.67.70.0:8877/2c396b7034ac963/output.txt

Total script time: 16.47 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed

[pdfjsbot]

From: Bot.io (Windows)

---

Success

Full output at http://54.215.176.217:8877/4b9d5b098bdaf77/output.txt

Total script time: 29.25 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed