Backport popup related ASan crash fix to Tor Browser 6.x

It turns out that one of the crashes I found with ASan got already reported a couple of days earlier and fixed on trunk. The security rating indicates that Mozilla won't backport that patch to ESR 45. But we should do for safety's sake.

added GeorgKoppen201605 TorBrowserTeam201605R component::applications/tor browser owner::gk priority::high resolution::fixed severity::major status::closed tbb-crash type::task labels

Trac:
Summary: Backport popup related ASan crash to Tor Browser 6.x to Backport popup related ASan crash fix to Tor Browser 6.x

bug_19187 (https://gitweb.torproject.org/user/gk/tor-browser.git/commit/?h=bug_19187) is up for review. I've tested in a build that the crash is gone.

Trac:
Status: new to needs_review
Keywords: TorBrowserTeam201605 deleted, TorBrowserTeam201605R added

Arthur is fine with the backport. Taking as well for 6.0.1 as commit e38872520658a519cca3c69e635cd5cb6d825d21 on tor-browser-45.1.1esr-6.0-1

Trac:
Status: needs_review to closed
Resolution: N/A to fixed

closed

mentioned in issue #19400 (moved)

moved to tpo/applications/tor-browser#19187 (closed)