Closing a tab with middle mouse button click does not work.

E.g. open a PDF attachment with integrated viewer and try to close the PDF tab with middle mouse button click on the tab.

Thanks mozbugz! Indeed.

regressionwindow - Alice, would you?

Confirming 94.0a1 (2021-09-19) (64-bit), Win10. Middle-button click on tab does nothing.
Also broken on 93.0b2 (64-bit).
Still working on 91.1.1 (64-bit).

.

I also see this with 93.0b2 and 94.0a1 on Fedora 34 Workstation Linux. (64-bit)

Rehression windpw:
https://hg.mozilla.org/comm-central/pushloghtml?fromchange=000dd197a381fed989417cd45ae7d25cfd3be53c&tochange=99166a3245724c3188ebd041d0b13c3b691fdfac
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=6c984a259bdc8d11cb4fe887b9ae2c6add2545e5&tochange=e84a121c42cbc3d6882ccd7c2341aa31eecdc05f

Still broken in 93.0b4. The error in the console:

 Uncaught TypeError: document.tab is undefined
    onTabClick chrome://messenger/content/tabmail.js:1724
    onclick chrome://messenger/content/messenger.xhtml:1

In the code:

    onTabClick(event) {
      // a middle mouse button click on a tab is a short cut for closing a tab
      if (event.button != 1 || document.tab.localName != "tab") {

Also, why are you not using !==? Even without a linter my IDE would still complain about not strict equality! And seeing let everywhere :(...
Please excuse my negative comments, it's a professional deformation finding issues in other people code :)

Definition of document.tab was removed by patch( https://hg.mozilla.org/comm-central/rev/c6695c5b570849c35824313a34abe6dc6f44160c#l4.62 ) of Bug 1683865.

Restored:

• Middle mouse click on a tab closes it.
• Prevent switching to a tab before closing it when the tab's close button is clicked.

Try run for the new test https://treeherder.mozilla.org/jobs?repo=try-comm-central&revision=1f0cb9926c6d7ec8cd5011e0753c412c309bb1e2

With fix for macosx https://treeherder.mozilla.org/jobs?repo=try-comm-central&revision=eb97f79e7069ee07fceebd6b8b803669343d1ea2

Pushed by geoff@darktrojan.net:
https://hg.mozilla.org/comm-central/rev/a5a2b7acbee1
Fix closing tabs issues introduced by rev c6695c5b5708. r=mkmelin