This is sort of tangential to coding, but programmers often do \"view source\" on their own pages and on others\' pages. I learned that when you do the normal View Source in
This is broken in Firefox for some time now:
https://bugzilla.mozilla.org/show_bug.cgi?id=307089
They aren't very responsive on their bug tracker, but your options are:
(1) complain at the bug tracker, (2) fix it yourself it's open source software, (3) find another browser.