Steps To Reproduce: 1. Open e10s windw 2. Open about:newtab 3. Open Developer Tools such as Network (Ctrl+Shift+Q) 4. Open any web page Actual Results: Developer Tools is closing. I cannot verify network activities in this case. Expected Results: Developer Tools should be staying open.
Regression window(fx) Good(the dev tool is staying, though it does not function): https://hg.mozilla.org/integration/fx-team/rev/6f233e72cb49 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0 ID:20140826182328 Bad: https://hg.mozilla.org/integration/fx-team/rev/f14b2654c180 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0 ID:20140827032228 Pushlog: https://hg.mozilla.org/integration/fx-team/pushloghtml?fromchange=6f233e72cb49&tochange=f14b2654c180
I investigated this a bit while ago and I discovered that the toolbox closes because the docshell it has attached is destroyed. Apparently some (all?) about:* pages are rendered in the parent process. When a web page is opened a new docshell is created in a child process. This takes over the tab and the original docshell in parent process is destroyed which causes the developer tools to close if they were attached to the original docshell.
This looks like a dupe of bug 1068400