Steps to reproduce: 1. Make this file, hello.html: <script> console.log("hello world"); </script> 2. open it in nightly 3. open the debugger 4. set a breakpoint on the console.log call 5. reload Expected: breakpoint hits. Observed: the debugger pane visibly gets blanked as the page reloads; after that, the source code comes back but the breakpoint is gone.

sources don't appear in the Source View if the Debugger is opened after the page has finished loading.

Correction -- these steps do not reproduce the issue in a fresh tab; I have another test case which I'm minimizing now.

OK, try these STR: 1. create a file testcase.html containing the <script> tag below 2. start Firefox with a fresh profile 3. open the html file using a file: url 4. open the debugger (I use alt-cmd-S) 5. reload the page (I use cmd-r) 6. set breakpoint lines 4 and 5 (in that order) 7. reload the page <script> var a = function () { function b(ok) { console.log("4"); console.log("5"); throw new Error("6"); } b(false); }(); </script> expected: both breakpoints persist and hit observed: * either only one breakpoint persists, or both breakpoints persist as expected * but neither breakpoint hits (in either case) * output in the console shows that the console.log() lines both executed

Using the same STR but a different script, I was able to cause crashes: https://crash-stats.mozilla.com/report/index/cc16ba8b-6ca1-4e83-a316-238582130820 https://crash-stats.mozilla.com/report/index/8290e8c2-1dc7-4428-adfa-bcacd2130820 https://crash-stats.mozilla.com/report/index/058eccce-36ad-498b-9b1c-2baf62130820 but the crashes aren't reproducible. Here are some of the scripts I was using, in case it helps: <script> (function () { console.log("1"); if (document) { console.log("2"); throw "3"; } })(); </script> <script> (function () { function f() { console.log("1"); console.log("2"); throw "3"; } f(); })(); </script>

We just finished a refactor of the breakpoint code, which seems to have fixed this issue. Jason, can you confirm whether this is still an issue for you or not?

Jason, can you please respond to the ni?

I cannot reproduce this bug. I've asked Jason to confirm, but he has not replied to my ni? for over a month. Resolving this as fixed.