Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:59.0) Gecko/20100101 Firefox/59.0 Build ID: 20171215220126 Steps to reproduce: - open the devtools (F12) - switch to the inspector tool - resize the sidebar on the right (containing the rules view) - close the devtools (F12) - open the devtools again (F12) Actual results: the width of the sidebar was reset to its default Expected results: the resize width of the sidebar should have been retained This is a usability regression.

Regression range: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=8af527a897919ee29c1a94efa50d2cf6ddf839fd&tochange=0313f74cb8ff78ade014e5f6a4bb082be374b012 0313f74cb8ff Gabriel Luong — Bug 1369945 - Display a split rule view panel in the inspector. r=bgrins

Hey Gabe. Do you mind taking a quick look at this one please? This is a regression that we need to fix in the 59 timeframe.

Pushed by gabriel.luong@gmail.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/fc42dcda29cf Inspector should retain the width of its sidebar on reopen. r=mparkms

Confirmed fixed with Nightly build 20171222100407. Thanks.

I have successfully reproduced the bug in firefox Nightly 59.0a1 (2017-12-16) with windows 10 (32 bit) Verified as fixed with latest nightly 59.0a1 (2018-01-06) (32-bit) Build ID: 20180106220101 Mozilla/5.0 (Windows NT 10.0; rv:59.0) Gecko/20100101 Firefox/59.0

I have successfully reproduced the bug with Nightly 59.0a1 (2017-12-16) on Ubuntu 12.04 LTS! This bug's fix is Verified with latest Beta! Build ID : 20180209162511 User Agent : Mozilla/5.0 (X11; Linux x86_64; rv:59.0) Gecko/20100101 Firefox/59.0 [bugday-20180228]

I have successfully reproduced the bug with Nightly 59.0a1 (2017-12-15) on Windows 10(x64). The bug's fix is verified on Firefox 59.0b14 , 60.0a1 (2018-03-05) and Dev Edition 60.0b1(20180302190033) on Ubuntu 16.04(x64), Windows 10(x64) and macOS 10.12.6.