Regression: GUI screen resolution seems wrong #17153
Description
Affects 0.18.1 and 0.19.0rc1.
Before 099e4b9 from PR #16254 (backported to 0.18.1 in #16035), icons and text in the GUI seem to correspond to each other nicely. With that commit applied, the text size on the main window hasn't changed but the icons seem huge and the window size is double its normal size. On dialogs, the text seems like it might even be smaller than before and the dialogs don't entirely fit on my laptop screen.
Running export QT_AUTO_SCREEN_SCALE_FACTOR=0 before starting bitcoin-qt (0.19.0rc1 binaries from BitcoinCore.org) fixes the problem. (Documentation for this option)
Example images provided at the bottom of this post. Assorted information about my system below. Note: I tested 0.19.0rc1 on my host operating system; builds of 099e4b9 and 099e4b9^ were run using ssh -X into an lxc container running the same version of Debian (I don't think this should cause any differences, but it could).
$ uname -a
Linux ganymede 4.19.0-5-amd64 #1 SMP Debian 4.19.37-5 (2019-06-19) x86_64 GNU/Linux
$ cat /etc/issue
Debian GNU/Linux 10 \n \l
$ xrandr | head -n1
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
$ dpkg -l '*qt*core*'
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==========================-================-============-========================================
ii libqt5core5a:amd64 5.11.3+dfsg1-1 amd64 Qt 5 core module
ii libqt5webenginecore5:amd64 5.11.3+dfsg-2+b1 amd64 Web content engine library for Qt - Core
ii libqtcore4:amd64 4:4.8.7+dfsg-18 amd64 Qt 4 core module
un lxqt-core <none> <none> (no description available)
ii qtcore4-l10n 4:4.8.7+dfsg-18 all Qt 4 core module translations
$ xdpyinfo | head -n5
name of display: :0
version number: 11.0
vendor string: The X.Org Foundation
vendor release number: 12004000
X.Org version: 1.20.4
Expected images taken from parent of 099e4b9
Unexpected images taken from 099e4b9 and matching 0.19.0rc1