Created attachment 517852 [details] output of emerge --info I'm using current xfce4-4.12 with thunar, and greybird as my main theme for it. If building firefox-esr or thunderbird with gtk3 support instead of gtk2, it gives me much bolder seperation lines in the context menu. This shouldn't be the case, I will attach some screenshots to show my point.
Created attachment 517854 [details] screenshot of contextmenu from thunderbird These seperation lines should be present, but much more subtle. Also the background of the email I opened in the bottom half should not have gray as background but white.
Created attachment 517856 [details] screenshot from an old ubuntu vm with firefox-54 installed Suspected x11-themes/gtk-engines-xfce:0 , and installed x11-themes/gtk-engines-xfce:3 instead. Also I flipped around the themes, tried Adwaita instead, to no success. My icon theme is Faenza, if that matters. The same happens when using the firefox-bin version, or thunderbird-bin. I attached a screenshot from an older ubuntu vm with firefox-54 installed, which has obviously gtk3 enabled, and which doesn't show these thick seperation lines and neither a grey background but a white one. My workaround for this was to stick with firefox-esr and gtk2 for as long as possible, but there will be a new esr without gtk2 support soon. How can I find out more about this, which package has to be blamed - gtk-engines, firefox | thunderbird, greybird?
Firefox and thunderbird aren't really gtk applications, they mostly just use it to try to render the same theme or something. Re-assigning to mozilla@.
So this just so happens to be my environment (xfce-4.12, greybird theme) and although I do see what you're seeing with 52.6 (and don't in 58.0.1) I'm not sure if this is something that's likely to be fixed in the ESRs. I'l look into it but messing about with patches to the theme code wasn't much fun last time I tried, and I doubt i'm going to be able to find a nice clean upstream commit to backport.
Created attachment 518256 [details] super simpel html test page Talking about those too bold lines, if they are fixed for recent firefox that is absolutly fine by me, I don't expect the fix to be backported to esr. Also I just tested with firefox-bin-58.0.1 and can confirm, that the context menu was fixed. However, it does still show a grey background where there should be just plain white, and this mostly with webpages which are really simple and non sophisticated. I attached a "testcase" for this, the html file is tiny even. Behavior with firefox-esr +gtk2 is white background, behavior with firefox-esr -gtk2 (and firefox-58.x) is a grey background. Is this the same for you? firefox useflags, non affected version ebuild R ] www-client/firefox-52.6.0::gentoo USE="custom-cflags custom-optimization dbus eme-free gtk2 hwaccel system-harfbuzz system-icu system-jpeg system-libevent system-libvpx system-sqlite -bindist -debug -gmp-autoupdate -hardened -jack -jemalloc (-neon) -pgo -pulseaudio (-rust) (-selinux) -startup-notification (-system-cairo) {-test} -wifi" L10N="de -ach -af -an -ar -as -ast -az -bg -bn-BD -bn-IN -br -bs -ca -cak -cs -cy -da -dsb -el -en-GB -en-ZA -eo -es-AR -es-CL -es-ES -es-MX -et -eu -fa -ff -fi -fr -fy -ga -gd -gl -gn -gu -he -hi -hr -hsb -hu -hy -id -is -it -ja -ka -kab -kk -km -kn -ko -lij -lt -lv -mai -mk -ml -mr -ms -nb -nl -nn -or -pa -pl -pt-BR -pt-PT -rm -ro -ru -si -sk -sl -son -sq -sr -sv -ta -te -th -tr -uk -uz -vi -xh -zh-CN -zh-TW" 0 KiB
(In reply to tt_1 from comment #5) > Created attachment 518256 [details] > super simpel html test page > > Talking about those too bold lines, if they are fixed for recent firefox > that is absolutly fine by me, I don't expect the fix to be backported to > esr. Also I just tested with firefox-bin-58.0.1 and can confirm, that the > context menu was fixed. > > However, it does still show a grey background where there should be just > plain white, and this mostly with webpages which are really simple and non > sophisticated. > The grey background is, believe it or not, firefox doing its job in honouring the gryebird theme. If you want to address that you need to specify an override defaunt background by turning off Preferences -> Colors (under "Fonts and Colors") -> Use system colors and selecting the background you want. OK I'll switch this to RESO/UPSTREAM since it will eventually come down the pipe with the next ESR.
