Design bug in browse-url.el: browse-url-can-use-xdg-open's logic uses overly strict assumption

["Florian v. Savigny" <florian@fsavigny.de>]

Dear maintainers/authors,

browse-url-can-use-xdg-open returns t only if emacs is running under one of the desktop environments, i.e. Gnome, KDE, Xfce4 or LXDE.

I do not know the deeper reasons for this, but from experience, I can confirm that this running under a desktop environment may be sufficient, but is not necessary: My emacs is running under fvwm, and xdg-open works fine. (You have to know how to configure it, but that is no dark magic either; I do it via ~/.local/share/applications/mimeapps.list.)

My guess is that it would be sufficient to check for the existence of the xdg-open binary. The condition of one of the desktop environments being run is somewhat annoying, because when not fulfilled, it causes browse-url-default-browser, which is often employed to open a URL, to default to mozilla (or whatever follows in its hardcoded list), which may not be exactly what you want. Effectively, it makes it impossible to specify your favourite browser without some kludgy hack.

I have included some of the information produced by M-x report-emacs-bug, but since I am fairly certain that most of it is irrelevant, I have left it out:


In GNU Emacs 24.4.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.14.3)
 of 2014-10-21 on bitzer.hoetzel.info
Windowing system distributor `The X.Org Foundation', version 11.0.11601000
Configured using:
 `configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --with-x-toolkit=gtk3 --with-xft
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe
 -fstack-protector-strong --param=ssp-buffer-size=4'
 CPPFLAGS=-D_FORTIFY_SOURCE=2
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro'

Important settings:
  value of $LANG: de_DE.ISO-8859-1
  locale-coding-system: iso-latin-1-unix


Best regards,

Florian v. Savigny