Xdg-open reads the entire file while determining the program to open it
with. This may take a long time if the file is large or on a slow medium.

I use fluxbox and therefore xdg-open uses open_generic_xdg_mime(). The for
loop (L539) is run 3 times and first two iterations do not match either of
the following if clauses. Therefore the original filename ($file) is
passed as an argument to the following greps (L549,L551) and the file is
grepped through several times.

As a quick fix I added an else clause clearing the $file in case the if's
do not match. A more proper fix might be to verify that $file is actually
*.desktop in the latter if clause (L348), but I'll leave that to the pros
:)

for x in `echo "$xdg_user_dir:$xdg_system_dirs" | sed 's/:/ /g'`; do
   local file
   # look for both vendor-app.desktop, vendor/app.desktop
   if [ -r "$x/applications/$default" ]; then
     file="$x/applications/$default"
   elif [ -r "$x/applications/`echo $default | sed -e 's|-|/|'`" ]; then
     file="$x/applications/`echo $default | sed -e 's|-|/|'`"
+ else
+   file=""
   fi

Dear maintainer,

xdg-open is broken, and using it for big files effectively makes xdg-open
unusable for generic case (ie. no DE).

There is also **security issue** since xdg-open could be manipulated to run any
executable if `grep -E "^Exec(\[[^]=]*])?=` match on given file. This is
potentionaly very dangerous.

Since the bug is generally name collision I suggest renaming the affected
variable as quick bugfix.

Cheers,
Jiri

System Information:
Debian Release: jessie/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'testing-updates'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

xdg-utils depends on no packages.

Versions of packages xdg-utils recommends:
pn  libfile-mimeinfo-perl  <none>
pn  libnet-dbus-perl       <none>
pn  libx11-protocol-perl   <none>
ii  x11-utils              7.7+2
ii  x11-xserver-utils      7.7+3+b1

Versions of packages xdg-utils suggests:
pn  gvfs-bin  <none>