Inkscape fails to find executable dependencies of extensions if there is a empty $PATH entry

[Bolche]

OS: Ubuntu 12.04 LTS (64 bits)
In Inkscape 0.48.3.1, if the PATH variable has an empty entry, for example, /usr/lib/lightdm/lightdm::/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games (note the ":" appears twice after lightdm), Inkscape fails to find executable dependencies of extensions and so it fails to load extensions such as "LaTeX formula" even though all it's dependencies (latex, pstoedit, etc...) are installed.

Strace (PATH=:$PATH strace inkscape) shows that, apparently, the PATH components aren't correctly parsed:
access(":/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games/latex", F_OK) = -1 ENOENT (No such file or directory)

if the PATH variable was correctly parsed, the result would be:
access("/usr/lib/lightdm/lightdm/latex", F_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/lightdm/lightdm/latex", X_OK) = -1 ENOENT (No such file or directory)
access("/usr/lib/lightdm/lightdm/latex.exe", F_OK) = -1 ENOENT (No such file or directory)
...
access("/usr/sbin/latex.cmd", F_OK) = -1 ENOENT (No such file or directory)
access("/usr/sbin/latex.cmd", X_OK) = -1 ENOENT (No such file or directory)
access("/usr/bin/latex", F_OK) = 0

This bug can be reproduce by running, for example, PATH=:$PATH inkscape

While empty entries in PATH can be a little weird, it happened to me thanks to a bash script that exported PATH without checking if some entry was empty. It didn't cause trouble with any other program.

[su_v (suv-lp)]

Duplicate of bug #801568 “Incorrect PATH scan results in extensions not found”?
<https://bugs.launchpad.net/inkscape/+bug/801568>

[su_v (suv-lp)]

Linking as duplicate to bug #801568 - please add a comment here and revert the duplicate status if you don't agree and think these are different issues.