Bug#438999: Merge with #441178?

[Sven Joachim <svenjoac@gmx.de>]

I found this bug after wondering why this command retrieves the source
package from experimental:

$ apt-get source libdrm/unstable

but a slightly modified version works as intended, i.e. fetches the
version from unstable:

$ apt-get source libdrm2/unstable

The libdrm2 package is built from libdrm source, and there is no libdrm
binary package.  A nice explanation is found in
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=441178#50, where it is
also explained that another command,

$ apt-get source libdrm=2.4.18-5

will fetch the desired version.  Would it be correct to merge #438999
and #441178?

Sven