Overriding shlibs dep for some packages with higher versions

[Loïc Minier <lool+debian@via.ecp.fr>]

        Hi,

 I'm in a situation where I'd like to bump dependencies in binary
 packages of a source package to >= upstream version when they
 interdepend on each other.  This is somewhat similar to adding a (=
 ${Source-Version}) constraint in spirit and in the implementation.

 The problem is that some dependencies are already pulled in via
 ${shlibs:depends}: I don't want dependencies to appear twice.

 I've turned around the man pages of dh_gencontrol/dpkg-gencontrol, and
 of dh_shlibdeps/dpkg-shlibdeps, and while it seems possible to override
 a shlib dependency, it doesn't seem to be possible to take the
 "highest of the two".

 In summary, what I want is something like:
 debian/control: Depends: ${shlibs-depends}, libfoo (>= x.y)
 debian/substvars: shlibs-depends: libfoo (>= x.0)

 => DEBIAN/control: Depends: libfoo (>= x.y)

 Although I didn't find any lintian warning on double depends, I presume
 they're not particularly welcome.

 Side note: this would be particularly useful if I forget to bump the >=
 x.y dependency (which is generated anyway).

 If this can't be done easily, I'll resort to double-depends.

   Bye,

PS: in case you wonder why the shlibs aren't bumped, this is because
upstream guarantees its interfaces, but might use some non-declared
functions internally, ie. functions that are not in API headers, and
expects binary packages not to mix upstream versions.
-- 
Loïc Minier <lool@dooz.org>
"Neutral President: I have no strong feelings one way or the other."