Bug#687643: apt-cudf specifies a version number for install requests even when not needed

[Pietro Abate <pietro.abate@pps.jussieu.fr>]

Package: apt-cudf
Version: 3.0.2-1
Severity: normal

Dear Maintainer,
   the code that translates EDSP into CUDF in apt-cudf always adds a version
   number to the packages on the request line; this behaviour is
   incorrect, as it prevents the search for relaxed installation
   solutions when apt-cudf-get is used in conjunction with it.

   A patch is attached.

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

Kernel: Linux 3.5-trunk-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

Versions of packages apt-cudf depends on:
ii  aspcud [cudf-solver]  2011.03.17.dfsg-6
ii  libbz2-1.0            1.0.6-4
ii  libc6                 2.13-35
ii  libpcre3              1:8.31-1
ii  mccs [cudf-solver]    1:1.1-2
ii  packup [cudf-solver]  0.6-1
ii  perl                  5.14.2-13
ii  zlib1g                1:1.2.7.dfsg-13

apt-cudf recommends no packages.

apt-cudf suggests no packages.

-- no debconf information

diff --git a/applications/apt-cudf.ml b/applications/apt-cudf.ml
index ffbb872..5ae7fdc 100644
--- a/applications/apt-cudf.ml
+++ b/applications/apt-cudf.ml
@@ -63,27 +63,37 @@ let print_progress ?i msg =
     Format.printf "Message: %s@." msg
 ;;
 
+
+(* Debian specific assumption: only one version of a package 
+   can be installed at a given time.
+   Hence, when a remove request is issued without version constraint,
+   we return (candidate.Cudf.package,None) that designates the only
+   package installed.
+ *)
+
 let make_request tables universe native_arch request = 
   let to_cudf (p,v) = (p,Debian.Debcudf.get_cudf_version tables (p,v)) in
+  let get_candidate (name,constr) = 
+    try
+      List.find 
+	(fun pkg -> 
+	  try (Cudf.lookup_package_property pkg "apt-candidate") = "true"
+	  with Not_found -> false) 
+	(CudfAdd.who_provides universe (name,constr))
+    with Not_found -> 
+      print_error "Package %s does not have a suitable candidate" name
+  in
   let select_packages ?(remove=false) l = 
     List.map (fun ((n,a),c) -> 
       let (name,constr) = Boilerplate.debvpkg ~native_arch to_cudf ((n,a),c) in
-      let candidate = 
-        try
-          List.find (fun pkg ->
-            if request.Edsp.strict_pin then
-              try (Cudf.lookup_package_property pkg "apt-candidate") = "true"
-              with Not_found -> false
-            else
-              true
-          ) (CudfAdd.who_provides universe (name,constr))
-        with Not_found -> 
-          print_error "Package %s does not have a suitable candidate" n
-      in
       if remove then
-        (candidate.Cudf.package,None)
+        (name,None)
       else
-        (candidate.Cudf.package,Some(`Eq,candidate.Cudf.version))
+	match constr, request.Edsp.strict_pin with
+          None, false -> (name, None)
+	| _, _ -> (name,Some(`Eq,(get_candidate (name,constr)).Cudf.version))
+        (* FIXME: when apt will accept version constraints different from `Eq,
+           we will need to pass them through. *)
     ) l 
   in
   if request.Edsp.upgrade || request.Edsp.distupgrade then