solver3: Allow any downloadable version to mark a package as not obsolete

Lots of people have pinned an older version that is no longer
installable, or more common yesterday, we saw a lot of people
who seemingly manually installed a newer version of a deb than
in the repositories, causing the package to be considered obsolete,
which does not make much sense.

Oops: 4c39d922-410f-11f0-bbf9-fa163ec44ecd
Oops: a64054f6-4140-11f0-bbfd-fa163ec44ecd
Oops: a32196c1-661d-11f0-a97c-fa163ec8ca8c

2 files changed, 21 insertions, 6 deletions

diff --git a/apt-pkg/solver3.cc b/apt-pkg/solver3.cc
index 2c381f098..a386b967c 100644
--- a/apt-pkg/solver3.cc
+++ b/apt-pkg/solver3.cc
@@ -542,11 +542,16 @@ bool APT::Solver::Obsolete(pkgCache::PkgIterator pkg, bool AllowManual) const
    if (ObsoletedByNewerSourceVersion(ver))
       return true;
 
-   if (ver.Downloadable())
+   // Any version downloadable is good enough for us tbh
+   for (auto ver = pkg.VersionList(); not ver.end(); ++ver)
    {
-      pkgObsolete[pkg] = 1;
-      return false;
+      if (ver.Downloadable())
+      {
+	 pkgObsolete[pkg] = 1;
+	 return false;
+      }
    }
+
    if (debug >= 3)
       std::cerr << "Obsolete: " << ver.ParentPkg().FullName() << "=" << ver.VerStr() << " - not installable\n";
    pkgObsolete[pkg] = 2;
diff --git a/test/integration/test-solver3-obsoleted-by b/test/integration/test-solver3-obsoleted-by
index dda6b61f0..308e05481 100755
--- a/test/integration/test-solver3-obsoleted-by
+++ b/test/integration/test-solver3-obsoleted-by
@@ -8,12 +8,20 @@ configarchitecture 'amd64'
 allowremovemanual
 
 # We need a canary to make it trigger obsolete detection
-insertpackage 'installed' 'canary' 'amd64' '1' 'Depends: good | not-yet-built | not-yet-built-all | obsolete | obsolete-all | obsolete-in-experimental | obsolete-reason | obsolete-all-reason | obsolete-in-experimental-reason | local-only | current-version | obsolete-in-downgrade | obsolete-in-downgrade-reason'
+insertpackage 'installed' 'canary' 'amd64' '1' 'Depends: good | good-in-new-version | good-in-old-version | not-yet-built | not-yet-built-all | obsolete | obsolete-all | obsolete-in-experimental | obsolete-reason | obsolete-all-reason | obsolete-in-experimental-reason | local-only | current-version | obsolete-in-downgrade | obsolete-in-downgrade-reason'
 
 # This package is good, it still exists in the candidate
 insertpackage 'installed' 'good' 'amd64' '1' 'Source: good (= 1)'
 insertpackage 'unstable' 'good' 'amd64' '2' 'Source: good (= 2)'
 
+# This package is good, it still exists in the candidate
+insertpackage 'installed' 'good-in-old-version' 'amd64' '2' 'Source: good-in-old-version (= 2)'
+insertpackage 'unstable' 'good-in-old-version' 'amd64' '1' 'Source: good-in-old-version (= 1)'
+
+# This package is good, it still exists in the candidate
+insertpackage 'installed' 'good-in-new-version' 'amd64' '1' 'Source: good-in-new-version (= 1)'
+insertpackage 'unstable' 'good-in-new-version' 'amd64' '2' 'Source: good-in-new-version (= 2)'
+
 # not-yet-built is not yet obsolete, because it has only been built on i386
 insertpackage 'installed,unstable' 'not-yet-built' 'amd64' '1' 'Source: not-yet-built (= 1)'
 insertpackage 'unstable' 'not-yet-built' 'i386' '2' 'Source: not-yet-built (= 2)'
@@ -79,15 +87,17 @@ Obsolete: local-only:amd64=1 - not installable" aptget dist-upgrade --no-strict-
 
 msgmsg "Testing no-strict-pinning with negative pins on all packages"
 printf 'Package: *\nPin: release *\nPin-Priority: -1\n' > rootdir/etc/apt/preferences
-testobsolete "Obsolete: not-yet-built:amd64 - not installable
+testobsolete "Obsolete: good-in-new-version:amd64 - not installable
 Obsolete: good:amd64 - not installable
+Obsolete: good-in-old-version:amd64 - not installable
+Obsolete: not-yet-built:amd64 - not installable
 Obsolete: not-yet-built-all:amd64 - not installable
 Obsolete: obsolete:amd64 - not installable
 Obsolete: obsolete-all:amd64 - not installable
 Obsolete: obsolete-in-experimental:amd64 - not installable
+Obsolete: obsolete-all-reason:amd64 - not installable
 Obsolete: obsolete-reason:amd64 - not installable
 Obsolete: obsolete-in-experimental-reason:amd64 - not installable
-Obsolete: obsolete-all-reason:amd64 - not installable
 Obsolete: local-only:amd64 - not installable
 Obsolete: current-version:amd64 - not installable
 Obsolete: obsolete-in-downgrade:amd64 - not installable