solver3: Fix Recommends/Suggests vs Enhances confusion

We accidentally considered an Enhances a reason to keep
a package installed, which of course it is not, fix the
determination of "existing soft dependency" to only include
soft dependencies that should keep a package installed in
the autoremover to solve the issue.

This also fixes edsp/mantic-upgrade-rel-to-2024-05-29.edsp
to not install llvm-13-dev for clang-13 which is an installed
package with no upgrade.

Also ensure we stop after the first match; the DependsList()
is ordered by decreasing priority and we don't want to override
Recommends by Suggests in case a package declares both...

LP: #2101800

1 files changed, 9 insertions, 1 deletions

diff --git a/apt-pkg/solver3.cc b/apt-pkg/solver3.cc
index 739309c59..f992d55b4 100644
--- a/apt-pkg/solver3.cc
+++ b/apt-pkg/solver3.cc
@@ -833,9 +833,17 @@ APT::Solver::Clause APT::Solver::TranslateOrGroup(pkgCache::DepIterator start, p
       bool important = policy.IsImportantDep(start);
       bool newOptional = true;
       bool wasImportant = false;
+      auto importantToKeep = [this](pkgCache::DepIterator d)
+      {
+	 return policy.IsImportantDep(d) || (KeepRecommends && d->Type == pkgCache::Dep::Recommends) || (KeepSuggests && d->Type == pkgCache::Dep::Suggests);
+      };
+
       for (auto D = start.ParentPkg().CurrentVer().DependsList(); not D.end(); D++)
-	 if (not D.IsCritical() && not D.IsNegative() && D.TargetPkg() == start.TargetPkg())
+	 if (not D.IsCritical() && importantToKeep(D) && D.TargetPkg() == start.TargetPkg())
+	 {
 	    newOptional = false, wasImportant = policy.IsImportantDep(D);
+	    break;
+	 }
 
       bool satisfied = std::any_of(clause.solutions.begin(), clause.solutions.end(), [this](auto var)
 				   { return var.Pkg(cache) ? var.Pkg(cache)->CurrentVer != nullptr : Var(var.CastPkg(cache).CurrentVer()) == var; });