Show a separate list of upgrades deferred due to phasing

This introduces a new line:

    The following upgrades have been deferred due to phasing

This is any kept back package that is also phasing. This may
not be 100% accurate as we have kept it back due to other reasons
in an install command, for example, but we don't track for which
packages we applied phasing in reality.

If additional packages are kept back that are not phasing, show
a a notice

"N: Some packages may have been kept back due to phasing."

LP: #1988819

3 files changed, 27 insertions, 1 deletions

diff --git a/apt-private/private-install.cc b/apt-private/private-install.cc
index 2f254ca27..dbcba8fd1 100644
--- a/apt-private/private-install.cc
+++ b/apt-private/private-install.cc
@@ -210,11 +210,26 @@ bool InstallPackages(CacheFile &Cache, APT::PackageVector &HeldBackPackages, boo
 	 return false;
    }
 
+   APT::PackageVector PhasingPackages;
+   APT::PackageVector NotPhasingHeldBackPackages;
+   for (auto const &Pkg : HeldBackPackages)
+   {
+      if (Cache->PhasingApplied(Pkg))
+	 PhasingPackages.push_back(Pkg);
+      else
+	 NotPhasingHeldBackPackages.push_back(Pkg);
+   }
+
    // Show all the various warning indicators
    ShowDel(c1out,Cache);
    ShowNew(c1out,Cache);
    if (ShwKept == true)
-      ShowKept(c1out,Cache, HeldBackPackages);
+   {
+      ShowPhasing(c1out, Cache, PhasingPackages);
+      ShowKept(c1out, Cache, NotPhasingHeldBackPackages);
+      if (not PhasingPackages.empty() && not NotPhasingHeldBackPackages.empty())
+	 _error->Notice("Some packages may have been kept back due to phasing.");
+   }
    bool const Hold = not ShowHold(c1out,Cache);
    if (_config->FindB("APT::Get::Show-Upgraded",true) == true)
       ShowUpgraded(c1out,Cache);
diff --git a/apt-private/private-output.cc b/apt-private/private-output.cc
index 03fbe47e1..c73d5229b 100644
--- a/apt-private/private-output.cc
+++ b/apt-private/private-output.cc
@@ -490,6 +490,16 @@ void ShowDel(ostream &out,CacheFile &Cache)
 	 CandidateVersion(&Cache));
 }
 									/*}}}*/
+// ShowPhasing - Show packages kept due to phasing			/*{{{*/
+void ShowPhasing(ostream &out, CacheFile &Cache, APT::PackageVector const &HeldBackPackages)
+{
+   SortedPackageUniverse Universe(Cache);
+   ShowList(out, _("The following upgrades have been deferred due to phasing:"), HeldBackPackages,
+	    &AlwaysTrue,
+	    &PrettyFullName,
+	    CurrentToCandidateVersion(&Cache));
+}
+									/*}}}*/
 // ShowKept - Show kept packages					/*{{{*/
 void ShowKept(ostream &out,CacheFile &Cache, APT::PackageVector const &HeldBackPackages)
 {
diff --git a/apt-private/private-output.h b/apt-private/private-output.h
index d6f25e1ec..c3e73d592 100644
--- a/apt-private/private-output.h
+++ b/apt-private/private-output.h
@@ -93,6 +93,7 @@ template<class Container, class PredicateC, class DisplayP, class DisplayV> bool
 void ShowNew(std::ostream &out,CacheFile &Cache);
 void ShowDel(std::ostream &out,CacheFile &Cache);
 void ShowKept(std::ostream &out,CacheFile &Cache, APT::PackageVector const &HeldBackPackages);
+void ShowPhasing(std::ostream &out, CacheFile &Cache, APT::PackageVector const &HeldBackPackages);
 void ShowUpgraded(std::ostream &out,CacheFile &Cache);
 bool ShowDowngraded(std::ostream &out,CacheFile &Cache);
 bool ShowHold(std::ostream &out,CacheFile &Cache);