Protect a package while resolving in MarkInstall

Strange things happen if while resolving the dependencies of a package
said dependencies want to remove the package. The allow-scores test e.g.
removed the preferred alternative in favor of the last one now that they
were exclusive. In our or-group for Recommends we would "just" not
statisfy the Recommends and for Depends we engage the ProblemResolver…

4 files changed, 48 insertions, 39 deletions

diff --git a/apt-pkg/depcache.cc b/apt-pkg/depcache.cc
index 2254a9b5d..7730aaf5b 100644
--- a/apt-pkg/depcache.cc
+++ b/apt-pkg/depcache.cc
@@ -1180,7 +1180,7 @@ bool pkgDepCache::MarkInstall_RemoveConflictsIfNotUpgradeable(pkgCache::VerItera
    return true;
 }
 									/*}}}*/
-bool pkgDepCache::MarkInstall_UpgradeOrRemoveConflicts(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, APT::PackageVector &toUpgrade) /*{{{*/
+bool pkgDepCache::MarkInstall_UpgradeOrRemoveConflicts(bool const propagateProctected, unsigned long Depth, bool const ForceImportantDeps, APT::PackageVector &toUpgrade) /*{{{*/
 {
    for (auto const &InstPkg : toUpgrade)
       if (not MarkInstall(InstPkg, true, Depth + 1, false, ForceImportantDeps))
@@ -1189,14 +1189,14 @@ bool pkgDepCache::MarkInstall_UpgradeOrRemoveConflicts(PkgIterator const &Pkg, u
 	    std::clog << OutputInDepth(Depth) << " Removing: " << InstPkg.FullName() << " as upgrade is not possible\n";
 	 if (not MarkDelete(InstPkg, false, Depth + 1, false))
 	    return false;
-	 if (PkgState[Pkg->ID].Protect())
+	 if (propagateProctected)
 	    MarkProtected(InstPkg);
       }
    toUpgrade.clear();
    return true;
 }
 									/*}}}*/
-bool pkgDepCache::MarkInstall_InstallDependencies(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, std::vector<pkgCache::DepIterator> &toInstall, APT::PackageVector *const toMoveAuto) /*{{{*/
+bool pkgDepCache::MarkInstall_InstallDependencies(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, std::vector<pkgCache::DepIterator> &toInstall, APT::PackageVector *const toMoveAuto, bool const propagateProctected) /*{{{*/
 {
    auto const IsSatisfiedByInstalled = [&](auto const D) { return (DepState[D.ID] & DepInstall) == DepInstall; };
    for (auto &&Dep : toInstall)
@@ -1286,7 +1286,7 @@ bool pkgDepCache::MarkInstall_InstallDependencies(PkgIterator const &Pkg, unsign
 	 if (DebugAutoInstall)
 	    std::clog << OutputInDepth(Depth) << "Installing " << InstPkg.FullName()
 		      << " as " << End.DepType() << " of " << Pkg.FullName() << '\n';
-	 if (IsCriticalDep && toUpgrade.size() == 1 && PkgState[Pkg->ID].Protect())
+	 if (propagateProctected && IsCriticalDep && toUpgrade.size() == 1)
 	 {
 	    if (not MarkInstall(InstPkg, false, Depth + 1, false, ForceImportantDeps))
 	       continue;
@@ -1303,9 +1303,9 @@ bool pkgDepCache::MarkInstall_InstallDependencies(PkgIterator const &Pkg, unsign
       }
       if (not foundSolution && IsCriticalDep)
       {
-	 StateCache &State = PkgState[Pkg->ID];
-	 if (not State.Protect())
+	 if (not propagateProctected)
 	 {
+	    StateCache &State = PkgState[Pkg->ID];
 	    RemoveSizes(Pkg);
 	    RemoveStates(Pkg);
 	    if (Pkg->CurrentVer != 0)
@@ -1380,7 +1380,26 @@ bool pkgDepCache::MarkInstall(PkgIterator const &Pkg, bool AutoInst,
    if (DebugMarker)
       std::clog << OutputInDepth(Depth) << "MarkInstall " << APT::PrettyPkg(this, Pkg) << " FU=" << FromUser << '\n';
 
-   if (not MarkInstall_UpgradeOrRemoveConflicts(Pkg, Depth, ForceImportantDeps, toUpgrade))
+   class ScopedProtected
+   {
+      pkgDepCache::StateCache &P;
+      bool const already;
+
+      public:
+      ScopedProtected(pkgDepCache::StateCache &p) : P{p}, already{P.Protect()}
+      {
+	 if (not already)
+	    P.iFlags |= Protected;
+      }
+      ~ScopedProtected()
+      {
+	 if (not already)
+	    P.iFlags &= (~Protected);
+      }
+      operator bool() noexcept { return already; }
+   } propagateProctected{PkgState[Pkg->ID]};
+
+   if (not MarkInstall_UpgradeOrRemoveConflicts(propagateProctected, Depth, ForceImportantDeps, toUpgrade))
       return false;
 
    bool const MoveAutoBitToDependencies = [&]() {
@@ -1400,7 +1419,7 @@ bool pkgDepCache::MarkInstall(PkgIterator const &Pkg, bool AutoInst,
    }();
 
    APT::PackageVector toMoveAuto;
-   if (not MarkInstall_InstallDependencies(Pkg, Depth, ForceImportantDeps, toInstall, MoveAutoBitToDependencies ? &toMoveAuto : nullptr))
+   if (not MarkInstall_InstallDependencies(Pkg, Depth, ForceImportantDeps, toInstall, MoveAutoBitToDependencies ? &toMoveAuto : nullptr, propagateProctected))
       return false;
 
    if (MoveAutoBitToDependencies)
diff --git a/apt-pkg/depcache.h b/apt-pkg/depcache.h
index 339686b95..1579fedbe 100644
--- a/apt-pkg/depcache.h
+++ b/apt-pkg/depcache.h
@@ -521,8 +521,8 @@ class APT_PUBLIC pkgDepCache : protected pkgCache::Namespace
    APT_HIDDEN bool MarkInstall_StateChange(PkgIterator const &Pkg, bool AutoInst, bool FromUser);
    APT_HIDDEN bool MarkInstall_CollectDependencies(pkgCache::VerIterator const &PV, std::vector<pkgCache::DepIterator> &toInstall, std::vector<pkgCache::DepIterator> &toRemove);
    APT_HIDDEN bool MarkInstall_RemoveConflictsIfNotUpgradeable(pkgCache::VerIterator const &PV, unsigned long Depth, std::vector<pkgCache::DepIterator> &toRemove, APT::PackageVector &toUpgrade);
-   APT_HIDDEN bool MarkInstall_UpgradeOrRemoveConflicts(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, APT::PackageVector &toUpgrade);
-   APT_HIDDEN bool MarkInstall_InstallDependencies(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, std::vector<pkgCache::DepIterator> &toInstall, APT::PackageVector *const toMoveAuto);
+   APT_HIDDEN bool MarkInstall_UpgradeOrRemoveConflicts(bool const propagateProtected, unsigned long Depth, bool const ForceImportantDeps, APT::PackageVector &toUpgrade);
+   APT_HIDDEN bool MarkInstall_InstallDependencies(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, std::vector<pkgCache::DepIterator> &toInstall, APT::PackageVector *const toMoveAuto, bool const propagateProtected);
 };
 
 #endif
diff --git a/test/integration/test-allow-scores-for-all-dependency-types b/test/integration/test-allow-scores-for-all-dependency-types
index 9b300b7a7..b8a9ed3ea 100755
--- a/test/integration/test-allow-scores-for-all-dependency-types
+++ b/test/integration/test-allow-scores-for-all-dependency-types
@@ -116,42 +116,18 @@ Conf baz (2 unversioned [amd64])' aptget install baz -st unversioned
 testsuccessequal 'Reading package lists...
 Building dependency tree...
 The following additional packages will be installed:
-  foo
-The following packages will be REMOVED:
   bar
-The following NEW packages will be installed:
-  baz
-The following packages will be upgraded:
-  foo
-1 upgraded, 1 newly installed, 1 to remove and 0 not upgraded.
-Remv bar [1]
-Inst foo [1] (2 versioned [amd64])
-Inst baz (2 versioned [amd64])
-Conf foo (2 versioned [amd64])
-Conf baz (2 versioned [amd64])' aptget install baz -st versioned
-
-testsuccessequal 'Reading package lists...
-Building dependency tree...
-The following NEW packages will be installed:
-  baz
-0 upgraded, 1 newly installed, 0 to remove and 2 not upgraded.
-Inst baz (2 unversioned [amd64])
-Conf baz (2 unversioned [amd64])' aptget install baz -st unversioned
-testsuccessequal 'Reading package lists...
-Building dependency tree...
-The following additional packages will be installed:
-  foo
 The following packages will be REMOVED:
-  bar
+  foo
 The following NEW packages will be installed:
   baz
 The following packages will be upgraded:
-  foo
+  bar
 1 upgraded, 1 newly installed, 1 to remove and 0 not upgraded.
-Remv bar [1]
-Inst foo [1] (2 versioned [amd64])
+Remv foo [1]
+Inst bar [1] (2 versioned [amd64])
 Inst baz (2 versioned [amd64])
-Conf foo (2 versioned [amd64])
+Conf bar (2 versioned [amd64])
 Conf baz (2 versioned [amd64])' aptget install baz -st versioned
 
 # recreating the exact situation is hard, so we pull tricks to get the score
diff --git a/test/integration/test-explore-or-groups-in-markinstall b/test/integration/test-explore-or-groups-in-markinstall
index 259155854..5669e47b3 100755
--- a/test/integration/test-explore-or-groups-in-markinstall
+++ b/test/integration/test-explore-or-groups-in-markinstall
@@ -15,6 +15,10 @@ insertpackage 'unstable' 'bad-level0' 'all' '1' 'Depends: unneeded, unknown'
 insertpackage 'unstable' 'bad-level1' 'all' '1' 'Depends: bad-level0'
 insertpackage 'unstable' 'bad-upgrade-level0' 'all' '2' 'Depends: unneeded, unknown'
 insertpackage 'unstable' 'bad-upgrade-level1' 'all' '2' 'Depends: bad-upgrade-level0 (>= 2)'
+insertpackage 'unstable' 'bad-conflict-level0' 'all' '1' 'Depends: unneeded
+Conflicts: bad-conflict-level2'
+insertpackage 'unstable' 'bad-conflict-level1' 'all' '1' 'Depends: bad-conflict-level0'
+insertpackage 'unstable' 'bad-conflict-level2' 'all' '1' 'Depends: bad-conflict-level1'
 
 insertinstalledpackage 'upgrade' 'all' '1'
 insertinstalledpackage 'bad-upgrade' 'all' '1'
@@ -29,6 +33,8 @@ insertfoos() {
 	insertpackage 'unstable' "foo-${1}-upgrade-level0" 'all' '1' "${2}: bad-upgrade (>= 2) | okay | upgrade (>= 2) | later"
 	insertpackage 'unstable' "foo-${1}-upgrade-level1" 'all' '1' "${2}: bad-upgrade-level0 (>= 2) | bad-upgrade-level0 (>= 2) | bad-level0 | okay | upgrade (>= 2) | later"
 	insertpackage 'unstable' "foo-${1}-upgrade-level2" 'all' '1' "${2}: bad-upgrade-level1 (>= 2) | bad-upgrade-level1 (>= 2) | bad-level1 | okay | upgrade (>= 2) | later"
+
+	insertpackage 'unstable' "foo-${1}-conflict" 'all' '1' "${2}: unknown | bad-conflict-level2 | okay | later"
 }
 insertfoos 'd' 'Depends'
 insertfoos 'r' 'Recommends'
@@ -65,6 +71,14 @@ The following packages will be upgraded:
   upgrade
 1 upgraded, 1 newly installed, 0 to remove and $((2-${level})) not upgraded." apt install foo-${1}-upgrade-level${level} -s
 	done
+
+	testsuccessheadequal 7 "Reading package lists...
+Building dependency tree...
+The following additional packages will be installed:
+  okay
+The following NEW packages will be installed:
+  foo-${1}-conflict okay
+0 upgraded, 2 newly installed, 0 to remove and 3 not upgraded." apt install foo-${1}-conflict -s
 }
 checkfoos 'd' 'Depends'
 checkfoos 'r' 'Recommends'