From fcf8e293dd83248e7886ed204364fbc9f77667f6 Mon Sep 17 00:00:00 2001
From: Michael Andres <ma@suse.de>
Date: Tue, 22 Sep 2009 20:32:03 +0200
Subject: [PATCH] Add Selectable::updateCandidateObj returning the candidate
 for update, if there is one.

---
 zypp/ui/Selectable.cc    |  3 +++
 zypp/ui/Selectable.h     | 11 ++++++++++-
 zypp/ui/SelectableImpl.h | 35 ++++++++++++++++++++++++++++++++++-
 3 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/zypp/ui/Selectable.cc b/zypp/ui/Selectable.cc
index 2588faa..62bf2ea 100644
--- a/zypp/ui/Selectable.cc
+++ b/zypp/ui/Selectable.cc
@@ -73,6 +73,9 @@ namespace zypp
     PoolItem Selectable::candidateObj() const
     { return _pimpl->candidateObj(); }
 
+    PoolItem Selectable::updateCandidateObj() const
+    { return _pimpl->updateCandidateObj(); }
+
     PoolItem Selectable::setCandidate( const PoolItem & newCandidate_r, ResStatus::TransactByValue causer_r )
     { return _pimpl->setCandidate( newCandidate_r, causer_r ); }
 
diff --git a/zypp/ui/Selectable.h b/zypp/ui/Selectable.h
index a300eaa..c5cd548 100644
--- a/zypp/ui/Selectable.h
+++ b/zypp/ui/Selectable.h
@@ -120,10 +120,19 @@ namespace zypp
       PoolItem installedObj() const;
 
       /** The 'best' or 'most interesting' among all available objects.
-       * One that is, or is likely to be, chosen for installation.
+       * One that is, or is likely to be, chosen for installation, unless
+       * it violated any solver policy (see \ref updateCandidateObj).
        */
       PoolItem candidateObj() const;
 
+      /** The best candidate for update, if there is one.
+       * In contrary to \ref candidateObj, this may return no item even if
+       * there are available objects. This simply means the best object is
+       * already installed, and all available objects violate at least one
+       * update policy.
+       */
+      PoolItem updateCandidateObj() const;
+
       /** Return the \ref installedObj resolvable casted to a specific kind.
        * \code
        *   Selectable mySelectable;
diff --git a/zypp/ui/SelectableImpl.h b/zypp/ui/SelectableImpl.h
index 8b71ae7..53f4db8 100644
--- a/zypp/ui/SelectableImpl.h
+++ b/zypp/ui/SelectableImpl.h
@@ -117,6 +117,39 @@ namespace zypp
       */
       PoolItem setCandidate( const PoolItem & newCandidate_r, ResStatus::TransactByValue causer_r );
 
+      /** The best candidate for update, if there is one.
+       * In contrary to \ref candidateObj, this may return no item even if
+       * there are available objects. This simply means the best object is
+       * already installed, and all available objects violate at least one
+       * update policy.
+       */
+      PoolItem updateCandidateObj() const
+      {
+        if ( installedEmpty() || ! _defaultCandidate )
+          return _defaultCandidate;
+        // Here: installed and _defaultCandidate are non NULL.
+
+        // update candidate must come from the highest priority repo
+        if ( _defaultCandidate->repoInfo().priority() != (*availableBegin())->repoInfo().priority() )
+          return PoolItem();
+
+        PoolItem installed( installedObj() );
+        // check vendor change
+        if ( ! ( ZConfig::instance().solver_allowVendorChange()
+                 || VendorAttr::instance().equivalent( _defaultCandidate->vendor(), installed->vendor() ) ) )
+          return PoolItem();
+
+        // check arch change
+        if ( _defaultCandidate->arch() != installed->arch() )
+          return PoolItem();
+
+        // check greater edition
+        if ( _defaultCandidate->edition() <= installed->edition() )
+          return PoolItem();
+
+        return _defaultCandidate;
+      }
+
       /** Best among all objects. */
       PoolItem theObj() const
       {
@@ -141,7 +174,6 @@ namespace zypp
       available_const_iterator availableBegin() const
       { return _availableItems.begin(); }
 
-
       available_const_iterator availableEnd() const
       { return _availableItems.end(); }
 
@@ -263,6 +295,7 @@ namespace zypp
       AvailableItemSet       _availableItems;
       //! Best among availabe with restpect to installed.
       PoolItem               _defaultCandidate;
+
       //! The object selected by setCandidateObj() method.
       PoolItem               _candidate;
     };
-- 
2.7.4