From 54823d82a1369c25ba1a68c18ea2a67c41f4fbe7 Mon Sep 17 00:00:00 2001
From: Jan Kolarik <jkolarik@redhat.com>
Date: Mon, 26 Feb 2024 09:58:33 +0000
Subject: [PATCH] MergedTransaction: Calculate RPM difference between two same
 versions as no-op

If a package of a particular version is installed and would still be installed after a list of transactions, it's more user friendly to treat the whole situation as "do nothing".

Conflict:NA
Reference:https://github.com/rpm-software-management/libdnf/commit/54823d82a1369c25ba1a68c18ea2a67c41f4fbe7
---
 libdnf/transaction/MergedTransaction.cpp      | 38 ++++++++++++-------
 libdnf/transaction/MergedTransaction.hpp      |  6 +--
 .../transaction/MergedTransactionTest.cpp     |  7 +---
 3 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/libdnf/transaction/MergedTransaction.cpp b/libdnf/transaction/MergedTransaction.cpp
index a8d878cb51..8f26882f71 100644
--- a/libdnf/transaction/MergedTransaction.cpp
+++ b/libdnf/transaction/MergedTransaction.cpp
@@ -192,7 +192,7 @@ static bool transaction_item_sort_function(const std::shared_ptr<TransactionItem
  * Actions are merged using following rules:
  * (old action) -> (new action) = (merged action)
  *
- * Erase/Obsolete -> Install/Obsoleting = Reinstall/Downgrade/Upgrade
+ * Erase/Obsolete -> Install/Obsoleting = Downgrade/Upgrade
  *
  * Reinstall/Reason change -> (new action) = (new action)
  *
@@ -210,6 +210,9 @@ static bool transaction_item_sort_function(const std::shared_ptr<TransactionItem
  *
  *      With complete transaction pair we need to get a new Upgrade/Downgrade package and
  *      compare versions with original package from pair.
+ *
+ * Additionally, if a package is installed both before and after the list of transactions
+ * with the same version, no action will be taken.
  */
 std::vector< TransactionItemBasePtr >
 MergedTransaction::getItems()
@@ -261,13 +264,16 @@ getItemIdentifier(ItemPtr item)
 
 /**
  * Resolve the difference between RPMs in the first and second transaction item
- *  and create a ItemPair of Upgrade, Downgrade or reinstall.
+ *  and create a ItemPair of Upgrade, Downgrade or drop the item from the merged
+ *  transaction set in case of both packages are of the same version.
  * Method is called when original package is being removed and than installed again.
+ * \param itemPairMap merged transaction set
  * \param previousItemPair original item pair
  * \param mTransItem new transaction item
  */
 void
-MergedTransaction::resolveRPMDifference(ItemPair &previousItemPair,
+MergedTransaction::resolveRPMDifference(ItemPairMap &itemPairMap,
+                                        ItemPair &previousItemPair,
                                         TransactionItemBasePtr mTransItem)
 {
     auto firstItem = previousItemPair.first->getItem();
@@ -277,11 +283,10 @@ MergedTransaction::resolveRPMDifference(ItemPair &previousItemPair,
     auto secondRPM = std::dynamic_pointer_cast< RPMItem >(secondItem);
 
     if (firstRPM->getVersion() == secondRPM->getVersion() &&
-        firstRPM->getEpoch() == secondRPM->getEpoch()) {
-        // reinstall
-        mTransItem->setAction(TransactionItemAction::REINSTALL);
-        previousItemPair.first = mTransItem;
-        previousItemPair.second = nullptr;
+        firstRPM->getEpoch() == secondRPM->getEpoch() &&
+        firstRPM->getRelease() == secondRPM->getRelease()) {
+        // Drop the item from merged transaction
+        itemPairMap.erase(getItemIdentifier(firstItem));
         return;
     } else if ((*firstRPM) < (*secondRPM)) {
         // Upgrade to secondRPM
@@ -296,7 +301,9 @@ MergedTransaction::resolveRPMDifference(ItemPair &previousItemPair,
 }
 
 void
-MergedTransaction::resolveErase(ItemPair &previousItemPair, TransactionItemBasePtr mTransItem)
+MergedTransaction::resolveErase(ItemPairMap &itemPairMap,
+                                ItemPair &previousItemPair,
+                                TransactionItemBasePtr mTransItem)
 {
     /*
      * The original item has been removed - it has to be installed now unless the rpmdb
@@ -306,7 +313,7 @@ MergedTransaction::resolveErase(ItemPair &previousItemPair, TransactionItemBaseP
     if (mTransItem->getAction() == TransactionItemAction::INSTALL) {
         if (mTransItem->getItem()->getItemType() == ItemType::RPM) {
             // resolve the difference between RPM packages
-            resolveRPMDifference(previousItemPair, mTransItem);
+            resolveRPMDifference(itemPairMap, previousItemPair, mTransItem);
         } else {
             // difference between comps can't be resolved
             mTransItem->setAction(TransactionItemAction::REINSTALL);
@@ -323,11 +330,14 @@ MergedTransaction::resolveErase(ItemPair &previousItemPair, TransactionItemBaseP
  * transaction - new package is used to complete the pair. Items are stored in pairs (Upgrade,
  * Upgrade) or (Downgraded, Downgrade). With complete transaction pair we need to get the new
  * Upgrade/Downgrade item and compare its version with the original item from the pair.
+ * \param itemPairMap merged transaction set
  * \param previousItemPair original item pair
  * \param mTransItem new transaction item
  */
 void
-MergedTransaction::resolveAltered(ItemPair &previousItemPair, TransactionItemBasePtr mTransItem)
+MergedTransaction::resolveAltered(ItemPairMap &itemPairMap,
+                                  ItemPair &previousItemPair,
+                                  TransactionItemBasePtr mTransItem)
 {
     auto newState = mTransItem->getAction();
     auto firstState = previousItemPair.first->getAction();
@@ -369,7 +379,7 @@ MergedTransaction::resolveAltered(ItemPair &previousItemPair, TransactionItemBas
         } else {
             if (mTransItem->getItem()->getItemType() == ItemType::RPM) {
                 // resolve the difference between RPM packages
-                resolveRPMDifference(previousItemPair, mTransItem);
+                resolveRPMDifference(itemPairMap, previousItemPair, mTransItem);
             } else {
                 // difference between comps can't be resolved
                 previousItemPair.second->setAction(TransactionItemAction::REINSTALL);
@@ -405,7 +415,7 @@ MergedTransaction::mergeItem(ItemPairMap &itemPairMap, TransactionItemBasePtr mT
     switch (firstState) {
         case TransactionItemAction::REMOVE:
         case TransactionItemAction::OBSOLETED:
-            resolveErase(previousItemPair, mTransItem);
+            resolveErase(itemPairMap, previousItemPair, mTransItem);
             break;
         case TransactionItemAction::INSTALL:
             // the original package has been installed -> it may be either Removed, or altered
@@ -432,7 +442,7 @@ MergedTransaction::mergeItem(ItemPairMap &itemPairMap, TransactionItemBasePtr mT
         case TransactionItemAction::UPGRADE:
         case TransactionItemAction::UPGRADED:
         case TransactionItemAction::OBSOLETE:
-            resolveAltered(previousItemPair, mTransItem);
+            resolveAltered(itemPairMap, previousItemPair, mTransItem);
             break;
         case TransactionItemAction::REINSTALLED:
             break;
diff --git a/libdnf/transaction/MergedTransaction.hpp b/libdnf/transaction/MergedTransaction.hpp
index dbb8af1183..f85b133a87 100644
--- a/libdnf/transaction/MergedTransaction.hpp
+++ b/libdnf/transaction/MergedTransaction.hpp
@@ -76,9 +76,9 @@ class MergedTransaction {
     typedef std::map< std::string, ItemPair > ItemPairMap;
 
     void mergeItem(ItemPairMap &itemPairMap, TransactionItemBasePtr transItem);
-    void resolveRPMDifference(ItemPair &previousItemPair, TransactionItemBasePtr mTransItem);
-    void resolveErase(ItemPair &previousItemPair, TransactionItemBasePtr mTransItem);
-    void resolveAltered(ItemPair &previousItemPair, TransactionItemBasePtr mTransItem);
+    void resolveRPMDifference(ItemPairMap &itemPairMap, ItemPair &previousItemPair, TransactionItemBasePtr mTransItem);
+    void resolveErase(ItemPairMap &itemPairMap, ItemPair &previousItemPair, TransactionItemBasePtr mTransItem);
+    void resolveAltered(ItemPairMap &itemPairMap, ItemPair &previousItemPair, TransactionItemBasePtr mTransItem);
 };
 
 } // namespace libdnf
diff --git a/tests/libdnf/transaction/MergedTransactionTest.cpp b/tests/libdnf/transaction/MergedTransactionTest.cpp
index 52507700bc..35fb4250e4 100644
--- a/tests/libdnf/transaction/MergedTransactionTest.cpp
+++ b/tests/libdnf/transaction/MergedTransactionTest.cpp
@@ -822,12 +822,7 @@ MergedTransactionTest::test_downgrade_upgrade_remove()
     // test merging trans1, trans2
     merged.merge(trans2);
     auto items2 = merged.getItems();
-    CPPUNIT_ASSERT_EQUAL(1, (int)items2.size());
-    auto item2 = items2.at(0);
-    CPPUNIT_ASSERT_EQUAL(std::string("tour-4.8-1.noarch"), item2->getItem()->toStr());
-    CPPUNIT_ASSERT_EQUAL(std::string("repo1"), item2->getRepoid());
-    CPPUNIT_ASSERT_EQUAL(TransactionItemAction::REINSTALL, item2->getAction());
-    CPPUNIT_ASSERT_EQUAL(TransactionItemReason::USER, item2->getReason());
+    CPPUNIT_ASSERT_EQUAL(0, (int)items2.size());
 
     // test merging trans1, trans2, trans3
     merged.merge(trans3);
