transaction: Don't remove cache when no inbound action

When the `keepcache` option is turned off, the packages downloaded during a previous command should still be preserved until a subsequent successful transaction that involves inbound actions such as installation or upgrading. This assumption is based on the idea that these packages were downloaded for this purpose.

As a result, temporary packages are retained even across transactions that do not involve any inbound actions.

This feature is also valuable in cases where a previous transaction downloaded a substantial amount of data but did not complete correctly. In such instances, we want to rectify the system state by removing problematic packages without losing our cached data.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2237883

libdnf5/base/transaction.cpp

@@ -524,6 +524,15 @@ static void process_scriptlets_output(int fd, Logger * logger) {
  close(fd);
 }
 
+static bool contains_any_inbound_package(std::vector<TransactionPackage> & packages) {
+ for (const auto & package : packages) {
+ if (transaction_item_action_is_inbound(package.get_action())) {
+ return true;
+ }
+ }
+ return false;
+}
+
 Transaction::TransactionRunResult Transaction::Impl::test() {
  return this->_run(std::make_unique<libdnf5::rpm::TransactionCallbacks>(), "", std::nullopt, "", true);
 }
@@ -869,7 +878,10 @@ Transaction::TransactionRunResult Transaction::Impl::_run(
 
  if (ret == 0) {
  // removes any temporarily stored packages from the system
- if (!config.get_keepcache_option().get_value()) {
+ // only if any inbound action takes place
+ auto keepcache = config.get_keepcache_option().get_value();
+ auto any_inbound_action_present = contains_any_inbound_package(packages);
+ if (!keepcache && any_inbound_action_present) {
  libdnf5::repo::TempFilesMemory temp_files_memory(config.get_cachedir_option().get_value());
  auto temp_files = temp_files_memory.get_files();
  for (auto & file : temp_files) {