preserve per-package pre-release option when synchronizing

Author: cfillion

src/synchronize.cpp

@@ -96,5 +96,5 @@ void SynchronizeTask::synchronize(const Package *pkg)
   else if(entry.test(Registry::Entry::PinnedFlag) || latest->name() < entry.version)
     return;
 
-  tx()->install(latest, entry);
+  tx()->install(latest, entry, entry.flags);
 }

src/transaction.hpp

@@ -57,7 +57,7 @@ class Transaction {
     const std::optional<bool> &forceAutoInstall = std::nullopt);
   void install(const Version *, int flags = 0, const ArchiveReaderPtr & = nullptr);
   void install(const Version *, const Registry::Entry &oldEntry,
-    int flags = false, const ArchiveReaderPtr & = nullptr);
+    int flags = 0, const ArchiveReaderPtr & = nullptr);
   void setFlags(const Registry::Entry &, int flags);
   void uninstall(const Remote &);
   void uninstall(const Registry::Entry &);