3 files changed, 39 insertions, 4 deletions
diff --git a/src/libs/installer/genericdatacache.cpp b/src/libs/installer/genericdatacache.cpp
index 7f21a5365..1b33976c8 100644
--- a/src/libs/installer/genericdatacache.cpp
+++ b/src/libs/installer/genericdatacache.cpp
@@ -112,6 +112,11 @@ CacheableItem::~CacheableItem()
     methods declared in the \l{CacheableItem} interface. The GenericDataCache\<T\> class can
     still be explicitly specialized to use the derived type as a template argument, to
     allow retrieving items as the derived type without casting.
+
+    Each cache has a manifest file in its root directory, which lists the version
+    and wrapped type of the cache, and all its items. The file is updated automatically
+    when the cache object is destructed, or it can be updated periodically by
+    calling \l{sync()}.
 */
 
 /*!
@@ -273,6 +278,23 @@ bool GenericDataCache<T>::clear()
 }
 
 /*!
+   \fn template <typename T> QInstaller::GenericDataCache<T>::sync()
+
+    Synchronizes the contents of the cache to its manifest file. Returns \c true
+    if the manifest file was updates successfully, \c false otherwise.
+*/
+template<typename T>
+bool GenericDataCache<T>::sync()
+{
+    if (m_invalidated) {
+        setErrorString(QCoreApplication::translate("GenericDataCache",
+            "Cannot synchronize invalidated cache."));
+        return false;
+    }
+    return toDisk();
+}
+
+/*!
    \fn template <typename T> QInstaller::GenericDataCache<T>::isValid() const
 
    Returns \c true if the cache is valid, \c false otherwise. A cache is considered
diff --git a/src/libs/installer/genericdatacache.h b/src/libs/installer/genericdatacache.h
index 7b909cc7a..5042ed9a4 100644
--- a/src/libs/installer/genericdatacache.h
+++ b/src/libs/installer/genericdatacache.h
@@ -72,6 +72,7 @@ public:
 
     bool initialize();
     bool clear();
+    bool sync();
 
     bool isValid() const;
     QString errorString() const;
diff --git a/src/libs/installer/metadatajob.cpp b/src/libs/installer/metadatajob.cpp
index a15209a31..659648e1a 100644
--- a/src/libs/installer/metadatajob.cpp
+++ b/src/libs/installer/metadatajob.cpp
@@ -346,12 +346,11 @@ bool MetadataJob::updateCache()
 
     // Register items from current run to cache
     QStringList registeredKeys;
+    bool success = true;
     for (auto *meta : qAsConst(m_fetchedMetadata)) {
         if (!m_metaFromCache.registerItem(meta, true)) {
-            emitFinishedWithError(QInstaller::CacheError, m_metaFromCache.errorString()
-                + u' '
-                + tr("Clearing the cache directory and restarting the application may solve this."));
-            return false;
+            success = false;
+            break;
         }
         meta->setPersistentRepositoryPath(meta->repository().url());
         registeredKeys.append(m_fetchedMetadata.key(meta));
@@ -360,11 +359,24 @@ bool MetadataJob::updateCache()
     for (auto &key : qAsConst(registeredKeys))
         m_fetchedMetadata.remove(key);
 
+    // Bail out if there was error while registering items
+    if (!success) {
+        emitFinishedWithError(QInstaller::CacheError, m_metaFromCache.errorString() + u' '
+            + tr("Clearing the cache directory and restarting the application may solve this."));
+        m_metaFromCache.sync();
+        return false;
+    }
+
     // ...and clean up obsolete cached items
     const QList<Metadata *> obsolete = m_metaFromCache.obsoleteItems();
     for (auto *meta : obsolete)
         m_metaFromCache.removeItem(meta->checksum());
 
+    if (!m_metaFromCache.sync()) {
+        emitFinishedWithError(QInstaller::CacheError, m_metaFromCache.errorString() + u' '
+            + tr("Clearing the cache directory and restarting the application may solve this."));
+        return false;
+    }
     return true;
 }