fix: last restorable subspace was not initialized

fdbclient/BackupAgent.h

@@ -277,6 +277,8 @@ public:
 	static std::string getDataFilename(Version version, int64_t size, int blockSize);
 	static std::string getLogFilename(Version beginVer, Version endVer, int64_t size, int blockSize);
 
+	static const Key keyLastRestorable;
+
 	Future<int64_t> getTaskCount(Reference<ReadYourWritesTransaction> tr) { return taskBucket->getTaskCount(tr); }
 	Future<int64_t> getTaskCount(Database cx) { return taskBucket->getTaskCount(cx); }
 	Future<Void> watchTaskCount(Reference<ReadYourWritesTransaction> tr) { return taskBucket->watchTaskCount(tr); }

fdbclient/FileBackupAgent.actor.cpp

@@ -35,6 +35,8 @@
 #include <boost/algorithm/string/classification.hpp>
 #include <algorithm>
 
+const Key FileBackupAgent::keyLastRestorable = LiteralStringRef("last_restorable");
+
 // For convenience
 typedef FileBackupAgent::ERestoreState ERestoreState;
 
@@ -304,6 +306,7 @@ FileBackupAgent::FileBackupAgent()
 	: subspace(Subspace(fileBackupPrefixRange.begin))
 	// The other subspaces have logUID -> value
 	, config(subspace.get(BackupAgentBase::keyConfig))
+	, lastRestorable(subspace.get(FileBackupAgent::keyLastRestorable))
 	, taskBucket(new TaskBucket(subspace.get(BackupAgentBase::keyTasks), true, false, true))
 	, futureBucket(new FutureBucket(subspace.get(BackupAgentBase::keyFutures), true, true))
 {