1 files changed, 5 insertions, 3 deletions
diff --git a/libfuzzer/FuzzerMerge.cpp b/libfuzzer/FuzzerMerge.cpp
index e3ad8b3..162453c 100644
--- a/libfuzzer/FuzzerMerge.cpp
+++ b/libfuzzer/FuzzerMerge.cpp
@@ -82,9 +82,9 @@ bool Merger::Parse(std::istream &IS, bool ParseCoverage) {
   while (std::getline(IS, Line, '\n')) {
     std::istringstream ISS1(Line);
     std::string Marker;
-    size_t N;
-    ISS1 >> Marker;
-    ISS1 >> N;
+    uint32_t N;
+    if (!(ISS1 >> Marker) || !(ISS1 >> N))
+      return false;
     if (Marker == "STARTED") {
       // STARTED FILE_ID FILE_SIZE
       if (ExpectedStartMarker != N)
@@ -137,6 +137,8 @@ size_t Merger::Merge(const Set<uint32_t> &InitialFeatures,
                      const Set<uint32_t> &InitialCov, Set<uint32_t> *NewCov,
                      Vector<std::string> *NewFiles) {
   NewFiles->clear();
+  NewFeatures->clear();
+  NewCov->clear();
   assert(NumFilesInFirstCorpus <= Files.size());
   Set<uint32_t> AllFeatures = InitialFeatures;