Merge src/leveldb changes for LevelDB 1.13

src/leveldb/util/env_posix.cc

@@ -320,8 +320,39 @@ class PosixMmapFile : public WritableFile {
     return Status::OK();
   }
 
-  virtual Status Sync() {
+  Status SyncDirIfManifest() {
+    const char* f = filename_.c_str();
+    const char* sep = strrchr(f, '/');
+    Slice basename;
+    std::string dir;
+    if (sep == NULL) {
+      dir = ".";
+      basename = f;
+    } else {
+      dir = std::string(f, sep - f);
+      basename = sep + 1;
+    }
     Status s;
+    if (basename.starts_with("MANIFEST")) {
+      int fd = open(dir.c_str(), O_RDONLY);
+      if (fd < 0) {
+        s = IOError(dir, errno);
+      } else {
+        if (fsync(fd) < 0) {
+          s = IOError(dir, errno);
+        }
+        close(fd);
+      }
+    }
+    return s;
+  }
+
+  virtual Status Sync() {
+    // Ensure new files referred to by the manifest are in the filesystem.
+    Status s = SyncDirIfManifest();
+    if (!s.ok()) {
+      return s;
+    }
 
     if (pending_sync_) {
       // Some unmapped data was not synced

src/leveldb/util/random.h

@@ -16,7 +16,12 @@ class Random {
  private:
   uint32_t seed_;
  public:
-  explicit Random(uint32_t s) : seed_(s & 0x7fffffffu) { }
+  explicit Random(uint32_t s) : seed_(s & 0x7fffffffu) {
+    // Avoid bad seeds.
+    if (seed_ == 0 || seed_ == 2147483647L) {
+      seed_ = 1;
+    }
+  }
   uint32_t Next() {
     static const uint32_t M = 2147483647L;   // 2^31-1
     static const uint64_t A = 16807;  // bits 14, 8, 7, 5, 2, 1, 0