Fix bad merge of D16791 and D16767

Summary: A bad Auto-Merge caused log buffer is flushed twice. Remove the unintended one.

Test Plan: Should already be tested (the code looks the same as when I ran unit tests).

Reviewers: haobo, igor

Reviewed By: haobo

CC: ljin, yhchiang, leveldb

Differential Revision: https://reviews.facebook.net/D16821

tools/db_repl_stress.cc

@@ -67,8 +67,21 @@ static void ReplicationThreadBody(void* arg) {
       }
     }
     fprintf(stderr, "Refreshing iterator\n");
-    for(;iter->Valid(); iter->Next(), t->no_read++, currentSeqNum++) {
+    for (; !iter->IsObsolete(); iter->Next()) {
+      if (!iter->Valid()) {
+        if (t->stop.Acquire_Load() == nullptr) {
+          return;
+        }
+        // need to wait for new rows.
+        continue;
+      }
+
       BatchResult res = iter->GetBatch();
+      if (!iter->status().ok()) {
+        fprintf(stderr, "Corruption reported when reading seq no. b/w %ld",
+                static_cast<uint64_t>(currentSeqNum));
+        exit(1);
+      }
       if (res.sequence != currentSeqNum) {
         fprintf(stderr,
                 "Missed a seq no. b/w %ld and %ld\n",
@@ -76,6 +89,8 @@ static void ReplicationThreadBody(void* arg) {
                 (long)res.sequence);
         exit(1);
       }
+      t->no_read++;
+      currentSeqNum++;
     }
   }
 }