Index: include/llvm/Bitcode/BitstreamWriter.h
===================================================================
--- include/llvm/Bitcode/BitstreamWriter.h
+++ include/llvm/Bitcode/BitstreamWriter.h
@@ -367,6 +367,7 @@
           BlobData = nullptr;
         } else {
           emitBlob(Vals.slice(RecordIdx));
+          RecordIdx = Vals.size();
         }
       } else {  // Single scalar field.
         assert(RecordIdx < Vals.size() && "Invalid abbrev/record");
Index: unittests/Bitcode/BitstreamWriterTest.cpp
===================================================================
--- unittests/Bitcode/BitstreamWriterTest.cpp
+++ unittests/Bitcode/BitstreamWriterTest.cpp
@@ -8,8 +8,10 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Bitcode/BitstreamWriter.h"
+
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/Bitcode/BitCodes.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
@@ -56,4 +58,29 @@
   EXPECT_EQ(StringRef("str0"), Buffer);
 }
 
+TEST(BitstreamWriterTest, emitBlobFromArray) {
+  auto Abbrev = std::make_shared<BitCodeAbbrev>();
+  Abbrev->Add(BitCodeAbbrevOp(0));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
+  SmallString<64> Buffer;
+  {
+    SmallVector<uint64_t, 1> Vals = {0, 0x12, 0x34};
+    BitstreamWriter W(Buffer);
+    W.EnterSubblock(0, 3);
+    unsigned AbbrevID = W.EmitAbbrev(Abbrev);
+    W.EmitRecordWithAbbrev(AbbrevID, Vals);
+    W.ExitBlock();
+  }
+  SmallString<64> Expected;
+  {
+    SmallVector<uint64_t, 1> Vals = {0};
+    BitstreamWriter W(Expected);
+    W.EnterSubblock(0, 3);
+    unsigned AbbrevID = W.EmitAbbrev(Abbrev);
+    W.EmitRecordWithBlob(AbbrevID, Vals, "\x12\x34");
+    W.ExitBlock();
+  }
+  EXPECT_EQ(StringRef(Expected), Buffer);
+}
+
 } // end namespace