Index: include/llvm/Support/YAMLParser.h
===================================================================
--- include/llvm/Support/YAMLParser.h
+++ include/llvm/Support/YAMLParser.h
@@ -75,9 +75,9 @@
 class Stream {
 public:
   /// \brief This keeps a reference to the string referenced by \p Input.
-  Stream(StringRef Input, SourceMgr &, bool ShowColors = true);
+  Stream(StringRef Input, SourceMgr &, bool ShowColors = true, std::error_code* EC = nullptr);
 
-  Stream(MemoryBufferRef InputBuffer, SourceMgr &, bool ShowColors = true);
+  Stream(MemoryBufferRef InputBuffer, SourceMgr &, bool ShowColors = true, std::error_code* EC = nullptr);
   ~Stream();
 
   document_iterator begin();
Index: lib/Support/YAMLParser.cpp
===================================================================
--- lib/Support/YAMLParser.cpp
+++ lib/Support/YAMLParser.cpp
@@ -232,8 +232,8 @@
 /// @brief Scans YAML tokens from a MemoryBuffer.
 class Scanner {
 public:
-  Scanner(StringRef Input, SourceMgr &SM, bool ShowColors = true);
-  Scanner(MemoryBufferRef Buffer, SourceMgr &SM_, bool ShowColors = true);
+  Scanner(StringRef Input, SourceMgr &SM, bool ShowColors = true, std::error_code *EC = nullptr);
+  Scanner(MemoryBufferRef Buffer, SourceMgr &SM_, bool ShowColors = true, std::error_code *EC = nullptr);
 
   /// @brief Parse the next token and return it without popping it.
   Token &peekNext();
@@ -250,11 +250,16 @@
     if (Current >= End)
       Current = End - 1;
 
+    // propagate the error if possible
+    if(EC)
+      *EC = make_error_code(std::errc::invalid_argument);
+
     // Don't print out more errors after the first one we encounter. The rest
     // are just the result of the first, and have no meaning.
     if (!Failed)
       printError(SMLoc::getFromPointer(Current), SourceMgr::DK_Error, Message);
     Failed = true;
+
   }
 
   void setError(const Twine &Message) {
@@ -528,6 +533,8 @@
 
   /// @brief Potential simple keys.
   SmallVector<SimpleKey, 4> SimpleKeys;
+
+  std::error_code *EC;
 };
 
 } // end namespace yaml
@@ -722,13 +729,13 @@
   return EscapedInput;
 }
 
-Scanner::Scanner(StringRef Input, SourceMgr &sm, bool ShowColors)
-    : SM(sm), ShowColors(ShowColors) {
+Scanner::Scanner(StringRef Input, SourceMgr &sm, bool ShowColors, std::error_code *EC)
+    : SM(sm), ShowColors(ShowColors), EC(EC) {
   init(MemoryBufferRef(Input, "YAML"));
 }
 
-Scanner::Scanner(MemoryBufferRef Buffer, SourceMgr &SM_, bool ShowColors)
-    : SM(SM_), ShowColors(ShowColors) {
+Scanner::Scanner(MemoryBufferRef Buffer, SourceMgr &SM_, bool ShowColors, std::error_code *EC)
+    : SM(SM_), ShowColors(ShowColors), EC(EC) {
   init(Buffer);
 }
 
@@ -1726,11 +1733,11 @@
   return false;
 }
 
-Stream::Stream(StringRef Input, SourceMgr &SM, bool ShowColors)
-    : scanner(new Scanner(Input, SM, ShowColors)), CurrentDoc() {}
+Stream::Stream(StringRef Input, SourceMgr &SM, bool ShowColors, std::error_code *EC)
+    : scanner(new Scanner(Input, SM, ShowColors, EC)), CurrentDoc() {}
 
-Stream::Stream(MemoryBufferRef InputBuffer, SourceMgr &SM, bool ShowColors)
-    : scanner(new Scanner(InputBuffer, SM, ShowColors)), CurrentDoc() {}
+Stream::Stream(MemoryBufferRef InputBuffer, SourceMgr &SM, bool ShowColors, std::error_code *EC)
+    : scanner(new Scanner(InputBuffer, SM, ShowColors, EC)), CurrentDoc() {}
 
 Stream::~Stream() {}
 
@@ -1741,6 +1748,7 @@
                      , SourceMgr::DK_Error
                      , Msg
                      , N->getSourceRange());
+
 }
 
 document_iterator Stream::begin() {
Index: lib/Support/YAMLTraits.cpp
===================================================================
--- lib/Support/YAMLTraits.cpp
+++ lib/Support/YAMLTraits.cpp
@@ -49,7 +49,7 @@
              SourceMgr::DiagHandlerTy DiagHandler,
              void *DiagHandlerCtxt)
   : IO(Ctxt),
-    Strm(new Stream(InputContent, SrcMgr)),
+    Strm(new Stream(InputContent, SrcMgr, false, &EC)),
     CurrentNode(nullptr) {
   if (DiagHandler)
     SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
Index: unittests/Support/YAMLIOTest.cpp
===================================================================
--- unittests/Support/YAMLIOTest.cpp
+++ unittests/Support/YAMLIOTest.cpp
@@ -2368,3 +2368,11 @@
             out);
   out.clear();
 }
+
+TEST(YAMLIO, InvalidInput) {
+  // polluting 1 value in the sequence
+  Input yin("---\n- foo:  3\n  bar:  5\n1\n- foo:  3\n  bar:  5\n...\n");
+  std::vector<FooBar> Data;
+  yin >> Data;
+  EXPECT_TRUE((bool)yin.error());
+}