Index: llvm/trunk/include/llvm/Support/CommandLine.h
===================================================================
--- llvm/trunk/include/llvm/Support/CommandLine.h
+++ llvm/trunk/include/llvm/Support/CommandLine.h
@@ -1425,6 +1425,8 @@
 public:
   list_storage() = default;
 
+  void clear() {}
+
   bool setLocation(Option &O, StorageClass &L) {
     if (Location)
       return O.error("cl::location(x) specified more than once!");
@@ -1476,6 +1478,10 @@
   reference operator[](size_type pos) { return Storage[pos]; }
   const_reference operator[](size_type pos) const { return Storage[pos]; }
 
+  void clear() {
+    Storage.clear();
+  }
+
   iterator erase(const_iterator pos) { return Storage.erase(pos); }
   iterator erase(const_iterator first, const_iterator last) {
     return Storage.erase(first, last);
@@ -1553,7 +1559,10 @@
   void printOptionValue(size_t /*GlobalWidth*/, bool /*Force*/) const override {
   }
 
-  void setDefault() override {}
+  void setDefault() override {
+    Positions.clear();
+    list_storage<DataType, StorageClass>::clear();
+  }
 
   void done() {
     addArgument();
Index: llvm/trunk/unittests/Support/CommandLineTest.cpp
===================================================================
--- llvm/trunk/unittests/Support/CommandLineTest.cpp
+++ llvm/trunk/unittests/Support/CommandLineTest.cpp
@@ -944,13 +944,21 @@
 }
 
 TEST(CommandLineTest, PositionalEatArgsError) {
+  cl::ResetCommandLineParser();
+
   StackOption<std::string, cl::list<std::string>> PosEatArgs(
       "positional-eat-args", cl::Positional, cl::desc("<arguments>..."),
       cl::ZeroOrMore, cl::PositionalEatsArgs);
+  StackOption<std::string, cl::list<std::string>> PosEatArgs2(
+      "positional-eat-args2", cl::Positional, cl::desc("Some strings"),
+      cl::ZeroOrMore, cl::PositionalEatsArgs);
 
   const char *args[] = {"prog", "-positional-eat-args=XXXX"};
   const char *args2[] = {"prog", "-positional-eat-args=XXXX", "-foo"};
   const char *args3[] = {"prog", "-positional-eat-args", "-foo"};
+  const char *args4[] = {"prog", "-positional-eat-args",
+                         "-foo", "-positional-eat-args2",
+                         "-bar", "foo"};
 
   std::string Errs;
   raw_string_ostream OS(Errs);
@@ -959,6 +967,12 @@
   EXPECT_FALSE(cl::ParseCommandLineOptions(3, args2, StringRef(), &OS)); OS.flush();
   EXPECT_FALSE(Errs.empty()); Errs.clear();
   EXPECT_TRUE(cl::ParseCommandLineOptions(3, args3, StringRef(), &OS)); OS.flush();
+  EXPECT_TRUE(Errs.empty()); Errs.clear();
+
+  cl::ResetAllOptionOccurrences();
+  EXPECT_TRUE(cl::ParseCommandLineOptions(6, args4, StringRef(), &OS)); OS.flush();
+  EXPECT_TRUE(PosEatArgs.size() == 1);
+  EXPECT_TRUE(PosEatArgs2.size() == 2);
   EXPECT_TRUE(Errs.empty());
 }