Index: clang-tools-extra/clangd/index/dex/Iterator.h
===================================================================
--- clang-tools-extra/clangd/index/dex/Iterator.h
+++ clang-tools-extra/clangd/index/dex/Iterator.h
@@ -99,7 +99,9 @@
   ///
   /// Where Type is the iterator type representation: "&" for And, "|" for Or,
   /// ChildN is N-th iterator child. Raw iterators over PostingList are
-  /// represented as "[ID1, ID2, ...]" where IDN is N-th PostingList entry.
+  /// represented as "[ID1, ID2, ..., {IDN}, ... END]" where IDN is N-th
+  /// PostingList entry and the element which is pointed to by the PostingList
+  /// iterator is enclosed in {} braces.
   friend llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
                                        const Iterator &Iterator) {
     return Iterator.dump(OS);
Index: clang-tools-extra/clangd/index/dex/Iterator.cpp
===================================================================
--- clang-tools-extra/clangd/index/dex/Iterator.cpp
+++ clang-tools-extra/clangd/index/dex/Iterator.cpp
@@ -49,10 +49,19 @@
   llvm::raw_ostream &dump(llvm::raw_ostream &OS) const override {
     OS << '[';
     auto Separator = "";
-    for (const auto &ID : Documents) {
-      OS << Separator << ID;
+    for (auto It = std::begin(Documents); It != std::end(Documents); ++It) {
+      OS << Separator;
+      if (It == Index)
+        OS << '{' << *It << '}';
+      else
+        OS << *It;
       Separator = ", ";
     }
+    OS << Separator;
+    if (Index == std::end(Documents))
+      OS << "{END}";
+    else
+      OS << "END";
     OS << ']';
     return OS;
   }
Index: clang-tools-extra/unittests/clangd/DexIndexTests.cpp
===================================================================
--- clang-tools-extra/unittests/clangd/DexIndexTests.cpp
+++ clang-tools-extra/unittests/clangd/DexIndexTests.cpp
@@ -231,13 +231,14 @@
   const PostingList L4 = {0, 1, 5};
   const PostingList L5;
 
-  EXPECT_EQ(llvm::to_string(*(create(L0))), "[4, 7, 8, 20, 42, 100]");
+  EXPECT_EQ(llvm::to_string(*(create(L0))), "[{4}, 7, 8, 20, 42, 100, END]");
 
   auto Nested = createAnd(createAnd(create(L1), create(L2)),
                           createOr(create(L3), create(L4), create(L5)));
 
   EXPECT_EQ(llvm::to_string(*Nested),
-            "(& (& [1, 3, 5, 8, 9] [1, 5, 7, 9]) (| [0, 5] [0, 1, 5] []))");
+            "(& (& [{1}, 3, 5, 8, 9, END] [{1}, 5, 7, 9, END]) (| [0, {5}, "
+            "END] [0, {1}, 5, END] [{END}]))");
 }
 
 TEST(DexIndexIterators, Limit) {