Index: libcxxabi/src/demangle/ItaniumDemangle.h
===================================================================
--- libcxxabi/src/demangle/ItaniumDemangle.h
+++ libcxxabi/src/demangle/ItaniumDemangle.h
@@ -2591,7 +2591,7 @@
   Node *parseAbiTags(Node *N);
 
   /// Parse the <unresolved-name> production.
-  Node *parseUnresolvedName();
+  Node *parseUnresolvedName(bool Global);
   Node *parseSimpleId();
   Node *parseBaseUnresolvedName();
   Node *parseUnresolvedType();
@@ -3418,6 +3418,7 @@
 //                   ::= [gs] <base-unresolved-name>                     # x or (with "gs") ::x
 //                   ::= [gs] sr <unresolved-qualifier-level>+ E <base-unresolved-name>
 //                                                                       # A::x, N::y, A<T>::z; "gs" means leading "::"
+// [gs] has been parsed by caller.
 //                   ::= sr <unresolved-type> <base-unresolved-name>     # T::x / decltype(p)::x
 //  extension        ::= sr <unresolved-type> <template-args> <base-unresolved-name>
 //                                                                       # T::N::x /decltype(p)::N::x
@@ -3425,7 +3426,7 @@
 //
 // <unresolved-qualifier-level> ::= <simple-id>
 template <typename Derived, typename Alloc>
-Node *AbstractManglingParser<Derived, Alloc>::parseUnresolvedName() {
+Node *AbstractManglingParser<Derived, Alloc>::parseUnresolvedName(bool Global) {
   Node *SoFar = nullptr;
 
   // srN <unresolved-type> [<template-args>] <unresolved-qualifier-level>* E <base-unresolved-name>
@@ -3459,8 +3460,6 @@
     return make<QualifiedName>(SoFar, Base);
   }
 
-  bool Global = consumeIf("gs");
-
   // [gs] <base-unresolved-name>                     # x or (with "gs") ::x
   if (!consumeIf("sr")) {
     SoFar = getDerived().parseBaseUnresolvedName();
@@ -4727,7 +4726,7 @@
       return make<DeleteExpr>(E, Global, /*is_array=*/false);
     }
     case 'n':
-      return getDerived().parseUnresolvedName();
+      return getDerived().parseUnresolvedName(Global);
     case 's': {
       First += 2;
       Node *LHS = getDerived().parseExpr();
@@ -4899,7 +4898,7 @@
   case 'o':
     switch (First[1]) {
     case 'n':
-      return getDerived().parseUnresolvedName();
+      return getDerived().parseUnresolvedName(Global);
     case 'o':
       First += 2;
       return getDerived().parseBinaryExpr("||");
@@ -5017,7 +5016,7 @@
       return make<ParameterPackExpansion>(Child);
     }
     case 'r':
-      return getDerived().parseUnresolvedName();
+      return getDerived().parseUnresolvedName(Global);
     case 't': {
       First += 2;
       Node *Ty = getDerived().parseType();
@@ -5150,7 +5149,7 @@
   case '7':
   case '8':
   case '9':
-    return getDerived().parseUnresolvedName();
+    return getDerived().parseUnresolvedName(Global);
   }
   return nullptr;
 }
Index: libcxxabi/test/test_demangle.pass.cpp
===================================================================
--- libcxxabi/test/test_demangle.pass.cpp
+++ libcxxabi/test/test_demangle.pass.cpp
@@ -29861,6 +29861,8 @@
     {"_ZN2FnIXgsdlLi4EEXdaLi4EEEEvv", "void Fn<::delete 4, delete[] 4>()"},
     {"_ZN2FnIXdlLj4EEXgsdaLj4EEEEvv", "void Fn<delete 4u, ::delete[] 4u>()"},
 
+    {"_ZN2FnIXgs4BaseEX4BaseEEEvv","void Fn<::Base, Base>()"},
+    
     {"_Z3TPLIiET_S0_", "int TPL<int>(int)"},
 
     // C++20 modules
Index: llvm/include/llvm/Demangle/ItaniumDemangle.h
===================================================================
--- llvm/include/llvm/Demangle/ItaniumDemangle.h
+++ llvm/include/llvm/Demangle/ItaniumDemangle.h
@@ -2591,7 +2591,7 @@
   Node *parseAbiTags(Node *N);
 
   /// Parse the <unresolved-name> production.
-  Node *parseUnresolvedName();
+  Node *parseUnresolvedName(bool Global);
   Node *parseSimpleId();
   Node *parseBaseUnresolvedName();
   Node *parseUnresolvedType();
@@ -3418,6 +3418,7 @@
 //                   ::= [gs] <base-unresolved-name>                     # x or (with "gs") ::x
 //                   ::= [gs] sr <unresolved-qualifier-level>+ E <base-unresolved-name>
 //                                                                       # A::x, N::y, A<T>::z; "gs" means leading "::"
+// [gs] has been parsed by caller.
 //                   ::= sr <unresolved-type> <base-unresolved-name>     # T::x / decltype(p)::x
 //  extension        ::= sr <unresolved-type> <template-args> <base-unresolved-name>
 //                                                                       # T::N::x /decltype(p)::N::x
@@ -3425,7 +3426,7 @@
 //
 // <unresolved-qualifier-level> ::= <simple-id>
 template <typename Derived, typename Alloc>
-Node *AbstractManglingParser<Derived, Alloc>::parseUnresolvedName() {
+Node *AbstractManglingParser<Derived, Alloc>::parseUnresolvedName(bool Global) {
   Node *SoFar = nullptr;
 
   // srN <unresolved-type> [<template-args>] <unresolved-qualifier-level>* E <base-unresolved-name>
@@ -3459,8 +3460,6 @@
     return make<QualifiedName>(SoFar, Base);
   }
 
-  bool Global = consumeIf("gs");
-
   // [gs] <base-unresolved-name>                     # x or (with "gs") ::x
   if (!consumeIf("sr")) {
     SoFar = getDerived().parseBaseUnresolvedName();
@@ -4727,7 +4726,7 @@
       return make<DeleteExpr>(E, Global, /*is_array=*/false);
     }
     case 'n':
-      return getDerived().parseUnresolvedName();
+      return getDerived().parseUnresolvedName(Global);
     case 's': {
       First += 2;
       Node *LHS = getDerived().parseExpr();
@@ -4899,7 +4898,7 @@
   case 'o':
     switch (First[1]) {
     case 'n':
-      return getDerived().parseUnresolvedName();
+      return getDerived().parseUnresolvedName(Global);
     case 'o':
       First += 2;
       return getDerived().parseBinaryExpr("||");
@@ -5017,7 +5016,7 @@
       return make<ParameterPackExpansion>(Child);
     }
     case 'r':
-      return getDerived().parseUnresolvedName();
+      return getDerived().parseUnresolvedName(Global);
     case 't': {
       First += 2;
       Node *Ty = getDerived().parseType();
@@ -5150,7 +5149,7 @@
   case '7':
   case '8':
   case '9':
-    return getDerived().parseUnresolvedName();
+    return getDerived().parseUnresolvedName(Global);
   }
   return nullptr;
 }