1 files changed, 21 insertions, 10 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index bc46aae0a6b..c5836746221 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2920,15 +2920,21 @@ void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
 /// definitions here, since the initializer hasn't been attached.
 ///
 void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous,
-                        bool MergeTypeWithPrevious) {
+                        bool IsVariableTemplate, bool MergeTypeWithPrevious) {
   // If the new decl is already invalid, don't do any other checking.
   if (New->isInvalidDecl())
     return;
 
-  // Verify the old decl was also a variable.
+  // Verify the old decl was also a variable or variable template.
   VarDecl *Old = 0;
-  if (!Previous.isSingleResult() ||
-      !(Old = dyn_cast<VarDecl>(Previous.getFoundDecl()))) {
+  if (Previous.isSingleResult() &&
+      (Old = dyn_cast<VarDecl>(Previous.getFoundDecl()))) {
+    if (IsVariableTemplate)
+      Old = Old->getDescribedVarTemplate() ? Old : 0;
+    else
+      Old = Old->getDescribedVarTemplate() ? 0 : Old;
+  }
+  if (!Old) {
     Diag(New->getLocation(), diag::err_redefinition_different_kind)
       << New->getDeclName();
     Diag(Previous.getRepresentativeDecl()->getLocation(),
@@ -4919,6 +4925,7 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
   bool IsExplicitSpecialization = false;
   bool IsVariableTemplateSpecialization = false;
   bool IsPartialSpecialization = false;
+  bool IsVariableTemplate = false;
   bool Invalid = false; // TODO: Can we remove this (error-prone)?
   TemplateParameterList *TemplateParams = 0;
   VarTemplateDecl *PrevVarTemplate = 0;
@@ -5019,6 +5026,7 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
 
         } else { // if (TemplateParams->size() > 0)
           // This is a template declaration.
+          IsVariableTemplate = true;
 
           // Check that we can declare a template here.
           if (CheckTemplateDeclScope(S, TemplateParams))
@@ -5310,9 +5318,11 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
         LookupResult PrevDecl(*this, GetNameForDeclarator(D),
                               LookupOrdinaryName, ForRedeclaration);
         PrevDecl.addDecl(PrevVarTemplate->getTemplatedDecl());
-        D.setRedeclaration(CheckVariableDeclaration(NewVD, PrevDecl));
+        D.setRedeclaration(
+            CheckVariableDeclaration(NewVD, PrevDecl, IsVariableTemplate));
       } else
-        D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
+        D.setRedeclaration(
+            CheckVariableDeclaration(NewVD, Previous, IsVariableTemplate));
     }
 
     // This is an explicit specialization of a static data member. Check it.
@@ -5340,8 +5350,8 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
     }
   }
 
-  // If this is not a variable template, return it now
-  if (!TemplateParams || IsVariableTemplateSpecialization)
+  // If this is not a variable template, return it now.
+  if (!IsVariableTemplate)
     return NewVD;
 
   // If this is supposed to be a variable template, create it as such.
@@ -5745,7 +5755,8 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
 ///
 /// Returns true if the variable declaration is a redeclaration.
 bool Sema::CheckVariableDeclaration(VarDecl *NewVD,
-                                    LookupResult &Previous) {
+                                    LookupResult &Previous,
+                                    bool IsVariableTemplate) {
   CheckVariableDeclarationType(NewVD);
 
   // If the decl is already known invalid, don't check it.
@@ -5795,7 +5806,7 @@ bool Sema::CheckVariableDeclaration(VarDecl *NewVD,
   filterNonConflictingPreviousDecls(Context, NewVD, Previous);
 
   if (!Previous.empty()) {
-    MergeVarDecl(NewVD, Previous, MergeTypeWithPrevious);
+    MergeVarDecl(NewVD, Previous, IsVariableTemplate, MergeTypeWithPrevious);
     return true;
   }
   return false;