Weaken restriction in r304862 to allow implicit deduction guides to reference
the injected-class-name of a specialization that uses a partial / explicit
specialization.

llvm-svn: 304957
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 9e8b4d5..148ce24 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -4807,7 +4807,7 @@
 DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
                           const MultiLevelTemplateArgumentList &TemplateArgs) {
   if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
-    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs);
+    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs, true);
     return cast_or_null<DeclContext>(ID);
   } else return DC;
 }
@@ -4839,7 +4839,8 @@
 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
 /// this mapping from within the instantiation of <tt>X<int></tt>.
 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
-                          const MultiLevelTemplateArgumentList &TemplateArgs) {
+                          const MultiLevelTemplateArgumentList &TemplateArgs,
+                          bool FindingInstantiatedContext) {
   DeclContext *ParentDC = D->getDeclContext();
   // FIXME: Parmeters of pointer to functions (y below) that are themselves 
   // parameters (p below) can have their ParentDC set to the translation-unit
@@ -5007,8 +5008,9 @@
           // meaningless to attempt to find an instantiation of D within the
           // specialization.)
           // FIXME: The standard doesn't say what should happen here.
-          if (usesPartialOrExplicitSpecialization(Loc,
-                cast<ClassTemplateSpecializationDecl>(SubstRecord))) {
+          if (FindingInstantiatedContext &&
+              usesPartialOrExplicitSpecialization(
+                  Loc, cast<ClassTemplateSpecializationDecl>(SubstRecord))) {
             Diag(Loc, diag::err_specialization_not_primary_template)
               << T << (SubstRecord->getTemplateSpecializationKind() ==
                            TSK_ExplicitSpecialization);