re PR c++/64898 (qtgui-4.8.6 build error)

	PR c++/64898
	* mangle.c (write_mangled_name): Fix test for variable template
	instantiation.

From-SVN: r220666

gcc/cp/ChangeLog

 2015-02-12  Jason Merrill  <jason@redhat.com>
 
+	PR c++/64898
+	* mangle.c (write_mangled_name): Fix test for variable template
+	instantiation.
+
 	* decl.c (begin_destructor_body): Condition clobber on
 	-flifetime-dse.
 

gcc/cp/mangle.c

@@ -682,7 +682,8 @@ write_mangled_name (const tree decl, bool top_level)
     }
   else if (VAR_P (decl)
 	   /* Variable template instantiations are mangled.  */
-	   && !(DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl))
+	   && !(DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl)
+		&& variable_template_p (DECL_TI_TEMPLATE (decl)))
 	   /* The names of non-static global variables aren't mangled.  */
 	   && DECL_EXTERNAL_LINKAGE_P (decl)
 	   && (CP_DECL_CONTEXT (decl) == global_namespace

gcc/testsuite/g++.dg/abi/mangle65.C

+// PR c++/64898
+// { dg-final { scan-assembler-not "_Z6foovar" } }
+
+template <class> void f()
+{
+  extern int foovar;
+  foovar = 42;
+}
+
+int main()
+{
+  f<int>();
+}