re PR c++/43076 (ICE: SIGSEGV with invalid C++ code after giving diagnostics)

	PR c++/43076
	* pt.c (push_template_decl_real): Deal better with running out of
	scopes before running out of template parms.

From-SVN: r157842

gcc/cp/ChangeLog

 2010-03-30  Jason Merrill  <jason@redhat.com>
 
+	PR c++/43076
+	* pt.c (push_template_decl_real): Deal better with running out of
+	scopes before running out of template parms.
+
 	PR c++/41185
 	PR c++/41786
 	* parser.c (cp_parser_direct_declarator): Don't allow VLAs in

gcc/cp/pt.c

@@ -4548,6 +4548,9 @@ push_template_decl_real (tree decl, bool is_friend)
 
 	    if (current == decl)
 	      current = ctx;
+	    else if (current == NULL_TREE)
+	      /* Can happen in erroneous input.  */
+	      break;
 	    else
 	      current = (TYPE_P (current)
 			 ? TYPE_CONTEXT (current)

gcc/testsuite/ChangeLog

 2010-03-30  Jason Merrill  <jason@redhat.com>
 
+	PR c++/43076
+	* g++.dg/template/error-recovery1.C: New.
+
 	PR c++/41786
 	* g++.dg/parse/ambig5.C: New.
 

gcc/testsuite/g++.dg/template/error-recovery1.C

+// PR c++/43076
+
+struct S;
+template < typename > struct T
+{
+  template < typename >
+  template < bool > struct T < S > // { dg-error "" }
+  {
+    void f () {			// { dg-error "" }