re PR c++/9537 ([New parser] problem handling const return types)

        PR c++/9537
        * call.c (conditional_conversion): Build an RVALUE_CONV if
        we're just changing the cv-quals.
        (build_conditional_expr): Don't call convert to change
        cv-quals.

From-SVN: r66502

gcc/cp/ChangeLog

+2003-05-05  Jason Merrill  <jason@redhat.com>
+
+	PR c++/9537
+	* call.c (conditional_conversion): Build an RVALUE_CONV if
+	we're just changing the cv-quals.
+	(build_conditional_expr): Don't call convert to change
+	cv-quals.
+
 2003-05-05  Kriang Lerdsuwanakij  <lerdsuwa@users.sourceforge.net>
 
 	PR c++/10496

gcc/cp/call.c

@@ -3187,7 +3187,10 @@ conditional_conversion (tree e1, tree e2)
      same cv-qualification as, or a greater cv-qualification than, the
      cv-qualification of T1.  If the conversion is applied, E1 is
      changed to an rvalue of type T2 that still refers to the original
-     source class object (or the appropriate subobject thereof).  */
+     source class object (or the appropriate subobject thereof).
+
+     FIXME we can't express an rvalue that refers to the original object;
+     we have to create a new one.  */
   if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
       && same_or_base_type_p (TYPE_MAIN_VARIANT (t2), 
 			      TYPE_MAIN_VARIANT (t1)))
@@ -3197,7 +3200,12 @@ conditional_conversion (tree e1, tree e2)
 	  conv = build1 (IDENTITY_CONV, t1, e1);
 	  if (!same_type_p (TYPE_MAIN_VARIANT (t1), 
 			    TYPE_MAIN_VARIANT (t2)))
-	    conv = build_conv (BASE_CONV, t2, conv);
+	    {
+	      conv = build_conv (BASE_CONV, t2, conv);
+	      NEED_TEMPORARY_P (conv) = 1;
+	    }
+	  else
+	    conv = build_conv (RVALUE_CONV, t2, conv);
 	  return conv;
 	}
       else
@@ -3337,11 +3345,8 @@ build_conditional_expr (tree arg1, tree arg2, tree arg3)
 	{
 	  arg2 = convert_like (conv2, arg2);
 	  arg2 = convert_from_reference (arg2);
-	  /* That may not quite have done the trick.  If the two types
-	     are cv-qualified variants of one another, we will have
-	     just used an IDENTITY_CONV.  */
 	  if (!same_type_p (TREE_TYPE (arg2), arg3_type))
-	    arg2 = convert (arg3_type, arg2);
+	    abort ();
 	  arg2_type = TREE_TYPE (arg2);
 	}
       else if (conv3 && !ICS_BAD_FLAG (conv3))
@@ -3349,7 +3354,7 @@ build_conditional_expr (tree arg1, tree arg2, tree arg3)
 	  arg3 = convert_like (conv3, arg3);
 	  arg3 = convert_from_reference (arg3);
 	  if (!same_type_p (TREE_TYPE (arg3), arg2_type))
-	    arg3 = convert (arg2_type, arg3);
+	    abort ();
 	  arg3_type = TREE_TYPE (arg3);
 	}
     }

gcc/testsuite/g++.dg/conversion/cond3.C

+// PR c++/9537
+
+class String
+{
+public:
+    String();
+    String( char *str );
+    operator char *();
+};
+
+const String operator+( String s1, String )
+{
+  return s1;
+}
+
+String valGlue(const String before)
+{
+    String ret;
+    return false ? ret : before + before;
+}