From 83bd6584eee4877c8d8c014f9c6342e01f6eb118 Mon Sep 17 00:00:00 2001
From: Robin Sommer <robin@icir.org>
Date: Tue, 8 Mar 2011 16:27:07 -0800
Subject: [PATCH] Enabling record coercion for a table's &default attribute.

---
 src/Attr.cc | 10 ++++++++++
 src/Val.cc  | 17 ++++++++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/Attr.cc b/src/Attr.cc
index e03367c41e..98be9a9465 100644
--- a/src/Attr.cc
+++ b/src/Attr.cc
@@ -219,7 +219,17 @@ void Attributes::CheckAttr(Attr* a)
 					Error("&default function type clash");
 				}
 			else
+				{
+				BroType* ytype = tt->YieldType();
+
+				// Table defaults may be promotable.
+				if ( atype->Tag() == TYPE_RECORD && ytype->Tag() == TYPE_RECORD &&
+					 record_promotion_compatible(atype->AsRecordType(), ytype->AsRecordType()) )
+					 // Ok.
+					 break;
+
 				Error("&default value has inconsistent type");
+				}
 			}
 		}
 		break;
diff --git a/src/Val.cc b/src/Val.cc
index ba1cda41e7..a665249539 100644
--- a/src/Val.cc
+++ b/src/Val.cc
@@ -2023,7 +2023,22 @@ Val* TableVal::Default(Val* index)
 		return 0;
 
 	if ( ! def_val )
-		def_val = def_attr->AttrExpr()->Eval(0);
+		{
+		BroType* ytype = Type()->YieldType();
+		BroType* dtype = def_attr->AttrExpr()->Type();
+
+		if ( dtype->Tag() == TYPE_RECORD && ytype->Tag() == TYPE_RECORD &&
+			! same_type(dtype, ytype) &&
+			record_promotion_compatible(dtype->AsRecordType(), ytype->AsRecordType()) )
+			{
+			Expr* coerce = new RecordCoerceExpr(def_attr->AttrExpr(), ytype->AsRecordType());
+			def_val = coerce->Eval(0);
+			Unref(coerce);
+			}
+
+		else
+			def_val = def_attr->AttrExpr()->Eval(0);
+		}
 
 	if ( ! def_val )
 		{