diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 1dd91a12f17..4b2f677a290 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2004-12-14  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/18793
+	* cp-objcp-common.c (cp_expr_size): Loosen assertion.
+
 2004-12-14  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/18949
diff --git a/gcc/cp/cp-objcp-common.c b/gcc/cp/cp-objcp-common.c
index 9938b98f535..d43c159c01f 100644
--- a/gcc/cp/cp-objcp-common.c
+++ b/gcc/cp/cp-objcp-common.c
@@ -75,21 +75,36 @@ cxx_warn_unused_global_decl (tree decl)
 tree
 cp_expr_size (tree exp)
 {
-  if (CLASS_TYPE_P (TREE_TYPE (exp)))
+  tree type = TREE_TYPE (exp);
+
+  if (CLASS_TYPE_P (type))
     {
       /* The backend should not be interested in the size of an expression
 	 of a type with both of these set; all copies of such types must go
 	 through a constructor or assignment op.  */
-      gcc_assert (!TYPE_HAS_COMPLEX_INIT_REF (TREE_TYPE (exp))
-		  || !TYPE_HAS_COMPLEX_ASSIGN_REF (TREE_TYPE (exp))
+      gcc_assert (!TYPE_HAS_COMPLEX_INIT_REF (type)
+		  || !TYPE_HAS_COMPLEX_ASSIGN_REF (type)
 		  /* But storing a CONSTRUCTOR isn't a copy.  */
-		  || TREE_CODE (exp) == CONSTRUCTOR);
+		  || TREE_CODE (exp) == CONSTRUCTOR
+		  /* And, the gimplifier will sometimes make a copy of
+		     an aggregate.  In particular, for a case like:
+
+		        struct S { S(); };
+                        struct X { int a; S s; };
+                        X x = { 0 };
+
+                     the gimplifier will create a temporary with
+                     static storage duration, perform static
+                     initialization of the temporary, and then copy
+                     the result.  Since the "s" subobject is never
+                     constructed, this is a valid transformation.  */
+		  || CP_AGGREGATE_TYPE_P (type));
       
       /* This would be wrong for a type with virtual bases, but they are
 	 caught by the assert above.  */
-      return (is_empty_class (TREE_TYPE (exp))
+      return (is_empty_class (type)
 	      ? size_zero_node
-	      : CLASSTYPE_SIZE_UNIT (TREE_TYPE (exp)));
+	      : CLASSTYPE_SIZE_UNIT (type));
     }
   else
     /* Use the default code.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 28cd86c9452..b92d0a5d0ab 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2004-12-14  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/18793
+	* g++.dg/init/aggr3.C: New test.
+
 2004-12-14  Janis Johnson  <janis187@us.ibm.com
 
 	* gcc.dg/altivec-types-1.c: New test.
diff --git a/gcc/testsuite/g++.dg/init/aggr3.C b/gcc/testsuite/g++.dg/init/aggr3.C
new file mode 100644
index 00000000000..3376897e105
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/aggr3.C
@@ -0,0 +1,16 @@
+// PR c++/18793
+
+struct S { 
+  S(); 
+  S(const S&); 
+  void operator=(const S&); 
+}; 
+ 
+struct X { 
+  int a, b, c, d, e; 
+  S s; 
+}; 
+ 
+void foobar () { 
+  X x = {0}; 
+}