diff --git a/ChangeLog b/ChangeLog
index 7d1a1b492a..e14357c40f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Sep  3 17:47:58 2004  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* struct.c (make_struct): remove redefining constant when
+	  conflict.  [ruby-dev:24210]
+
 Fri Sep  3 11:31:44 2004  Hidetoshi NAGAI  <nagai@ai.kyutech.ac.jp>
 
 	* ext/tk/lib/tk.rb: Tk.after makes TkCore::INTERP.tk_cmd_tbl grow
diff --git a/bignum.c b/bignum.c
index 5f008544c0..accd14d958 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1752,15 +1752,17 @@ rb_big_or(xx, yy)
  */
 
 VALUE
-rb_big_xor(x, y)
-    VALUE x, y;
+rb_big_xor(xx, yy)
+    VALUE xx, yy;
 {
+    volatile VALUE x, y;
     VALUE z;
     BDIGIT *ds1, *ds2, *zds;
     long i, l1, l2;
     char sign;
 
-    y = rb_to_int(y);
+    x = xx;
+    y = rb_to_int(yy);
     if (FIXNUM_P(y)) {
 	y = rb_int2big(FIX2LONG(y));
     }
diff --git a/eval.c b/eval.c
index 3829be617f..46c687dc4e 100644
--- a/eval.c
+++ b/eval.c
@@ -1717,37 +1717,6 @@ rb_eval_cmd(cmd, arg, level)
     return val;
 }
 
-static VALUE
-superclass(self, node)
-    VALUE self;
-    NODE *node;
-{
-    VALUE val = Qnil;		/* OK */
-    int state;
-
-    PUSH_TAG(PROT_NONE);
-    if ((state = EXEC_TAG()) == 0) {
-	val = rb_eval(self, node);
-    }
-    POP_TAG();
-    if (state) {
-	switch (nd_type(node)) {
-	  case NODE_COLON2:
-	    rb_raise(rb_eTypeError, "undefined superclass `%s'",
-		     rb_id2name(node->nd_mid));
-	  case NODE_CONST:
-	    rb_raise(rb_eTypeError, "undefined superclass `%s'",
-		     rb_id2name(node->nd_vid));
-	  default:
-	    break;
-	}
-	JUMP_TAG(state);
-    }
-    rb_check_inheritable(val);
-
-    return val;
-}
-
 #define ruby_cbase (ruby_cref->nd_clss)
 
 static VALUE
@@ -3772,7 +3741,8 @@ rb_eval(self, n)
 		rb_raise(rb_eTypeError, "no outer class/module");
 	    }
 	    if (node->nd_super) {
-		super = superclass(self, node->nd_super);
+               super = rb_eval(self, node->nd_super);
+               rb_check_inheritable(super);
 	    }
 	    else {
 		super = 0;
diff --git a/math.c b/math.c
index 5b9294e781..cea7bb801d 100644
--- a/math.c
+++ b/math.c
@@ -331,6 +331,28 @@ math_log(obj, x)
     return rb_float_new(d);
 }
 
+/*
+ *  call-seq:
+ *     Math.log2(numeric)    => float
+ *  
+ *  Returns the base 2 logarithm of <i>numeric</i>.
+ */
+
+static VALUE
+math_log2(obj, x)
+    VALUE obj, x;
+{
+    double d;
+
+    Need_Float(x);
+    errno = 0;
+    d = log2(RFLOAT(x)->value);
+    if (errno) {
+	rb_sys_fail("log2");
+    }
+    return rb_float_new(d);
+}
+
 /*
  *  call-seq:
  *     Math.log10(numeric)    => float
@@ -511,6 +533,7 @@ Init_Math()
 
     rb_define_module_function(rb_mMath, "exp", math_exp, 1);
     rb_define_module_function(rb_mMath, "log", math_log, 1);
+    rb_define_module_function(rb_mMath, "log2", math_log, 1);
     rb_define_module_function(rb_mMath, "log10", math_log10, 1);
     rb_define_module_function(rb_mMath, "sqrt", math_sqrt, 1);
 
diff --git a/struct.c b/struct.c
index e629f9827d..b47d647490 100644
--- a/struct.c
+++ b/struct.c
@@ -177,6 +177,10 @@ make_struct(name, member, klass)
 	if (!rb_is_const_id(id)) {
 	    rb_name_error(id, "identifier %s needs to be constant", cname);
 	}
+	if (rb_const_defined_at(klass, id)) {
+	    rb_warn("redefining constant Struct::%s", cname);
+	    rb_mod_remove_const(klass, ID2SYM(id));
+	}
 	nstr = rb_define_class_under(klass, cname, klass);
     }
     rb_iv_set(nstr, "__size__", LONG2NUM(RARRAY(member)->len));
@@ -455,6 +459,10 @@ inspect_struct(s)
     if (NIL_P(member)) {
 	rb_bug("non-initialized struct");
     }
+    if (RSTRUCT(s)->len != RARRAY(member)->len) {
+	rb_raise(rb_eTypeError, "struct size differs (%d required %d given)",
+		 RARRAY(member)->len, RSTRUCT(s)->len);
+    }
 
     str = rb_str_buf_new2("#<struct ");
     rb_str_cat2(str, cname);