diff --git a/ChangeLog b/ChangeLog
index 9291152759..fb7026e155 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,10 +1,43 @@
+Thu Jul  3 14:22:46 2003  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* array.c (rb_values_at): extract common procedure from
+	  rb_ary_values_at.  follow DRY principle.
+
+	* re.c (match_values_at): values_at should understand ranges.
+
+	* struct.c (rb_struct_values_at): ditto.
+
+	* struct.c (inspect_struct): inspect format changed; add "struct "
+	  at the top.
+
+	* sprintf.c (rb_f_sprintf): "%p" specifier for inspect output.
+	  (RCR#68)
+
+	* eval.c (rb_mod_undef_method): allow "undef_method" to accept
+	  multiple arguments. (RCR#146)
+
+	* lib/timeout.rb: put timeout in Timeout module. (RCR#121)
+	  [ruby-talk:61028]
+
+	* re.c (match_groups): new method added. (RCR#139)
+
+	* variable.c (rb_mod_const_of): should exclude constant defined
+	  in Object, unless retrieving constants of Object.
+
 Thu Jul  3 12:13:05 2003  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* lib/mkmf.rb (VPATH): convert from Windows form to Unix form on 
 	  MinGW.  This fixes the build with GNU make 3.80-1 for Cygwin.
 
+Wed Jul  2 23:27:34 2003  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* string.c (rb_str_new4): do not allocate new string if original
+	  is frozen or already have copy-on-write entry. [ruby-talk:74940]
+
 Wed Jul  2 13:22:39 2003  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
+	* string.c (rb_str_new4): 
+
 	* string.c (rb_str_shared_replace): clear flags before copy.
 
 	* string.c (rb_str_replace): ditto.
diff --git a/array.c b/array.c
index 69bf714e6f..3687772fc3 100644
--- a/array.c
+++ b/array.c
@@ -1218,29 +1218,37 @@ rb_ary_collect_bang(ary)
     return ary;
 }
 
-static void
-push_values_at(result, ary, arg)
-    VALUE result, ary, arg;
+VALUE
+rb_values_at(obj, olen, argc, argv, func)
+    VALUE obj;
+    long olen;
+    int argc;
+    VALUE *argv;
+    VALUE (*func) _((VALUE,long));
 {
-    long beg, len, i;
+    VALUE result = rb_ary_new2(argc);
+    long beg, len, i, j;
 
-    if (FIXNUM_P(arg)) {
-	rb_ary_push(result, rb_ary_entry(ary, FIX2LONG(arg)));
-	return;
-    }
-    /* check if idx is Range */
-    switch (rb_range_beg_len(arg, &beg, &len, RARRAY(ary)->len, 0)) {
-      case Qfalse:
-	break;
-      case Qnil:
-	return;
-      default:
-	for (i=0; i<len; i++) {
-	    rb_ary_push(result, rb_ary_entry(ary, i+beg));
+    for (i=0; i<argc; i++) {
+	if (FIXNUM_P(argv[i])) {
+	    rb_ary_push(result, (*func)(obj, FIX2LONG(argv[i])));
+	    continue;
 	}
-	return;
+	/* check if idx is Range */
+	switch (rb_range_beg_len(argv[i], &beg, &len, olen, 0)) {
+	  case Qfalse:
+	    break;
+	  case Qnil:
+	    continue;
+	  default:
+	    for (j=0; j<len; j++) {
+		rb_ary_push(result, (*func)(obj, j+beg));
+	    }
+	    continue;
+	}
+	rb_ary_push(result, (*func)(obj, NUM2LONG(argv[i])));
     }
-    rb_ary_push(result, rb_ary_entry(ary, NUM2LONG(arg)));
+    return result;
 }
 
 static VALUE
@@ -1249,13 +1257,7 @@ rb_ary_values_at(argc, argv, ary)
     VALUE *argv;
     VALUE ary;
 {
-    VALUE result = rb_ary_new2(argc);
-    long i;
-
-    for (i=0; i<argc; i++) {
-	push_values_at(result, ary, argv[i]);
-    }
-    return result;
+    return rb_values_at(ary, RARRAY(ary)->len, argc, argv, rb_ary_entry);
 }
 
 static VALUE
diff --git a/eval.c b/eval.c
index 186e23db95..f560d3a185 100644
--- a/eval.c
+++ b/eval.c
@@ -362,6 +362,7 @@ rb_get_method_body(klassp, idp, noexp)
 	    body = ent->method = body->nd_head;
 	}
 	else {
+	    if (BUILTIN_TYPE(origin) == T_ICLASS) origin = RBASIC(origin)->klass;
 	    *klassp = origin;
 	    ent->origin = origin;
 	    ent->mid = ent->mid0 = id;
@@ -1824,10 +1825,16 @@ rb_undef(klass, id)
 }
 
 static VALUE
-rb_mod_undef_method(mod, name)
-    VALUE mod, name;
+rb_mod_undef_method(argc, argv, mod)
+    int argc;
+    VALUE *argv;
+    VALUE mod;
 {
-    rb_undef(mod, rb_to_id(name));
+    int i;
+
+    for (i=0; i<argc; i++) {
+	rb_undef(mod, rb_to_id(argv[i]));
+    }
     return mod;
 }
 
@@ -6521,7 +6528,7 @@ Init_eval()
     rb_undef_method(rb_cClass, "module_function");
 
     rb_define_private_method(rb_cModule, "remove_method", rb_mod_remove_method, 1);
-    rb_define_private_method(rb_cModule, "undef_method", rb_mod_undef_method, 1);
+    rb_define_private_method(rb_cModule, "undef_method", rb_mod_undef_method, -1);
     rb_define_private_method(rb_cModule, "alias_method", rb_mod_alias_method, 2);
     rb_define_private_method(rb_cModule, "define_method", rb_mod_define_method, -1);
 
diff --git a/intern.h b/intern.h
index f80e5de217..e31e883f15 100644
--- a/intern.h
+++ b/intern.h
@@ -56,6 +56,7 @@ VALUE rb_ary_cmp _((VALUE, VALUE));
 VALUE rb_protect_inspect _((VALUE(*)(ANYARGS),VALUE,VALUE));
 VALUE rb_inspecting_p _((VALUE));
 VALUE rb_check_array_value _((VALUE));
+VALUE rb_values_at _((VALUE, long, int, VALUE*, VALUE(*) _((VALUE,long))));
 /* bignum.c */
 VALUE rb_big_clone _((VALUE));
 void rb_big_2comp _((VALUE));
diff --git a/lib/debug.rb b/lib/debug.rb
index 0caeecb00c..9275b47cd9 100644
--- a/lib/debug.rb
+++ b/lib/debug.rb
@@ -700,9 +700,11 @@ EOHELP
     @line = line
     case event
     when 'line'
+      p [line, @stop_next]
       frame_set_pos(file, line)
       if !@no_step or @frames.size == @no_step
 	@stop_next -= 1
+	@stop_next = 0 if @stop_next < 0
       elsif @frames.size < @no_step
 	@stop_next = 0		# break here before leaving...
       else
diff --git a/lib/irb/context.rb b/lib/irb/context.rb
index 9022e8138c..f1194f8db9 100644
--- a/lib/irb/context.rb
+++ b/lib/irb/context.rb
@@ -177,6 +177,7 @@ module IRB
       @inspect_mode
     end
 
+    undef use_readline=
     def use_readline=(opt)
       @use_readline = opt
       print "use readline module\n" if @use_readline
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 7ae2349046..9b01d67c4c 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -8,6 +8,7 @@ CONFIG = Config::MAKEFILE_CONFIG
 ORIG_LIBPATH = ENV['LIB']
 
 SRC_EXT = ["c", "cc", "m", "cxx", "cpp", "C"]
+$static = $config_h = nil
 
 unless defined? $configure_args
   $configure_args = {}
diff --git a/lib/timeout.rb b/lib/timeout.rb
index 8c6ccb7128..00e60aff8c 100644
--- a/lib/timeout.rb
+++ b/lib/timeout.rb
@@ -23,25 +23,38 @@
 #
 #    The time in seconds to wait for block teminatation.   
 #
+#  : [exception]
+#
+#    The exception classs to be raised on timeout.
+#
 #=end
 
-class TimeoutError<Interrupt
+module Timeout
+  class Error<Interrupt
+  end
+
+  def timeout(sec, exception=Error)
+    return yield if sec == nil
+    begin
+      x = Thread.current
+      y = Thread.start {
+        sleep sec
+        x.raise exception, "execution expired" if x.alive?
+      }
+      yield sec
+      #    return true
+    ensure
+      y.kill if y and y.alive?
+    end
+  end
+  module_function :timeout
 end
 
-def timeout(sec, exception=TimeoutError)
-  return yield if sec == nil
-  begin
-    x = Thread.current
-    y = Thread.start {
-      sleep sec
-      x.raise exception, "execution expired" if x.alive?
-    }
-    yield sec
-#    return true
-  ensure
-    y.kill if y and y.alive?
-  end
+# compatible
+def timeout(n, &block)
+  Timeout::timeout(n, &block)
 end
+TimeoutError = Timeout::Error
 
 if __FILE__ == $0
   p timeout(5) {
diff --git a/re.c b/re.c
index dd1800027a..313486c22e 100644
--- a/re.c
+++ b/re.c
@@ -914,8 +914,9 @@ last_paren_match_getter()
 }
 
 static VALUE
-match_to_a(match)
+match_array(match, start)
     VALUE match;
+    int start;
 {
     struct re_registers *regs = RMATCH(match)->regs;
     VALUE ary = rb_ary_new2(regs->num_regs);
@@ -923,7 +924,7 @@ match_to_a(match)
     int i;
     int taint = OBJ_TAINTED(match);
     
-    for (i=0; i<regs->num_regs; i++) {
+    for (i=start; i<regs->num_regs; i++) {
 	if (regs->beg[i] == -1) {
 	    rb_ary_push(ary, Qnil);
 	}
@@ -936,6 +937,20 @@ match_to_a(match)
     return ary;
 }
 
+static VALUE
+match_to_a(match)
+    VALUE match;
+{
+    return match_array(match, 0);
+}
+
+static VALUE
+match_groups(match)
+    VALUE match;
+{
+    return match_array(match, 1);
+}
+
 static VALUE
 match_aref(argc, argv, match)
     int argc;
@@ -952,32 +967,21 @@ match_aref(argc, argv, match)
     return rb_reg_nth_match(FIX2INT(idx), match);
 }
 
+static VALUE
+match_entry(match, n)
+    VALUE match;
+    long n;
+{
+    return rb_reg_nth_match(n, match);
+}
+
 static VALUE
 match_values_at(argc, argv, match)
     int argc;
     VALUE *argv;
     VALUE match;
 {
-    struct re_registers *regs = RMATCH(match)->regs;
-    VALUE target = RMATCH(match)->str;
-    VALUE result = rb_ary_new();
-    int i;
-    long idx;
-    int taint = OBJ_TAINTED(match);
-
-    for (i=0; i<argc; i++) {
-	idx = NUM2LONG(argv[i]);
-	if (idx < 0) idx += regs->num_regs;
-	if (idx < 0 || regs->num_regs <= idx) {
-	    rb_ary_push(result, Qnil);
-	}
-	else {
-	    VALUE str = rb_str_substr(target, regs->beg[idx], regs->end[idx]-regs->beg[idx]);
-	    if (taint) OBJ_TAINT(str);
-	    rb_ary_push(result, str);
-	}
-    }
-    return result;
+    return rb_values_at(match, RMATCH(match)->regs->num_regs, argc, argv, match_entry);
 }
 
 static VALUE
@@ -1766,6 +1770,7 @@ Init_Regexp()
     rb_define_method(rb_cMatch, "end", match_end, 1);
     rb_define_method(rb_cMatch, "to_a", match_to_a, 0);
     rb_define_method(rb_cMatch, "[]", match_aref, -1);
+    rb_define_method(rb_cMatch, "groups", match_groups, 0);
     rb_define_method(rb_cMatch, "select", match_select, -1);
     rb_define_method(rb_cMatch, "values_at", match_values_at, -1);
     rb_define_method(rb_cMatch, "pre_match", rb_reg_match_pre, 0);
diff --git a/sprintf.c b/sprintf.c
index b89f441708..70bd270f2b 100644
--- a/sprintf.c
+++ b/sprintf.c
@@ -291,10 +291,12 @@ rb_f_sprintf(argc, argv)
 	    break;
 
 	  case 's':
+	  case 'p':
 	    {
 		VALUE arg = GETARG();
 		long len;
 
+		if (*p == 'p') arg = rb_inspect(arg);
 		str = rb_obj_as_string(arg);
 		if (OBJ_TAINTED(str)) tainted = 1;
 		len = RSTRING(str)->len;
diff --git a/string.c b/string.c
index 25b325f0ec..692a158c09 100644
--- a/string.c
+++ b/string.c
@@ -157,14 +157,17 @@ rb_str_new4(orig)
 {
     VALUE klass, str;
 
+    if (OBJ_FROZEN(orig)) return orig;
     klass = rb_obj_class(orig);
     if (FL_TEST(orig, ELTS_SHARED) && RSTRING(orig)->aux.shared) {
 	long ofs;
 	str = RSTRING(orig)->aux.shared;
 	ofs = RSTRING(str)->len - RSTRING(orig)->len;
-	str = str_new3(klass, str);
-	RSTRING(str)->ptr += ofs;
-	RSTRING(str)->len -= ofs;
+	if (ofs > 0) {
+	    str = str_new3(klass, str);
+	    RSTRING(str)->ptr += ofs;
+	    RSTRING(str)->len -= ofs;
+	}
     }
     else if (FL_TEST(orig, STR_ASSOC)) {
 	str = str_new(klass, RSTRING(orig)->ptr, RSTRING(orig)->len);
diff --git a/struct.c b/struct.c
index 6d9c8113a9..32ea8f525c 100644
--- a/struct.c
+++ b/struct.c
@@ -351,18 +351,6 @@ rb_struct_each_pair(s)
     return s;
 }
 
-static VALUE
-rb_struct_to_s(s)
-    VALUE s;
-{
-    char *cname = rb_class2name(rb_obj_class(s));
-    VALUE str = rb_str_new(0, strlen(cname) + 4);
-
-    sprintf(RSTRING(str)->ptr, "#<%s>", cname);
-    RSTRING(str)->len = strlen(RSTRING(str)->ptr);
-    return str;
-}
-
 static VALUE
 inspect_struct(s)
     VALUE s;
@@ -376,7 +364,7 @@ inspect_struct(s)
 	rb_bug("non-initialized struct");
     }
 
-    str = rb_str_buf_new2("#<");
+    str = rb_str_buf_new2("#<struct ");
     rb_str_cat2(str, cname);
     rb_str_cat2(str, " ");
     for (i=0; i<RSTRUCT(s)->len; i++) {
@@ -405,9 +393,9 @@ rb_struct_inspect(s)
 {
     if (rb_inspecting_p(s)) {
 	char *cname = rb_class2name(rb_obj_class(s));
-	VALUE str = rb_str_new(0, strlen(cname) + 8);
+	VALUE str = rb_str_new(0, strlen(cname) + 15);
 
-	sprintf(RSTRING(str)->ptr, "#<%s:...>", cname);
+	sprintf(RSTRING(str)->ptr, "#<struct %s:...>", cname);
 	RSTRING(str)->len = strlen(RSTRING(str)->ptr);
 	return str;
     }
@@ -529,20 +517,21 @@ rb_struct_aset(s, idx, val)
     return RSTRUCT(s)->ptr[i] = val;
 }
 
+static VALUE
+struct_entry(s, n)
+    VALUE s;
+    long n;
+{
+    return rb_struct_aref(s, LONG2NUM(n));
+}
+
 static VALUE
 rb_struct_values_at(argc, argv, s)
     int argc;
     VALUE *argv;
     VALUE s;
 {
-    VALUE result = rb_ary_new();
-    long i;
-
-    for (i=0; i<argc; i++) {
-	rb_ary_push(result, rb_struct_aref(s, argv[i]));
-    }
-
-    return result;
+    return rb_values_at(s, RSTRUCT(s)->len, argc, argv, struct_entry);
 }
 
 static VALUE
@@ -648,7 +637,7 @@ Init_Struct()
     rb_define_method(rb_cStruct, "eql?", rb_struct_eql, 1);
     rb_define_method(rb_cStruct, "hash", rb_struct_hash, 0);
 
-    rb_define_method(rb_cStruct, "to_s", rb_struct_to_s, 0);
+    rb_define_method(rb_cStruct, "to_s", rb_struct_inspect, 0);
     rb_define_method(rb_cStruct, "inspect", rb_struct_inspect, 0);
     rb_define_method(rb_cStruct, "to_a", rb_struct_to_a, 0);
     rb_define_method(rb_cStruct, "values", rb_struct_to_a, 0);
diff --git a/variable.c b/variable.c
index fcbc8cc745..8b62aad92a 100644
--- a/variable.c
+++ b/variable.c
@@ -1387,10 +1387,12 @@ rb_mod_const_of(mod, data)
     VALUE mod;
     void *data;
 {
+    VALUE tmp = mod;
     for (;;) {
-	data = rb_mod_const_at(mod, data);
-	mod = RCLASS(mod)->super;
-	if (!mod) break;
+	data = rb_mod_const_at(tmp, data);
+	tmp = RCLASS(tmp)->super;
+	if (!tmp) break;
+	if (tmp == rb_cObject && mod != rb_cObject) break;
     }
     return data;
 }