* array.c (rb_ary_modify): should copy the internal buffer if the

  modifying buffer is shared.

* array.c (ary_make_shared): make an internal buffer of an array
  to be shared.

* array.c (rb_ary_shift): avoid sliding an internal buffer by
  using shared buffer.

* array.c (rb_ary_subseq): avoid copying the buffer.

* parse.y (gettable): should freeze __LINE__ string.

* io.c (rb_io_puts): old behavoir restored.  rationale: a) if you
  want to call to_s for arrays, you can just call print a, "\n".
  b) to_s wastes memory if array (and sum of its contents) is
  huge.  c) now any object that has to_ary is treated as an array,
  using rb_check_convert_type().

* hash.c (rb_hash_initialize): now accepts a block to calculate
  the default value. [new]

* hash.c (rb_hash_aref): call "default" method to get the value
  corrensponding to the non existing key.

* hash.c (rb_hash_default): get the default value based on the
  block given to 'new'.  Now it takes an optinal "key" argument.
  "default" became the method to get the value for non existing
  key.  Users may override "default" method to change the hash
  behavior.

* hash.c (rb_hash_set_default): clear the flag if a block is given
  to 'new'

* object.c (Init_Object): undef Data.allocate, left Data.new.

* ext/curses/curses.c (window_scrollok): use RTEST().

* ext/curses/curses.c (window_idlok): ditto.

* ext/curses/curses.c (window_keypad): ditto.

* ext/curses/curses.c (window_idlok): idlok() may return void on
  some platforms; so don't use return value.

* ext/curses/curses.c (window_scrollok): ditto for consistency.

* ext/curses/curses.c: replace FIX2INT() by typechecking NUM2INT().

* parse.y (str_extend): should not process immature #$x and
  #@x interpolation, e.g #@#@ etc.

* enum.c (enum_sort_by): sort_by does not have to be stable always.

* enum.c (enum_sort_by): call qsort directly to gain performance.

* util.c (ruby_qsort): ruby_qsort(qs6) is now native thread safe.

* error.c (rb_sys_fail): it must be a bug if it's called when
  errno == 0.

* regex.c (WC2MBC1ST): should not pass through > 0x80 number in UTF-8.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@1896 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

19 files changed, 653 insertions, 336 deletions

diff --git a/ChangeLog b/ChangeLog
index 64664b74c8..ed890318a9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,15 +1,53 @@
-Sun Dec  9 23:00:54 2001  Keiju Ishitsuka <keiju@ishitsuka.com>
-	* matrix.rb: Vector#* bug. reported from Massimiliano Mirra
-	<info@chromatic-harp.com>. 
-	
-Sun Dec  9 22:15:59 2001  Nobuyoshi Nakada  <nobu.nakada@nifty.ne.jp>
+Mon Dec 10 02:09:28 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
-	* enum.c (enum_sort_by): should replace with last elements.
+	* array.c (rb_ary_modify): should copy the internal buffer if the
+	  modifying buffer is shared.
+
+	* array.c (ary_make_shared): make an internal buffer of an array
+	  to be shared.
+
+	* array.c (rb_ary_shift): avoid sliding an internal buffer by
+	  using shared buffer.
+
+	* array.c (rb_ary_subseq): avoid copying the buffer.
+
+Mon Dec 10 01:06:56 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* parse.y (gettable): should freeze __LINE__ string.
 
 Sun Dec  9 18:06:26 2001  Minero Aoki  <aamine@loveruby.net>
 
 	* lib/net/protocol.rb: calls on_connect before conn_command
 
+Sat Dec  8 23:27:44 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* io.c (rb_io_puts): old behavoir restored.  rationale: a) if you
+	  want to call to_s for arrays, you can just call print a, "\n".
+	  b) to_s wastes memory if array (and sum of its contents) is
+	  huge.  c) now any object that has to_ary is treated as an array,
+	  using rb_check_convert_type().
+
+Sat Dec  8 22:40:38 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* hash.c (rb_hash_initialize): now accepts a block to calculate
+	  the default value. [new]
+
+	* hash.c (rb_hash_aref): call "default" method to get the value
+	  corrensponding to the non existing key.  
+
+	* hash.c (rb_hash_default): get the default value based on the
+	  block given to 'new'.  Now it takes an optinal "key" argument.
+	  "default" became the method to get the value for non existing
+	  key.  Users may override "default" method to change the hash
+	  behavior.
+
+	* hash.c (rb_hash_set_default): clear the flag if a block is given
+	  to 'new'
+
+Sat Dec  8 02:29:54 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* object.c (Init_Object): undef Data.allocate, left Data.new.
+
 Fri Dec  7 19:12:14 2001  Minero Aoki  <aamine@loveruby.net>
 
 	* lib/net/smtp.rb: SMTP.new requires at least one arg.
@@ -27,12 +65,83 @@ Fri Dec  7 15:49:39 2001  Usaku Nakamura <usa@ruby-lang.org>
 	* ext/extmk.rb.in: ignore adding -Wl,-R to DLDFLAGS when the directory
 	  is $topdir.
 
+Fri Dec  7 13:58:58 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* ext/curses/curses.c (window_scrollok): use RTEST().
+
+	* ext/curses/curses.c (window_idlok): ditto.
+
+	* ext/curses/curses.c (window_keypad): ditto.
+
+	* ext/curses/curses.c (window_idlok): idlok() may return void on
+	  some platforms; so don't use return value.
+
+	* ext/curses/curses.c (window_scrollok): ditto for consistency.
+
+	* ext/curses/curses.c: replace FIX2INT() by typechecking NUM2INT().
+
+Fri Dec  7 09:51:00 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* parse.y (str_extend): should not process immature #$x and
+	  #@x interpolation, e.g #@#@ etc.
+
+Fri Dec  7 03:21:18 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* enum.c (enum_sort_by): sort_by does not have to be stable always.
+
+	* enum.c (enum_sort_by): call qsort directly to gain performance.
+
 Thu Dec  6 18:52:28 2001  Usaku Nakamura  <usa@ruby-lang.org>
 
 	* ext/extmk.rb.in: add -Wl,-R flags to DLDFLAGS on netbsdelf.
 
 	* lib/mkmf.rb: ditto.
 
+Thu Dec  6 09:15:14 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* util.c (ruby_qsort): ruby_qsort(qs6) is now native thread safe.
+
+	* error.c (rb_sys_fail): it must be a bug if it's called when
+	  errno == 0.
+
+Wed Dec  5 23:36:56 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* regex.c (WC2MBC1ST): should not pass through > 0x80 number in UTF-8.
+
+Tue Dec  4 17:43:10 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* ruby.h (DUPSETUP): new SETUP macro for duplication.
+
+	* time.c (time_dup): implement in Time class using DUPSETUP.
+
+	* time.c (time_getlocaltime): new method;  probably requires
+	  better name than getlocaltime. [new,experimental]
+
+	* time.c (time_getgmtime): ditto.
+
+	* array.c (rb_ary_dup): uses DUPSETUP.
+
+	* string.c (rb_str_dup): uses DUPSETUP.  now properly copies
+	  instance variables too.
+
+Tue Dec  4 03:49:06 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* io.c (io_fread): EAGAIN/EWOULDBLOCK should not terminate and
+	  throw away the input.
+
+	* time.c (time_new_internal): underflow adjustment must not use
+	  negative div/mod.
+
+	* time.c (time_cmp): should consider tv_usec on non Fixnum number
+	  comparison.
+Sun Dec  9 23:00:54 2001  Keiju Ishitsuka <keiju@ishitsuka.com>
+	* matrix.rb: Vector#* bug. reported from Massimiliano Mirra
+	<info@chromatic-harp.com>. 
+	
+Sun Dec  9 22:15:59 2001  Nobuyoshi Nakada  <nobu.nakada@nifty.ne.jp>
+
+	* enum.c (enum_sort_by): should replace with last elements.
+
 Mon Dec  3 16:06:57 2001  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* ext/socket/extconf.rb: remove -L/usr/local/lib.
@@ -43,6 +152,13 @@ Mon Dec  3 16:04:16 2001  Usaku Nakamura <usa@ruby-lang.org>
 
 	* configure.in: not use X11BASE, since it's not always set.
 
+Mon Dec  3 13:53:49 2001  Tanaka Akira  <akr@m17n.org>
+
+	* time.c (rb_strftime): buffer length condition was wrong.
+
+	* time.c (time_strftime): should backup buf to the original
+	  buffer.
+
 Mon Dec  3 09:59:08 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* time.c (time_plus): must detect result overflow.
diff --git a/ToDo b/ToDo
index b43679b8a1..4c826c0528 100644
--- a/ToDo
+++ b/ToDo
@@ -71,9 +71,11 @@ Standard Libraries
 - fork_and_kill_other_threads.
 - signal list (Signal::trap, Signal::list).
 - move NameError under StandardError.
+- Integer#to_s(base)
+- Hash::new{default}
+- hash etc. should handle self referenceing array/hash
 * String#scanf(?)
 * Object#fmt(?)
-* Integer#{bin,oct,hex,heX}
 * Time::strptime
 * Integer[num], Float[num];  Fixnum[num]?
 * method to retrieve non-number trailer for to_i/to_f.
@@ -86,16 +88,16 @@ Standard Libraries
 * Array#&, Array#| to allow duplication. ???
 * way to specify immortal (fork endurance) thread;
 * or raise ForkException to every thread but fork caller.
-* Hash::new{default} or recommend Hash#fetch?
 * new user-defined marshal scheme. _dump(dumper), _load(restorer)
-* hash etc. should handle self referenceing array/hash
 * library to load per-user profile seeking .ruby_profile or ruby.ini file.
 * warning framework (warn, warning for Ruby level)
-* marshal should not depend on sprintf/strtod (works bad for locale).
+* marshal should not depend on sprintf/strtod (works bad with locale).
 * ternary arg pow: a.pow(b,c) == a**b%c
 * new caller(), e.g. call_stack; needs better name.
 * remove dependency on MAXPATHLEN.
 * pointer share mechanism similar to one in String for Array.
+* Array#select(n1,n2...) works like Array#indexes(n1,n2...)
+* deprecate Array#indexes, and Array#indices.
 
 Extension Libraries
 
diff --git a/array.c b/array.c
index 6a419d800e..0401dd3598 100644
--- a/array.c
+++ b/array.c
@@ -17,7 +17,7 @@
 #include "st.h"
 
 VALUE rb_cArray;
-static ID cmp;
+static ID id_cmp;
 
 #define ARY_DEFAULT_SIZE 16
 
@@ -45,7 +45,7 @@ memfill(mem, size, val)
 #define ARY_TMPLOCK  FL_USER1
 
 static void
-rb_ary_modify(ary)
+rb_ary_modify_check(ary)
     VALUE ary;
 {
     if (OBJ_FROZEN(ary)) rb_error_frozen("array");
@@ -55,6 +55,21 @@ rb_ary_modify(ary)
 	rb_raise(rb_eSecurityError, "Insecure: can't modify array");
 }
 
+static void
+rb_ary_modify(ary)
+    VALUE ary;
+{
+    VALUE *ptr;
+
+    rb_ary_modify_check(ary);
+    if (!FL_TEST(ary, ELTS_SHARED)) return;
+    ptr = ALLOC_N(VALUE, RARRAY(ary)->len);
+    FL_UNSET(ary, ELTS_SHARED);
+    RARRAY(ary)->aux.capa = RARRAY(ary)->len;
+    MEMCPY(ptr, RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
+    RARRAY(ary)->ptr = ptr;
+}
+
 VALUE
 rb_ary_freeze(ary)
     VALUE ary;
@@ -79,14 +94,14 @@ rb_ary_s_alloc(klass)
     OBJSETUP(ary, klass, T_ARRAY);
 
     ary->len = 0;
-    ary->capa = 0;
     ary->ptr = 0;
+    ary->aux.capa = 0;
 
     return (VALUE)ary;
 }
 
-VALUE
-rb_ary_new0(klass, len)
+static VALUE
+ary_new(klass, len)
     VALUE klass;
     long len;
 {
@@ -100,7 +115,7 @@ rb_ary_new0(klass, len)
     }
     if (len == 0) len++;
     RARRAY(ary)->ptr = ALLOC_N(VALUE, len);
-    RARRAY(ary)->capa = len;
+    RARRAY(ary)->aux.capa = len;
 
     return ary;
 }
@@ -109,7 +124,7 @@ VALUE
 rb_ary_new2(len)
     long len;
 {
-    return rb_ary_new0(rb_cArray, len);
+    return ary_new(rb_cArray, len);
 }
 
 
@@ -228,9 +243,9 @@ rb_ary_initialize(argc, argv, ary)
     if (len > 0 && len*sizeof(VALUE) <= 0) {
 	rb_raise(rb_eArgError, "array size too big");
     }
-    if (len > RARRAY(ary)->capa) {
-	RARRAY(ary)->capa = len;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+    if (len > RARRAY(ary)->aux.capa) {
+	RARRAY(ary)->aux.capa = len;
+	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
     }
     memfill(RARRAY(ary)->ptr, len, val);
     RARRAY(ary)->len = len;
@@ -250,7 +265,7 @@ rb_ary_s_create(argc, argv, klass)
 	RARRAY(ary)->ptr = ALLOC_N(VALUE, argc);
 	MEMCPY(RARRAY(ary)->ptr, argv, VALUE, argc);
     }
-    RARRAY(ary)->len = RARRAY(ary)->capa = argc;
+    RARRAY(ary)->len = RARRAY(ary)->aux.capa = argc;
 
     return ary;
 }
@@ -270,13 +285,13 @@ rb_ary_store(ary, idx, val)
 	}
     }
 
-    if (idx >= RARRAY(ary)->capa) {
-	long capa_inc = RARRAY(ary)->capa / 2;
+    if (idx >= RARRAY(ary)->aux.capa) {
+	long capa_inc = RARRAY(ary)->aux.capa / 2;
 	if (capa_inc < ARY_DEFAULT_SIZE) {
 	    capa_inc = ARY_DEFAULT_SIZE;
 	}
-	RARRAY(ary)->capa = idx + capa_inc;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+	RARRAY(ary)->aux.capa = idx + capa_inc;
+	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
     }
     if (idx > RARRAY(ary)->len) {
 	rb_mem_clear(RARRAY(ary)->ptr+RARRAY(ary)->len,
@@ -319,34 +334,45 @@ VALUE
 rb_ary_pop(ary)
     VALUE ary;
 {
-    rb_ary_modify(ary);
+    rb_ary_modify_check(ary);
     if (RARRAY(ary)->len == 0) return Qnil;
-    if (RARRAY(ary)->len * 10 < RARRAY(ary)->capa && RARRAY(ary)->capa > ARY_DEFAULT_SIZE) {
-	RARRAY(ary)->capa = RARRAY(ary)->len * 2;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+    if (RARRAY(ary)->len * 10 < RARRAY(ary)->aux.capa && RARRAY(ary)->aux.capa > ARY_DEFAULT_SIZE) {
+	RARRAY(ary)->aux.capa = RARRAY(ary)->len * 2;
+	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
     }
     return RARRAY(ary)->ptr[--RARRAY(ary)->len];
 }
 
+static void
+ary_make_shared(ary)
+    VALUE ary;
+{
+    if (FL_TEST(ary, ELTS_SHARED)) return;
+    else {
+	NEWOBJ(shared, struct RArray);
+	OBJSETUP(shared, rb_cArray, T_ARRAY);
+
+	shared->len = RARRAY(ary)->len;
+	shared->ptr = RARRAY(ary)->ptr;
+	shared->aux.capa = RARRAY(ary)->aux.capa;
+	RARRAY(ary)->aux.shared = (VALUE)shared;
+	FL_SET(ary, ELTS_SHARED);
+    }
+}
+
 VALUE
 rb_ary_shift(ary)
     VALUE ary;
 {
     VALUE top;
 
-    rb_ary_modify(ary);
+    rb_ary_modify_check(ary);
     if (RARRAY(ary)->len == 0) return Qnil;
-
     top = RARRAY(ary)->ptr[0];
+    ary_make_shared(ary);
+    RARRAY(ary)->ptr++;		/* shift ptr */
     RARRAY(ary)->len--;
 
-    /* sliding items */
-    MEMMOVE(RARRAY(ary)->ptr, RARRAY(ary)->ptr+1, VALUE, RARRAY(ary)->len);
-    if (RARRAY(ary)->len * 10 < RARRAY(ary)->capa && RARRAY(ary)->capa > ARY_DEFAULT_SIZE) {
-	RARRAY(ary)->capa = RARRAY(ary)->len * 2;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
-    }
-
     return top;
 }
 
@@ -355,13 +381,13 @@ rb_ary_unshift(ary, item)
     VALUE ary, item;
 {
     rb_ary_modify(ary);
-    if (RARRAY(ary)->len >= RARRAY(ary)->capa) {
-	long capa_inc = RARRAY(ary)->capa / 2;
+    if (RARRAY(ary)->len >= RARRAY(ary)->aux.capa) {
+	long capa_inc = RARRAY(ary)->aux.capa / 2;
 	if (capa_inc < ARY_DEFAULT_SIZE) {
 	    capa_inc = ARY_DEFAULT_SIZE;
 	}
-	RARRAY(ary)->capa+=capa_inc;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+	RARRAY(ary)->aux.capa+=capa_inc;
+	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
     }
 
     /* sliding items */
@@ -429,11 +455,14 @@ rb_ary_subseq(ary, beg, len)
 	len = 0;
     }
     klass = rb_obj_class(ary);
-    if (len == 0) return rb_ary_new0(klass,0);
+    if (len == 0) return ary_new(klass,0);
 
-    ary2 = rb_ary_new0(klass, len);
-    MEMCPY(RARRAY(ary2)->ptr, RARRAY(ary)->ptr+beg, VALUE, len);
+    ary_make_shared(ary);
+    ary2 = rb_obj_alloc(klass);
+    RARRAY(ary2)->ptr = RARRAY(ary)->ptr+beg;
     RARRAY(ary2)->len = len;
+    RARRAY(ary2)->aux.shared = RARRAY(ary)->aux.shared;
+    FL_SET(ary2, ELTS_SHARED);
 
     return ary2;
 }
@@ -609,9 +638,9 @@ rb_ary_update(ary, beg, len, rpl)
     rb_ary_modify(ary);
     if (beg >= RARRAY(ary)->len) {
 	len = beg + rlen;
-	if (len >= RARRAY(ary)->capa) {
-	    RARRAY(ary)->capa=len;
-	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+	if (len >= RARRAY(ary)->aux.capa) {
+	    RARRAY(ary)->aux.capa=len;
+	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
 	}
 	rb_mem_clear(RARRAY(ary)->ptr+RARRAY(ary)->len, beg-RARRAY(ary)->len);
 	MEMCPY(RARRAY(ary)->ptr+beg, RARRAY(rpl)->ptr, VALUE, rlen);
@@ -625,9 +654,9 @@ rb_ary_update(ary, beg, len, rpl)
 	}
 
 	alen = RARRAY(ary)->len + rlen - len;
-	if (alen >= RARRAY(ary)->capa) {
-	    RARRAY(ary)->capa = alen;
-	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+	if (alen >= RARRAY(ary)->aux.capa) {
+	    RARRAY(ary)->aux.capa = alen;
+	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
 	}
 
 	if (len != rlen) {
@@ -749,32 +778,51 @@ rb_ary_empty_p(ary)
 }
 
 static VALUE
-rb_ary_clone(ary)
+ary_copy(ary, clone)
     VALUE ary;
+    int clone;
 {
-    VALUE clone = rb_ary_new2(RARRAY(ary)->len);
+    VALUE copy;
+
+    ary_make_shared(ary);
+    copy = rb_obj_alloc(rb_cArray);
+    if (clone) CLONESETUP(copy, ary);
+    else DUPSETUP(copy, ary);
+    RARRAY(copy)->ptr = RARRAY(ary)->ptr;
+    RARRAY(copy)->len = RARRAY(ary)->len;
+    RARRAY(copy)->aux.shared = RARRAY(ary)->aux.shared;
+    FL_SET(copy, ELTS_SHARED);
+
+    return copy;
+}
 
-    CLONESETUP(clone, ary);
-    MEMCPY(RARRAY(clone)->ptr, RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
-    RARRAY(clone)->len = RARRAY(ary)->len;
-    return clone;
+static VALUE
+rb_ary_clone(ary)
+    VALUE ary;
+{
+    return ary_copy(ary, Qtrue);
 }
 
 VALUE
 rb_ary_dup(ary)
     VALUE ary;
 {
+    return ary_copy(ary, Qfalse);
+}
+
+static VALUE
+ary_dup(ary)
+    VALUE ary;
+{
     VALUE dup = rb_ary_new2(RARRAY(ary)->len);
 
-    OBJSETUP(dup, rb_obj_class(ary), T_ARRAY);
+    DUPSETUP(dup, ary);
     MEMCPY(RARRAY(dup)->ptr, RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
     RARRAY(dup)->len = RARRAY(ary)->len;
-    OBJ_INFECT(dup, ary);
     return dup;
 }
 
 extern VALUE rb_output_fs;
-extern VALUE rb_default_rs;
 
 static VALUE
 inspect_join(ary, arg)
@@ -861,9 +909,6 @@ rb_ary_to_s(ary)
 
     if (RARRAY(ary)->len == 0) return rb_str_new(0, 0);
     sep = rb_output_fs;
-#if 1
-    if (NIL_P(rb_output_fs)) sep = rb_default_rs; /* newline */
-#endif
     str = rb_ary_join(ary, sep);
     return str;
 }
@@ -1006,7 +1051,7 @@ static VALUE
 rb_ary_reverse_m(ary)
     VALUE ary;
 {
-    return rb_ary_reverse(rb_ary_dup(ary));
+    return rb_ary_reverse(ary_dup(ary));
 }
 
 int
@@ -1018,8 +1063,8 @@ rb_cmpint(cmp)
 	if (RBIGNUM(cmp)->sign) return 1;
 	return -1;
     }
-    if (rb_funcall(cmp, '>', 1, INT2FIX(0))) return 1;
-    if (rb_funcall(cmp, '<', 1, INT2FIX(0))) return -1;
+    if (rb_funcall(id_cmp, '>', 1, INT2FIX(0))) return 1;
+    if (rb_funcall(id_cmp, '<', 1, INT2FIX(0))) return -1;
     return 0;
 }
 
@@ -1044,7 +1089,7 @@ sort_2(a, b)
 	return rb_str_cmp(*a, *b);
     }
 
-    retval = rb_funcall(*a, cmp, 1, *b);
+    retval = rb_funcall(*a, id_cmp, 1, *b);
     return rb_cmpint(retval);
 }
 
@@ -1081,32 +1126,12 @@ VALUE
 rb_ary_sort(ary)
     VALUE ary;
 {
-    ary = rb_ary_dup(ary);
+    ary = ary_dup(ary);
     rb_ary_sort_bang(ary);
     return ary;
 }
 
 static VALUE
-sort_inplace(ary)
-    VALUE ary;
-{
-    qsort(RARRAY(ary)->ptr, RARRAY(ary)->len, sizeof(VALUE),sort_2);
-    return ary;
-}
-
-VALUE
-rb_ary_sort_inplace(ary)
-    VALUE ary;
-{
-    rb_ary_modify(ary);
-    if (RARRAY(ary)->len <= 1) return ary;
-
-    FL_SET(ary, ARY_TMPLOCK);	/* prohibit modification during sort */
-    rb_ensure(sort_inplace, ary, sort_unlock, ary);
-    return ary;
-}
-
-static VALUE
 rb_ary_collect(ary)
     VALUE ary;
 {
@@ -1269,7 +1294,7 @@ static VALUE
 rb_ary_reject(ary)
     VALUE ary;
 {
-    ary = rb_ary_dup(ary);
+    ary = ary_dup(ary);
     rb_ary_reject_bang(ary);
     return ary;
 }
@@ -1297,9 +1322,9 @@ rb_ary_clear(ary)
 {
     rb_ary_modify(ary);
     RARRAY(ary)->len = 0;
-    if (ARY_DEFAULT_SIZE*3 < RARRAY(ary)->capa) {
-	RARRAY(ary)->capa = ARY_DEFAULT_SIZE * 2;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+    if (ARY_DEFAULT_SIZE*3 < RARRAY(ary)->aux.capa) {
+	RARRAY(ary)->aux.capa = ARY_DEFAULT_SIZE * 2;
+	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
     }
     return ary;
 }
@@ -1337,9 +1362,9 @@ rb_ary_fill(argc, argv, ary)
     rb_ary_modify(ary);
     end = beg + len;
     if (end > RARRAY(ary)->len) {
-	if (end >= RARRAY(ary)->capa) {
-	    RARRAY(ary)->capa = end;
-	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+	if (end >= RARRAY(ary)->aux.capa) {
+	    RARRAY(ary)->aux.capa = end;
+	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->aux.capa);
 	}
 	if (beg > RARRAY(ary)->len) {
 	    rb_mem_clear(RARRAY(ary)->ptr+RARRAY(ary)->len,end-RARRAY(ary)->len);
@@ -1397,7 +1422,7 @@ rb_ary_times(ary, times)
     }
     len *= RARRAY(ary)->len;
 
-    ary2 = rb_ary_new0(rb_obj_class(ary), len);
+    ary2 = ary_new(rb_obj_class(ary), len);
     RARRAY(ary2)->len = len;
 
     for (i=0; i<len; i+=RARRAY(ary)->len) {
@@ -1521,7 +1546,7 @@ rb_ary_cmp(ary, ary2)
 	len = RARRAY(ary2)->len;
     }
     for (i=0; i<len; i++) {
-	VALUE v = rb_funcall(RARRAY(ary)->ptr[i],cmp,1,RARRAY(ary2)->ptr[i]);
+	VALUE v = rb_funcall(RARRAY(ary)->ptr[i],id_cmp,1,RARRAY(ary2)->ptr[i]);
 	if (v != INT2FIX(0)) {
 	    return v;
 	}
@@ -1646,7 +1671,7 @@ static VALUE
 rb_ary_uniq(ary)
     VALUE ary;
 {
-    ary = rb_ary_dup(ary);
+    ary = ary_dup(ary);
     rb_ary_uniq_bang(ary);
     return ary;
 }
@@ -1667,7 +1692,7 @@ rb_ary_compact_bang(ary)
     if (RARRAY(ary)->len == (p - RARRAY(ary)->ptr)) {
 	return Qnil;
     }
-    RARRAY(ary)->len = RARRAY(ary)->capa = (p - RARRAY(ary)->ptr);
+    RARRAY(ary)->len = RARRAY(ary)->aux.capa = (p - RARRAY(ary)->ptr);
     REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
 
     return ary;
@@ -1677,7 +1702,7 @@ static VALUE
 rb_ary_compact(ary)
     VALUE ary;
 {
-    ary = rb_ary_dup(ary);
+    ary = ary_dup(ary);
     rb_ary_compact_bang(ary);
     return ary;
 }
@@ -1755,7 +1780,7 @@ static VALUE
 rb_ary_flatten(ary)
     VALUE ary;
 {
-    ary = rb_ary_dup(ary);
+    ary = ary_dup(ary);
     rb_ary_flatten_bang(ary);
     return ary;
 }
@@ -1847,5 +1872,5 @@ Init_Array()
     rb_define_method(rb_cArray, "flatten!", rb_ary_flatten_bang, 0);
     rb_define_method(rb_cArray, "nitems", rb_ary_nitems, 0);
 
-    cmp = rb_intern("<=>");
+    id_cmp = rb_intern("<=>");
 }
diff --git a/class.c b/class.c
index 31d72757a0..48577a79ec 100644
--- a/class.c
+++ b/class.c
@@ -87,7 +87,8 @@ rb_mod_dup(mod)
     VALUE mod;
 {
     VALUE dup = rb_mod_clone(mod);
-    OBJSETUP(dup, RBASIC(mod)->klass, BUILTIN_TYPE(mod));
+
+    DUPSETUP(dup, mod);
     if (FL_TEST(mod, FL_SINGLETON)) {
 	FL_SET(dup, FL_SINGLETON);
     }
diff --git a/enum.c b/enum.c
index 352771fcaa..9e0cf19fc0 100644
--- a/enum.c
+++ b/enum.c
@@ -12,6 +12,7 @@
 
 #include "ruby.h"
 #include "node.h"
+#include "util.h"
 
 VALUE rb_mEnumerable;
 static ID id_each, id_eqq, id_cmp;
@@ -204,53 +205,41 @@ enum_sort(obj)
 }
 
 static VALUE
-sort_by_i(i, memo)
-    VALUE i;
-    NODE *memo;
+sort_by_i(i, ary)
+    VALUE i, ary;
 {
     VALUE v, e;
 
     v = rb_yield(i);
-    if (TYPE(v) == T_ARRAY) {
-	int j, len = RARRAY(v)->len;
-
-	e = rb_ary_new2(len+2);
-	for (j=0; j<len; j++) {
-	    RARRAY(e)->ptr[j] = RARRAY(v)->ptr[j];
-	}
-	RARRAY(e)->ptr[j++] = INT2NUM(memo->u3.cnt);
-	RARRAY(e)->ptr[j] = i;
-	RARRAY(e)->len = len + 2;
-    }
-    else {
-	e = rb_ary_new3(3, v, INT2NUM(memo->u3.cnt), i);
-    }
-    rb_ary_push(memo->u1.value, e);
-    memo->u3.cnt++;
+    e = rb_assoc_new(v, i);
+    rb_ary_push(ary, e);
     return Qnil;
 }
 
-static VALUE
-sort_by_sort_body(a)
-    VALUE a;
+static int
+sort_by_cmp(a, b)
+    VALUE *a, *b;
 {
-    return rb_ary_cmp(RARRAY(a)->ptr[0], RARRAY(a)->ptr[1]);
+    VALUE retval;
+
+    retval = rb_funcall(RARRAY(*a)->ptr[0], id_cmp, 1, RARRAY(*b)->ptr[0]);
+    return rb_cmpint(retval);
 }
 
 static VALUE
 enum_sort_by(obj)
     VALUE obj;
 {
-    VALUE ary = rb_ary_new2(2000);
-    NODE *memo = rb_node_newnode(NODE_MEMO, ary, 0, 0);
+    VALUE ary;
     long i;
 
-    rb_iterate(rb_each, obj, sort_by_i, (VALUE)memo);
-    rb_gc_force_recycle((VALUE)memo);
-    rb_ary_sort_inplace(ary);
+    ary  = rb_ary_new2((TYPE(obj) == T_ARRAY) ? RARRAY(obj)->len : 2000);
+    rb_iterate(rb_each, obj, sort_by_i, ary);
+    if (RARRAY(ary)->len <= 1) return ary;
+    qsort(RARRAY(ary)->ptr, RARRAY(ary)->len, sizeof(VALUE), sort_by_cmp);
     for (i=0; i<RARRAY(ary)->len; i++) {
 	VALUE e = RARRAY(ary)->ptr[i];
-	RARRAY(ary)->ptr[i] = RARRAY(e)->ptr[RARRAY(e)->len - 1];
+	RARRAY(ary)->ptr[i] = RARRAY(e)->ptr[1];
     }
 
     return ary;
diff --git a/error.c b/error.c
index 4d56f80e70..010a27243a 100644
--- a/error.c
+++ b/error.c
@@ -718,6 +718,10 @@ rb_sys_fail(mesg)
     int n = errno;
     VALUE ee;
 
+    if (errno == 0) {
+	rb_bug("rb_sys_fail() - errno == 0");
+    }
+
     err = strerror(errno);
     if (mesg) {
 	volatile VALUE tmp = rb_str_inspect(rb_str_new2(mesg));
diff --git a/ext/curses/curses.c b/ext/curses/curses.c
index c756c47caa..c1523823b6 100644
--- a/ext/curses/curses.c
+++ b/ext/curses/curses.c
@@ -460,18 +460,20 @@ static VALUE
 curses_curs_set(VALUE obj, VALUE visibility)
 {
   int n;
-  return (n = curs_set(FIX2INT(visibility)) != ERR) ? INT2FIX(n) : Qnil;
+  return (n = curs_set(NUM2INT(visibility)) != ERR) ? INT2FIX(n) : Qnil;
 }
 
 static VALUE
 curses_scrl(VALUE obj, VALUE n)
 {
+  /* may have to raise exception on ERR */
   return (scrl(NUM2INT(n)) == OK) ? Qtrue : Qfalse;
 }
 
 static VALUE
 curses_setscrreg(VALUE obj, VALUE top, VALUE bottom)
 {
+  /* may have to raise exception on ERR */
   return (setscrreg(NUM2INT(top), NUM2INT(bottom)) == OK) ? Qtrue : Qfalse;
 }
 
@@ -479,21 +481,21 @@ static VALUE
 curses_attroff(VALUE obj, VALUE attrs)
 {
   return window_attroff(rb_stdscr,attrs);  
-  /* return INT2FIX(attroff(FIX2INT(attrs))); */
+  /* return INT2FIX(attroff(NUM2INT(attrs))); */
 }
 
 static VALUE
 curses_attron(VALUE obj, VALUE attrs)
 {
   return window_attron(rb_stdscr,attrs);
-  /* return INT2FIX(attroff(FIX2INT(attrs))); */
+  /* return INT2FIX(attroff(NUM2INT(attrs))); */
 }
 
 static VALUE
 curses_attrset(VALUE obj, VALUE attrs)
 {
   return window_attrset(rb_stdscr,attrs);
-  /* return INT2FIX(attroff(FIX2INT(attrs))); */
+  /* return INT2FIX(attroff(NUM2INT(attrs))); */
 }
 
 static VALUE
@@ -513,20 +515,23 @@ curses_bkgd(VALUE obj, VALUE ch)
 static VALUE
 curses_start_color(VALUE obj)
 {
+  /* may have to raise exception on ERR */
   return (start_color() == OK) ? Qtrue : Qfalse;
 }
 
 static VALUE
 curses_init_pair(VALUE obj, VALUE pair, VALUE f, VALUE b)
 {
-  return (init_pair(FIX2INT(pair),FIX2INT(f),FIX2INT(b)) == OK) ? Qtrue : Qfalse;
+  /* may have to raise exception on ERR */
+  return (init_pair(NUM2INT(pair),NUM2INT(f),NUM2INT(b)) == OK) ? Qtrue : Qfalse;
 }
 
 static VALUE
 curses_init_color(VALUE obj, VALUE color, VALUE r, VALUE g, VALUE b)
 {
-  return (init_color(FIX2INT(color),FIX2INT(r),
-		     FIX2INT(g),FIX2INT(b)) == OK) ? Qtrue : Qfalse;
+  /* may have to raise exception on ERR */
+  return (init_color(NUM2INT(color),NUM2INT(r),
+		     NUM2INT(g),NUM2INT(b)) == OK) ? Qtrue : Qfalse;
 }
 
 static VALUE
@@ -546,7 +551,7 @@ curses_color_content(VALUE obj, VALUE color)
 {
   short r,g,b;
 
-  color_content(FIX2INT(color),&r,&g,&b);
+  color_content(NUM2INT(color),&r,&g,&b);
   return rb_ary_new3(3,INT2FIX(r),INT2FIX(g),INT2FIX(b));
 }
 
@@ -555,20 +560,20 @@ curses_pair_content(VALUE obj, VALUE pair)
 {
   short f,b;
 
-  pair_content(FIX2INT(pair),&f,&b);
+  pair_content(NUM2INT(pair),&f,&b);
   return rb_ary_new3(2,INT2FIX(f),INT2FIX(b));
 }
 
 static VALUE
 curses_color_pair(VALUE obj, VALUE attrs)
 {
-  return INT2FIX(COLOR_PAIR(FIX2INT(attrs)));
+  return INT2FIX(COLOR_PAIR(NUM2INT(attrs)));
 }
 
 static VALUE
 curses_pair_number(VALUE obj, VALUE attrs)
 {
-  return INT2FIX(PAIR_NUMBER(FIX2INT(attrs)));
+  return INT2FIX(PAIR_NUMBER(NUM2INT(attrs)));
 }
 #endif
 
@@ -591,7 +596,7 @@ no_mevent()
 static void
 curses_mousedata_free(struct mousedata *mdata)
 {
-  if( mdata->mevent )
+  if (mdata->mevent)
     free(mdata->mevent);
 };
 
@@ -604,7 +609,7 @@ curses_getmouse(VALUE obj)
   val = Data_Make_Struct(cMouseEvent,struct mousedata,
 			 0,curses_mousedata_free,mdata);
   mdata->mevent = (MEVENT*)malloc(sizeof(MEVENT));
-  return ( getmouse(mdata->mevent) == OK ) ? val : Qnil;
+  return (getmouse(mdata->mevent) == OK) ? val : Qnil;
 };
 
 static VALUE
@@ -898,8 +903,8 @@ window_box(argc, argv, self)
 
       c = NUM2CHR(corn);
       getyx(winp->window, cur_y, cur_x);
-      x = FIX2INT(window_maxx(self)) - 1;
-      y = FIX2INT(window_maxy(self)) - 1;
+      x = NUM2INT(window_maxx(self)) - 1;
+      y = NUM2INT(window_maxy(self)) - 1;
       wmove(winp->window, 0, 0);
       waddch(winp->window, c);
       wmove(winp->window, y, 0);
@@ -1062,11 +1067,10 @@ static VALUE
 window_scrollok(VALUE obj, VALUE bf)
 {
   struct windata *winp;
-  int res;
 
   GetWINDOW(obj, winp);
-  res = scrollok(winp->window, (bf == Qtrue) ? TRUE : FALSE);
-  return (res == OK) ? Qtrue : Qfalse;
+  scrollok(winp->window, RTEST(bf) ? TRUE : FALSE);
+  return Qnil;
 }
 
 static VALUE
@@ -1076,8 +1080,8 @@ window_idlok(VALUE obj, VALUE bf)
   int res;
 
   GetWINDOW(obj, winp);
-  res = idlok(winp->window, (bf == Qtrue) ? TRUE : FALSE);
-  return (res == OK) ? Qtrue : Qfalse;
+  idlok(winp->window, RTEST(bf) ? TRUE : FALSE);
+  return Qnil;
 }
 
 static VALUE
@@ -1088,6 +1092,7 @@ window_setscrreg(VALUE obj, VALUE top, VALUE bottom)
 
   GetWINDOW(obj, winp);
   res = wsetscrreg(winp->window, NUM2INT(top), NUM2INT(bottom));
+  /* may have to raise exception on ERR */
   return (res == OK) ? Qtrue : Qfalse;
 };
 
@@ -1097,6 +1102,7 @@ window_scroll(VALUE obj)
   struct windata *winp;
 
   GetWINDOW(obj, winp);
+  /* may have to raise exception on ERR */
   return (scroll(winp->window) == OK) ? Qtrue : Qfalse;
 }
 
@@ -1106,6 +1112,7 @@ window_scrl(VALUE obj, VALUE n)
   struct windata *winp;
 
   GetWINDOW(obj, winp);
+  /* may have to raise exception on ERR */
   return (wscrl(winp->window,NUM2INT(n)) == OK) ? Qtrue : Qfalse;
 }
 
@@ -1115,7 +1122,7 @@ window_attroff(VALUE obj, VALUE attrs)
   struct windata *winp;
 
   GetWINDOW(obj,winp);
-  return INT2FIX(wattroff(winp->window,FIX2INT(attrs)));
+  return INT2FIX(wattroff(winp->window,NUM2INT(attrs)));
 };
 
 static VALUE
@@ -1125,10 +1132,10 @@ window_attron(VALUE obj, VALUE attrs)
   VALUE val;
 
   GetWINDOW(obj,winp);
-  val = INT2FIX(wattron(winp->window,FIX2INT(attrs)));
+  val = INT2FIX(wattron(winp->window,NUM2INT(attrs)));
   if( rb_block_given_p() ){
     rb_yield(val);
-    wattroff(winp->window,FIX2INT(attrs));
+    wattroff(winp->window,NUM2INT(attrs));
     return val;
   }
   else{
@@ -1142,7 +1149,7 @@ window_attrset(VALUE obj, VALUE attrs)
   struct windata *winp;
 
   GetWINDOW(obj,winp);
-  return INT2FIX(wattrset(winp->window,FIX2INT(attrs)));
+  return INT2FIX(wattrset(winp->window,NUM2INT(attrs)));
 }
 
 static VALUE
@@ -1182,10 +1189,11 @@ window_keypad(VALUE obj, VALUE val)
   GetWINDOW(obj,winp);
   /* keypad() of NetBSD's libcurses returns no value */
 #if defined(__NetBSD__) && !defined(NCURSES_VERSION)
-  keypad(winp->window,(val == Qtrue ? TRUE : FALSE));
+  keypad(winp->window,(RTEST(val) ? TRUE : FALSE));
   return Qnil;
 #else
-  return (keypad(winp->window,(val == Qtrue) ? TRUE : FALSE)) == OK ?
+  /* may have to raise exception on ERR */
+  return (keypad(winp->window,RTEST(val) ? TRUE : FALSE)) == OK ?
     Qtrue : Qfalse;
 #endif
 };
diff --git a/gc.c b/gc.c
index e73fad4089..4b72db951d 100644
--- a/gc.c
+++ b/gc.c
@@ -756,6 +756,8 @@ rb_gc_mark_children(ptr)
 	    for (i=0; i < len; i++)
 		rb_gc_mark(*ptr++);
 	}
+	if (FL_TEST(obj, ELTS_SHARED))
+	    rb_gc_mark(obj->as.array.aux.shared);
 	break;
 
       case T_HASH:
@@ -764,8 +766,9 @@ rb_gc_mark_children(ptr)
 	break;
 
       case T_STRING:
-	if (obj->as.string.orig) {
-	    rb_gc_mark((VALUE)obj->as.string.orig);
+#define STR_ASSOC FL_USER2   /* copied from string.c */
+	if (FL_TEST(obj, ELTS_SHARED|STR_ASSOC)) {
+	    rb_gc_mark(obj->as.string.aux.shared);
 	}
 	break;
 
@@ -945,13 +948,12 @@ obj_free(obj)
 	}
 	break;
       case T_STRING:
-#define STR_NO_ORIG FL_USER2   /* copied from string.c */
-	if (!RANY(obj)->as.string.orig || FL_TEST(obj, STR_NO_ORIG)) {
+	if (RANY(obj)->as.string.ptr && !FL_TEST(obj, ELTS_SHARED)) {
 	    RUBY_CRITICAL(free(RANY(obj)->as.string.ptr));
 	}
 	break;
       case T_ARRAY:
-	if (RANY(obj)->as.array.ptr) {
+	if (RANY(obj)->as.array.ptr && !FL_TEST(obj, ELTS_SHARED)) {
 	    RUBY_CRITICAL(free(RANY(obj)->as.array.ptr));
 	}
 	break;
diff --git a/hash.c b/hash.c
index 9ac14e87d5..94c7e33a33 100644
--- a/hash.c
+++ b/hash.c
@@ -18,6 +18,7 @@
 #include "rubysig.h"
 
 #define HASH_DELETED  FL_USER1
+#define HASH_PROC_DEFAULT FL_USER2
 
 static void
 rb_hash_modify(hash)
@@ -38,13 +39,13 @@ rb_hash_freeze(hash)
 VALUE rb_cHash;
 
 static VALUE envtbl;
-static ID hash;
+static ID id_hash, id_yield, id_default;
 
 VALUE
 rb_hash(obj)
     VALUE obj;
 {
-    return rb_funcall(obj, hash, 0);
+    return rb_funcall(obj, id_hash, 0);
 }
 
 static VALUE
@@ -93,7 +94,7 @@ rb_any_hash(a)
 
       default:
 	DEFER_INTS;
-	hval = rb_funcall(a, hash, 0);
+	hval = rb_funcall(a, id_hash, 0);
 	if (FIXNUM_P(hval)) {
 	    hval %= 536870917;
 	}
@@ -198,9 +199,18 @@ rb_hash_initialize(argc, argv, hash)
 {
     VALUE ifnone;
 
-    rb_scan_args(argc, argv, "01", &ifnone);
     rb_hash_modify(hash);
-    RHASH(hash)->ifnone = ifnone;
+    if (rb_block_given_p()) {
+	if (argc > 1) {
+	    rb_raise(rb_eArgError, "wrong number of arguments", argc);
+	}
+	RHASH(hash)->ifnone = rb_f_lambda();
+	FL_SET(hash, HASH_PROC_DEFAULT);
+    }
+    else {
+	rb_scan_args(argc, argv, "01", &ifnone);
+	RHASH(hash)->ifnone = ifnone;
+    }
 
     return hash;
 }
@@ -284,7 +294,7 @@ rb_hash_aref(hash, key)
     VALUE val;
 
     if (!st_lookup(RHASH(hash)->tbl, key, &val)) {
-	return RHASH(hash)->ifnone;
+	return rb_funcall(hash, id_default, 1, key);
     }
     return val;
 }
@@ -316,9 +326,17 @@ rb_hash_fetch(argc, argv, hash)
 }
 
 static VALUE
-rb_hash_default(hash)
+rb_hash_default(argc, argv, hash)
+    int argc;
+    VALUE *argv;
     VALUE hash;
 {
+    VALUE key;
+
+    rb_scan_args(argc, argv, "01", &key);
+    if (FL_TEST(hash, HASH_PROC_DEFAULT)) {
+	return rb_funcall(RHASH(hash)->ifnone, id_yield, 2, hash, key);
+    }
     return RHASH(hash)->ifnone;
 }
 
@@ -328,6 +346,7 @@ rb_hash_set_default(hash, ifnone)
 {
     rb_hash_modify(hash);
     RHASH(hash)->ifnone = ifnone;
+    FL_UNSET(hash, HASH_PROC_DEFAULT);
     return hash;
 }
 
@@ -392,7 +411,7 @@ rb_hash_delete(hash, key)
     if (rb_block_given_p()) {
 	return rb_yield(key);
     }
-    return RHASH(hash)->ifnone;
+    return Qnil;
 }
 
 struct shift_var {
@@ -1433,7 +1452,9 @@ env_reject()
 void
 Init_Hash()
 {
-    hash = rb_intern("hash");
+    id_hash = rb_intern("hash");
+    id_yield = rb_intern("yield");
+    id_default = rb_intern("default");
 
     rb_cHash = rb_define_class("Hash", rb_cObject);
 
@@ -1456,7 +1477,7 @@ Init_Hash()
     rb_define_method(rb_cHash,"fetch", rb_hash_fetch, -1);
     rb_define_method(rb_cHash,"[]=", rb_hash_aset, 2);
     rb_define_method(rb_cHash,"store", rb_hash_aset, 2);
-    rb_define_method(rb_cHash,"default", rb_hash_default, 0);
+    rb_define_method(rb_cHash,"default", rb_hash_default, -1);
     rb_define_method(rb_cHash,"default=", rb_hash_set_default, 1);
     rb_define_method(rb_cHash,"index", rb_hash_index, 1);
     rb_define_method(rb_cHash,"indexes", rb_hash_indexes, -1);
diff --git a/io.c b/io.c
index 3732e0632b..0984fdfe02 100644
--- a/io.c
+++ b/io.c
@@ -513,6 +513,10 @@ io_fread(ptr, len, f)
 	  eof:
 	    if (ferror(f)) {
 		if (errno == EINTR) continue;
+		if (errno == EAGAIN) return len - n;
+#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
+		if (errno == EWOULDBLOCK) return len - n;
+#endif
 		rb_sys_fail(0);
 	    }
 	    *ptr = '\0';
@@ -2187,6 +2191,25 @@ rb_f_putc(recv, ch)
     return rb_io_putc(rb_defout, ch);
 }
 
+static VALUE rb_io_puts _((int, VALUE*, VALUE));
+
+static VALUE
+io_puts_ary(ary, out)
+    VALUE ary, out;
+{
+    VALUE tmp;
+    int i;
+
+    for (i=0; i<RARRAY(ary)->len; i++) {
+	tmp = RARRAY(ary)->ptr[i];
+	if (rb_inspecting_p(tmp)) {
+	    tmp = rb_str_new2("[...]");
+	}
+	rb_io_puts(1, &tmp, out);
+    }
+    return Qnil;
+}
+
 static VALUE
 rb_io_puts(argc, argv, out)
     int argc;
@@ -2206,11 +2229,11 @@ rb_io_puts(argc, argv, out)
 	    line = rb_str_new2("nil");
 	}
 	else {
-#if 0
-	    if (TYPE(argv[i]) == T_ARRAY) {
-		rb_warn("puts behavior changed for Array");
+	    line = rb_check_convert_type(argv[i], T_ARRAY, "Array", "to_ary");
+	    if (!NIL_P(line)) {
+		rb_protect_inspect(io_puts_ary, line, out);
+		continue;
 	    }
-#endif
 	    line = rb_obj_as_string(argv[i]);
 	}
 	rb_io_write(out, line);
diff --git a/object.c b/object.c
index 4020f54d03..7a4b1e208c 100644
--- a/object.c
+++ b/object.c
@@ -313,7 +313,6 @@ rb_obj_freeze(obj)
 	if (rb_safe_level() >= 4 && !OBJ_TAINTED(obj)) {
 	    rb_raise(rb_eSecurityError, "Insecure: can't freeze object");
 	}
-
 	OBJ_FREEZE(obj);
     }
     return obj;
@@ -1292,7 +1291,7 @@ Init_Object()
     rb_undef_method(rb_cClass, "append_features");
 
     rb_cData = rb_define_class("Data", rb_cObject);
-    rb_undef_method(CLASS_OF(rb_cData), "new");
+    rb_undef_method(CLASS_OF(rb_cData), "allocate");
 
     ruby_top_self = rb_obj_alloc(rb_cObject);
     rb_global_variable(&ruby_top_self);
diff --git a/parse.y b/parse.y
index e1c2dd46d1..96a7fd6edd 100644
--- a/parse.y
+++ b/parse.y
@@ -3938,6 +3938,10 @@ str_extend(list, term, paren)
 	  case '-':
 	    tokadd(c);
 	    c = nextc();
+	    if (!is_identchar(c)) {
+		pushback();
+		goto invalid_interporate;
+	    }
 	    tokadd(c);
 	    goto fetch_id;
 
@@ -3956,9 +3960,14 @@ str_extend(list, term, paren)
 		goto refetch;
 	    }
 	    if (!is_identchar(c)) {
-		yyerror("bad global variable in string");
-		newtok();
-		return list;
+	      invalid_interporate:
+		{
+		    VALUE s = rb_str_new2("#");
+		    rb_str_cat(s, tok(), toklen());
+		    list_append(list, NEW_STR(s));
+		    newtok();
+		    return list;
+		}
 	    }
 	}
 
@@ -3997,6 +4006,9 @@ str_extend(list, term, paren)
 	    c = nextc();
 	}
 	pushback(c);
+	if (toklen() == 1) {
+	    goto invalid_interporate;
+	}
 	break;
 
       case '{':
@@ -4264,7 +4276,9 @@ gettable(id)
 	return NEW_FALSE();
     }
     else if (id == k__FILE__) {
-	return NEW_STR(rb_str_new2(ruby_sourcefile));
+	VALUE f = rb_str_new2(ruby_sourcefile);
+	OBJ_FREEZE(f);
+	return NEW_STR(f);
     }
     else if (id == k__LINE__) {
 	return NEW_LIT(INT2FIX(ruby_sourceline));
diff --git a/regex.c b/regex.c
index ad5d88cc4f..b88bfffa4b 100644
--- a/regex.c
+++ b/regex.c
@@ -477,7 +477,7 @@ re_set_syntax(syntax)
   } while(0)
 
 #define WC2MBC1ST(c)							\
- ((c<0x100)?(c):((current_mbctype != MBCTYPE_UTF8)?(((c)>>8)&0xff):utf8_firstbyte(c)))
+ ((current_mbctype != MBCTYPE_UTF8) ? ((c<0x100) ? (c) : (((c)>>8)&0xff)) : utf8_firstbyte(c))
 
 static unsigned int
 utf8_firstbyte(c)
diff --git a/ruby.h b/ruby.h
index 65b4d3b2ef..d1f48959f5 100644
--- a/ruby.h
+++ b/ruby.h
@@ -247,6 +247,10 @@ VALUE rb_newobj _((void));
     rb_singleton_class_attached(RBASIC(clone)->klass, (VALUE)clone);\
     if (FL_TEST(obj, FL_EXIVAR)) rb_copy_generic_ivar((VALUE)clone,(VALUE)obj);\
 } while (0)
+#define DUPSETUP(dup,obj) do {\
+    OBJSETUP(dup,rb_obj_class(obj),(RBASIC(obj)->flags)&(T_MASK|FL_EXIVAR|FL_TAINT));\
+    if (FL_TEST(obj, FL_EXIVAR)) rb_copy_generic_ivar((VALUE)dup,(VALUE)obj);\
+} while (0)
 
 struct RBasic {
     unsigned long flags;
@@ -270,16 +274,25 @@ struct RFloat {
     double value;
 };
 
+#define ELTS_SHARED FL_USER2
+
 struct RString {
     struct RBasic basic;
     long len;
     char *ptr;
-    VALUE orig;
+    union {
+	int capa;
+	VALUE shared;
+    } aux;
 };
 
 struct RArray {
     struct RBasic basic;
-    long len, capa;
+    long len;
+    union {
+	int capa;
+	VALUE shared;
+    } aux;
     VALUE *ptr;
 };
 
diff --git a/sample/test.rb b/sample/test.rb
index 663a8695e1..a6ab98ca63 100644
--- a/sample/test.rb
+++ b/sample/test.rb
@@ -470,6 +470,18 @@ test_ok(($x * 0).join(":") == '')
 test_ok($x.size == 7)
 test_ok($x == [1, 2, 3, 4, 5, 6, 7])
 
+$x = [1,2,3]
+$x[1,0] = $x
+test_ok($x == [1,1,2,3,2,3])
+
+$x = [1,2,3]
+$x[-1,0] = $x
+test_ok($x == [1,2,1,2,3,3])
+
+$x = [1,2,3]
+$x.concat($x)
+test_ok($x == [1,2,3,1,2,3])
+
 test_check "hash"
 $x = {1=>2, 2=>4, 3=>6}
 $y = {1, 2, 2, 4, 3, 6}
@@ -505,17 +517,40 @@ $z = [1,2]
 $y[$z] = 256
 test_ok($y[$z] == 256)
 
-$x = [1,2,3]
-$x[1,0] = $x
-test_ok($x == [1,1,2,3,2,3])
-
-$x = [1,2,3]
-$x[-1,0] = $x
-test_ok($x == [1,2,1,2,3,3])
-
-$x = [1,2,3]
-$x.concat($x)
-test_ok($x == [1,2,3,1,2,3])
+$x = Hash.new(0)
+$x[1] = 1
+test_ok($x[1] == 1)
+test_ok($x[2] == 0)
+
+$x = Hash.new([])
+test_ok($x[22] == [])
+test_ok($x[22].equal?($x[22]))
+
+$x = Hash.new{[]}
+test_ok($x[22] == [])
+test_ok(!$x[22].equal?($x[22]))
+
+$x = Hash.new{|h,k| $z = k; h[k] = k*2}
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 22)
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 0)
+$x.default = 5
+test_ok($x[23] == 5)
+
+$x = Hash.new
+def $x.default(k)
+  $z = k
+  self[k] = k*2
+end
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 22)
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 0)
 
 test_check "iterator"
 
diff --git a/string.c b/string.c
index f1dd8b3b35..f3520813a0 100644
--- a/string.c
+++ b/string.c
@@ -27,7 +27,6 @@
 
 VALUE rb_cString;
 
-#define STR_NO_ORIG FL_USER2
 #define STR_ASSOC   FL_USER3
 
 VALUE rb_fs;
@@ -41,13 +40,13 @@ rb_str_s_alloc(klass)
 
     str->ptr = 0;
     str->len = 0;
-    str->orig = 0;
+    str->aux.capa = 0;
 
     return (VALUE)str;
 }
 
-VALUE
-rb_str_new0(klass, ptr, len)
+static VALUE
+str_new(klass, ptr, len)
     VALUE klass;
     const char *ptr;
     long len;
@@ -55,6 +54,7 @@ rb_str_new0(klass, ptr, len)
     VALUE str = rb_obj_alloc(klass);
 
     RSTRING(str)->len = len;
+    RSTRING(str)->aux.capa = len;
     RSTRING(str)->ptr = ALLOC_N(char,len+1);
     if (ptr) {
 	memcpy(RSTRING(str)->ptr, ptr, len);
@@ -68,7 +68,7 @@ rb_str_new(ptr, len)
     const char *ptr;
     long len;
 {
-    return rb_str_new0(rb_cString, ptr, len);
+    return str_new(rb_cString, ptr, len);
 }
 
 VALUE
@@ -99,51 +99,52 @@ rb_tainted_str_new2(ptr)
     return str;
 }
 
-VALUE
-rb_str_new3(str)
-    VALUE str;
+static VALUE
+str_new3(klass, str)
+    VALUE klass, str;
 {
-    VALUE str2 = rb_obj_alloc(rb_obj_class(str));
+    VALUE str2 = rb_obj_alloc(klass);
 
     RSTRING(str2)->len = RSTRING(str)->len;
     RSTRING(str2)->ptr = RSTRING(str)->ptr;
-    RSTRING(str2)->orig = str;
+    RSTRING(str2)->aux.shared = str;
+    FL_SET(str2, ELTS_SHARED);
     OBJ_INFECT(str2, str);
 
     return str2;
 }
 
 VALUE
+rb_str_new3(str)
+    VALUE str;
+{
+    return str_new3(rb_obj_class(str), str);
+}
+
+VALUE
 rb_str_new4(orig)
     VALUE orig;
 {
-    VALUE klass;
+    VALUE klass, str;
 
     klass = rb_obj_class(orig);
-    if (RSTRING(orig)->orig) {
-	VALUE str;
-
-	if (FL_TEST(orig, STR_NO_ORIG)) {
-	    str = rb_str_new0(klass, RSTRING(orig)->ptr, RSTRING(orig)->len);
-	}
-	else {
-	    str = rb_str_new3(RSTRING(orig)->orig);
-	    RBASIC(str)->klass = klass;
-	}
-	OBJ_FREEZE(str);
-	return str;
+    if (FL_TEST(orig, ELTS_SHARED)) {
+	str = str_new3(klass, RSTRING(orig)->aux.shared);
+    }
+    else if (FL_TEST(orig, STR_ASSOC)) {
+	str = str_new(klass, RSTRING(orig)->ptr, RSTRING(orig)->len);
     }
     else {
-	VALUE str = rb_obj_alloc(klass);
+	str = rb_obj_alloc(klass);
 
 	RSTRING(str)->len = RSTRING(orig)->len;
 	RSTRING(str)->ptr = RSTRING(orig)->ptr;
-	RSTRING(orig)->orig = str;
-	OBJ_INFECT(str, orig);
-	OBJ_FREEZE(str);
-
-	return str;
+	RSTRING(orig)->aux.shared = str;
+	FL_SET(orig, ELTS_SHARED);
     }
+    OBJ_INFECT(str, orig);
+    OBJ_FREEZE(str);
+    return str;
 }
 
 VALUE
@@ -152,7 +153,7 @@ rb_str_new5(obj, ptr, len)
     const char *ptr;
     long len;
 {
-    return rb_str_new0(rb_obj_class(obj), ptr, len);
+    return str_new(rb_obj_class(obj), ptr, len);
 }
 
 #define STR_BUF_MIN_SIZE 128
@@ -163,12 +164,11 @@ rb_str_buf_new(capa)
 {
     VALUE str = rb_obj_alloc(rb_cString);
 
-    FL_SET(str, STR_NO_ORIG);
     if (capa < STR_BUF_MIN_SIZE)
 	capa = STR_BUF_MIN_SIZE;
     RSTRING(str)->ptr = 0;
     RSTRING(str)->len = 0;
-    RSTRING(str)->orig = LONG2FIX(capa);
+    RSTRING(str)->aux.capa = capa;
     RSTRING(str)->ptr = ALLOC_N(char, capa+1);
     RSTRING(str)->ptr[0] = '\0';
 
@@ -210,16 +210,23 @@ rb_str_become(str, str2)
     if (NIL_P(str2)) {
 	RSTRING(str)->ptr = 0;
 	RSTRING(str)->len = 0;
-	RSTRING(str)->orig = 0;
+	RSTRING(str)->aux.capa = 0;
 	return;
     }
-    if ((!RSTRING(str)->orig||FL_TEST(str,STR_NO_ORIG))&&RSTRING(str)->ptr)
-	free(RSTRING(str)->ptr);
+    if (FL_TEST(str, ELTS_SHARED)) free(RSTRING(str)->ptr);
     RSTRING(str)->ptr = RSTRING(str2)->ptr;
     RSTRING(str)->len = RSTRING(str2)->len;
-    RSTRING(str)->orig = RSTRING(str2)->orig;
+    if (FL_TEST(str2, ELTS_SHARED|STR_ASSOC)) {
+	FL_SET(str, RBASIC(str2)->flags & (ELTS_SHARED|STR_ASSOC));
+	RSTRING(str)->aux.shared = RSTRING(str2)->aux.shared;
+    }
+    else {
+	RSTRING(str)->aux.capa = RSTRING(str2)->aux.capa;
+    }
     RSTRING(str2)->ptr = 0;	/* abandon str2 */
     RSTRING(str2)->len = 0;
+    RSTRING(str2)->aux.capa = 0;
+    FL_UNSET(str, ELTS_SHARED|STR_ASSOC);
     if (OBJ_TAINTED(str2)) OBJ_TAINT(str);
 }
 
@@ -227,22 +234,23 @@ void
 rb_str_associate(str, add)
     VALUE str, add;
 {
-    if (FL_TEST(str, STR_NO_ORIG|STR_ASSOC) != (STR_NO_ORIG|STR_ASSOC)) {
-	if (FL_TEST(str, STR_NO_ORIG)) {
+    if (FL_TEST(str, STR_ASSOC)) {
+	/* already associated */
+	rb_ary_concat(RSTRING(str)->aux.shared, add);
+    }
+    else {
+	if (FL_TEST(str, ELTS_SHARED)) {
+	    rb_str_modify(str);
+	}
+	else if (RSTRING(str)->aux.shared) {
 	    /* str_buf */
-	    if (FIX2LONG(RSTRING(str)->orig) != RSTRING(str)->len) {
+	    if (RSTRING(str)->aux.capa != RSTRING(str)->len) {
 		REALLOC_N(RSTRING(str)->ptr, char, RSTRING(str)->len + 1);
 	    }
 	}
-	else if (RSTRING(str)->orig) {
-	    rb_str_modify(str);
-	}
-	RSTRING(str)->orig = add;
-	FL_SET(str, STR_NO_ORIG|STR_ASSOC);
-    }
-    else {
-	/* already associated */
-	rb_ary_concat(RSTRING(str)->orig, add);
+	RSTRING(str)->aux.shared = add;
+	FL_UNSET(str, ELTS_SHARED);
+	FL_SET(str, STR_ASSOC);
     }
 }
 
@@ -250,10 +258,10 @@ VALUE
 rb_str_associated(str)
     VALUE str;
 {
-    if (FL_TEST(str, STR_NO_ORIG|STR_ASSOC) != (STR_NO_ORIG|STR_ASSOC)) {
-	return Qfalse;
+    if (FL_TEST(str, STR_ASSOC)) {
+	return RSTRING(str)->aux.shared;
     }
-    return RSTRING(str)->orig;
+    return Qfalse;
 }
 
 static ID id_to_s;
@@ -274,45 +282,53 @@ rb_obj_as_string(obj)
     return str;
 }
 
-VALUE
-rb_str_dup(str)
+static VALUE
+str_copy(str, clone)
     VALUE str;
+    int clone;
 {
     VALUE str2;
     VALUE klass;
+    int flags;
 
     StringValue(str);
-    klass = rb_obj_class(str);
 
-    if (OBJ_FROZEN(str)) str2 = rb_str_new3(str);
-    else if (FL_TEST(str, STR_NO_ORIG)) {
-	str2 = rb_str_new0(klass, RSTRING(str)->ptr, RSTRING(str)->len);
+    if (FL_TEST(str, ELTS_SHARED)) {
+	str2 = rb_str_new3(RSTRING(str)->aux.shared);
     }
-    else if (RSTRING(str)->orig) {
-	str2 = rb_str_new3(RSTRING(str)->orig);
-	RBASIC(str2)->klass = klass;
-	FL_UNSET(str2, FL_TAINT);
-	OBJ_INFECT(str2, str);
+    else if (FL_TEST(str, STR_ASSOC)) {
+	str2 = str_new(RSTRING(str)->ptr, RSTRING(str)->len);
+	RSTRING(str2)->aux.shared = RSTRING(str)->aux.shared;
+    }
+    else if (OBJ_FROZEN(str)) {
+	str2 = rb_str_new3(str);
     }
     else {
 	str2 = rb_str_new3(rb_str_new4(str));
     }
-    if (FL_TEST(str, FL_EXIVAR))
-	rb_copy_generic_ivar(str2, str);
-    OBJ_INFECT(str2, str);
+    flags = FL_TEST(str2, ELTS_SHARED|STR_ASSOC);
+    if (clone) {
+	CLONESETUP(str2, str);
+    }
+    else {
+	DUPSETUP(str2, str);
+    } 
+    if (flags) FL_SET(str2, flags);
     return str2;
 }
 
+VALUE
+rb_str_dup(str)
+    VALUE str;
+{
+    return str_copy(str, Qfalse);
+}
+
 static VALUE
 rb_str_clone(str)
     VALUE str;
 {
-    VALUE clone = rb_str_dup(str);
-    if (FL_TEST(str, STR_NO_ORIG))
-	RSTRING(clone)->orig = RSTRING(str)->orig;
-    CLONESETUP(clone, str);
-
-    return clone;
+    return str_copy(str, Qtrue);
 }
 
 static VALUE rb_str_replace _((VALUE, VALUE));
@@ -446,9 +462,7 @@ str_independent(str)
     if (OBJ_FROZEN(str)) rb_error_frozen("string");
     if (!OBJ_TAINTED(str) && rb_safe_level() >= 4)
 	rb_raise(rb_eSecurityError, "Insecure: can't modify string");
-    if (!RSTRING(str)->orig || FL_TEST(str, STR_NO_ORIG)) return 1;
-    if (RBASIC(str)->flags == 0) abort();
-    if (TYPE(RSTRING(str)->orig) != T_STRING) rb_bug("non string str->orig");
+    if (!FL_TEST(str, ELTS_SHARED)) return 1;
     return 0;
 }
 
@@ -465,7 +479,8 @@ rb_str_modify(str)
     }
     ptr[RSTRING(str)->len] = 0;
     RSTRING(str)->ptr = ptr;
-    RSTRING(str)->orig = 0;
+    RSTRING(str)->aux.capa = RSTRING(str)->len;
+    FL_UNSET(str, ELTS_SHARED|STR_ASSOC);
 }
 
 VALUE
@@ -479,9 +494,9 @@ VALUE
 rb_str_dup_frozen(str)
     VALUE str;
 {
-    if (RSTRING(str)->orig && !FL_TEST(str, STR_NO_ORIG)) {
-	OBJ_FREEZE(RSTRING(str)->orig);
-	return RSTRING(str)->orig;
+    if (FL_TEST(str, ELTS_SHARED)) {
+	OBJ_FREEZE(RSTRING(str)->aux.shared);
+	return RSTRING(str)->aux.shared;
     }
     if (OBJ_FROZEN(str)) return str;
     str = rb_str_dup(str);
@@ -516,21 +531,17 @@ rb_str_buf_cat(str, ptr, len)
 {
     long i, capa, total;
 
-    if (RSTRING(str)->orig == 0) {
-	capa = RSTRING(str)->len;
-	FL_SET(str, STR_NO_ORIG);
-    }
-    else {
-	capa = FIX2LONG(RSTRING(str)->orig);
+    if (FL_TEST(str, ELTS_SHARED)) {
+	rb_str_modify(str);
     }
-
+    capa = RSTRING(str)->aux.capa;
     total = RSTRING(str)->len+len;
     if (capa <= total) {
 	while (total > capa) {
 	    capa = (capa + 1) * 2;
 	}
 	REALLOC_N(RSTRING(str)->ptr, char, capa+1);
-	RSTRING(str)->orig = LONG2FIX(capa);
+	RSTRING(str)->aux.capa = capa;
     }
     memcpy(RSTRING(str)->ptr + RSTRING(str)->len, ptr, len);
     RSTRING(str)->len = total;
@@ -557,8 +568,7 @@ rb_str_cat(str, ptr, len)
 
     rb_str_modify(str);
     if (len > 0) {
-	if (RSTRING(str)->orig == 0 ||
-	    (FL_TEST(str, STR_NO_ORIG) && !FL_TEST(str, STR_ASSOC))) {
+	if (!FL_TEST(str, ELTS_SHARED) && !FL_TEST(str, STR_ASSOC)) {
 	    return rb_str_buf_cat(str, ptr, len);
 	}
 	REALLOC_N(RSTRING(str)->ptr, char, RSTRING(str)->len+len+1);
@@ -589,13 +599,10 @@ rb_str_buf_append(str, str2)
 {
     long i, capa, len;
 
-    if (RSTRING(str)->orig == 0) {
-	capa = RSTRING(str)->len;
-	FL_SET(str, STR_NO_ORIG);
-    }
-    else {
-	capa = FIX2LONG(RSTRING(str)->orig);
+    if (FL_TEST(str, ELTS_SHARED)) {
+	rb_str_modify(str);
     }
+    capa = RSTRING(str)->aux.capa;
 
     len = RSTRING(str)->len+RSTRING(str2)->len;
     if (capa <= len) {
@@ -603,7 +610,7 @@ rb_str_buf_append(str, str2)
 	    capa = (capa + 1) * 2;
 	}
 	REALLOC_N(RSTRING(str)->ptr, char, capa+1);
-	RSTRING(str)->orig = LONG2FIX(capa);
+	RSTRING(str)->aux.capa = capa;
     }
     memcpy(RSTRING(str)->ptr + RSTRING(str)->len,
 	   RSTRING(str2)->ptr, RSTRING(str2)->len);
@@ -623,11 +630,9 @@ rb_str_append(str, str2)
     rb_str_modify(str);
     if (RSTRING(str2)->len > 0) {
 	len = RSTRING(str)->len+RSTRING(str2)->len;
-	if (RSTRING(str)->orig == 0 ||
-	    (FL_TEST(str, STR_NO_ORIG) && !FL_TEST(str, STR_ASSOC))) {
+	if (!FL_TEST(str, ELTS_SHARED) && !FL_TEST(str, STR_ASSOC)) {
 	    rb_str_buf_append(str, str2);
 	    OBJ_INFECT(str, str2);
-	    
 	    return str;
 	}
 	REALLOC_N(RSTRING(str)->ptr, char, len+1);
@@ -810,6 +815,13 @@ rb_str_match2(str)
     return rb_reg_match2(rb_reg_regcomp(str));
 }
 
+static VALUE
+rb_str_match_m(str, re)
+    VALUE str, re;
+{
+    return rb_funcall(re, rb_intern("match"), 1, str);
+}
+
 static long
 rb_str_index(str, sub, offset)
     VALUE str, sub;
@@ -1529,20 +1541,18 @@ str_gsub(argc, argv, str, bang)
 	if (str_independent(str)) {
 	    free(RSTRING(str)->ptr);
 	}
-	else {
-	    RSTRING(str)->orig = 0;
-	}
+	FL_UNSET(str, ELTS_SHARED|STR_ASSOC);
     }
     else {
 	VALUE dup = rb_obj_alloc(rb_obj_class(str));
 
 	OBJ_INFECT(dup, str);
 	str = dup;
-	RSTRING(dup)->orig = 0;
     }
     RSTRING(str)->ptr = buf;
     RSTRING(str)->len = len = bp - buf;
     RSTRING(str)->ptr[len] = '\0';
+    RSTRING(str)->aux.capa = len;
 
     if (tainted) OBJ_TAINT(str);
     return str;
@@ -1573,13 +1583,19 @@ rb_str_replace(str, str2)
     if (str == str2) return str;
 
     StringValue(str2);
-    if (RSTRING(str2)->orig && !FL_TEST(str2, STR_NO_ORIG)) {
+    if (FL_TEST(str2, ELTS_SHARED)) {
 	if (str_independent(str)) {
 	    free(RSTRING(str)->ptr);
 	}
 	RSTRING(str)->len = RSTRING(str2)->len;
 	RSTRING(str)->ptr = RSTRING(str2)->ptr;
-	RSTRING(str)->orig = RSTRING(str2)->orig;
+	if (FL_TEST(str2, ELTS_SHARED|STR_ASSOC)) {
+	    FL_SET(str, RBASIC(str2)->flags & (ELTS_SHARED|STR_ASSOC));
+	    RSTRING(str)->aux.shared = RSTRING(str2)->aux.shared;
+	}
+	else {
+	    RSTRING(str)->aux.capa = RSTRING(str2)->aux.capa;
+	}
     }
     else {
 	rb_str_modify(str);
@@ -3113,6 +3129,7 @@ Init_String()
     rb_define_method(rb_cString, "empty?", rb_str_empty, 0);
     rb_define_method(rb_cString, "=~", rb_str_match, 1);
     rb_define_method(rb_cString, "~", rb_str_match2, 0);
+    rb_define_method(rb_cString, "match", rb_str_match_m, 1);
     rb_define_method(rb_cString, "succ", rb_str_succ, 0);
     rb_define_method(rb_cString, "succ!", rb_str_succ_bang, 0);
     rb_define_method(rb_cString, "next", rb_str_succ, 0);
diff --git a/time.c b/time.c
index 35ef208802..655a49f1fe 100644
--- a/time.c
+++ b/time.c
@@ -72,9 +72,9 @@ time_new_internal(klass, sec, usec)
 	sec += usec / 1000000;
 	usec %= 1000000;
     }
-    if (usec < 0) {		/* usec underflow */
-	sec -= (-usec) / 1000000;
-	usec %= 1000000;
+    while (usec < 0) {		/* usec underflow */
+	sec--;
+	usec += 1000000;
     }
 #ifndef NEGATIVE_TIME_T
     if (sec < 0 || (sec == 0 && usec < 0))
@@ -643,7 +643,13 @@ time_cmp(time1, time2)
 	return INT2FIX(-1);
     }
     i = NUM2LONG(time2);
-    if (tobj1->tv.tv_sec == i) return INT2FIX(0);
+    if (tobj1->tv.tv_sec == i) {
+	if (tobj1->tv.tv_usec == 0)
+	    return INT2FIX(0);
+	if (tobj1->tv.tv_usec > 0)
+	    return INT2FIX(1);
+	return INT2FIX(-1);
+    }
     if (tobj1->tv.tv_sec > i) return INT2FIX(1);
     return INT2FIX(-1);
 }
@@ -760,6 +766,35 @@ time_gmtime(time)
 }
 
 static VALUE
+time_dup(time)
+    VALUE time;
+{
+    VALUE clone;
+    struct time_object *tobj, *tclone;
+
+    GetTimeval(time, tobj);
+    clone = Data_Make_Struct(0, struct time_object, 0, free, tclone);
+    DUPSETUP(clone, time);
+    MEMCPY(tclone, tobj, struct time_object, 1);
+
+    return clone;
+}
+
+static VALUE
+time_getlocaltime(time)
+    VALUE time;
+{
+    return time_localtime(time_dup(time));
+}
+
+static VALUE
+time_getgmtime(time)
+    VALUE time;
+{
+    return time_gmtime(time_dup(time));
+}
+
+static VALUE
 time_get_tm(time, gmt)
     VALUE time;
     int gmt;
@@ -1071,7 +1106,7 @@ rb_strftime(buf, format, time)
 	 * if the buffer is 1024 times bigger than the length of the
 	 * format string, it's not failing for lack of room.
 	 */
-	if (len > 0 || len >= 1024 * flen) return len;
+	if (len > 0 || size >= 1024 * flen) return len;
 	free(*buf);
     }
     /* not reached */
@@ -1109,7 +1144,10 @@ time_strftime(time, format)
 	    p += strlen(p) + 1;
 	    if (p <= pe)
 		rb_str_cat(str, "\0", 1);
-	    if (len > SMALLBUF) free(buf);
+	    if (buf != buffer) {
+		free(buf);
+		buf = buffer;
+	    }
 	}
 	return str;
     }
@@ -1231,10 +1269,15 @@ Init_Time()
     rb_define_method(rb_cTime, "eql?", time_eql, 1);
     rb_define_method(rb_cTime, "hash", time_hash, 0);
     rb_define_method(rb_cTime, "clone", time_clone, 0);
+    rb_define_method(rb_cTime, "dup", time_dup, 0);
 
     rb_define_method(rb_cTime, "localtime", time_localtime, 0);
     rb_define_method(rb_cTime, "gmtime", time_gmtime, 0);
     rb_define_method(rb_cTime, "utc", time_gmtime, 0);
+    rb_define_method(rb_cTime, "getlocal", time_getlocaltime, 0);
+    rb_define_method(rb_cTime, "getgm", time_getgmtime, 0);
+    rb_define_method(rb_cTime, "getutc", time_getgmtime, 0);
+
     rb_define_method(rb_cTime, "ctime", time_asctime, 0);
     rb_define_method(rb_cTime, "asctime", time_asctime, 0);
     rb_define_method(rb_cTime, "to_s", time_to_s, 0);
diff --git a/util.c b/util.c
index bec54f4237..26a35ed398 100644
--- a/util.c
+++ b/util.c
@@ -384,31 +384,25 @@ __crt0_glob_function(char *path)
 
 /* mm.c */
 
-static int mmkind, mmsize, high, low;
-
 #define A ((int*)a)
 #define B ((int*)b)
 #define C ((int*)c)
 #define D ((int*)d)
 
-static void mmprepare(base, size) void *base; int size;
-{
-#ifdef DEBUG
- if (sizeof(int) != 4) die("sizeof(int) != 4");
- if (size <= 0) die("mmsize <= 0");
-#endif
+#define mmprepare(base, size) do {\
+ if (((long)base & (0x3)) == 0)\
+   if (size >= 16) mmkind = 1;\
+   else            mmkind = 0;\
+ else              mmkind = -1;\
+ high = (size & (~0xf));\
+ low  = (size &  0x0c);\
+} while (0)\
 
- if (((long)base & (4-1)) == 0 && ((long)base & (4-1)) == 0)
-   if (size >= 16) mmkind = 1;
-   else            mmkind = 0;
- else              mmkind = -1;
- 
- mmsize = size;
- high = (size & (-16));
- low  = (size & 0x0c);
-}
+#define mmarg mmkind, size, high, low
 
-static void mmswap(a, b) register char *a, *b;
+static void mmswap_(a, b, mmarg)
+    register char *a, *b;
+    int mmarg;
 {
  register int s;
  if (a == b) return;
@@ -427,12 +421,15 @@ static void mmswap(a, b) register char *a, *b;
        if (low == 12) {s = A[2]; A[2] = B[2]; B[2] = s;}}}
  }
  else {
-   register char *t = a + mmsize;
+   register char *t = a + size;
    do {s = *a; *a++ = *b; *b++ = s;} while (a < t);
  }
 }
+#define mmswap(a,b) mmswap_((a),(b),mmarg)
 
-static void mmrot3(a, b, c) register char *a, *b, *c;
+static void mmrot3_(a, b, c, mmarg)
+    register char *a, *b, *c;
+    int mmarg;
 {
  register int s;
  if (mmkind >= 0) {
@@ -450,10 +447,11 @@ static void mmrot3(a, b, c) register char *a, *b, *c;
        if (low == 12) {s = A[2]; A[2] = B[2]; B[2] = C[2]; C[2] = s;}}}
  }
  else {
-   register char *t = a + mmsize;
+   register char *t = a + size;
    do {s = *a; *a++ = *b; *b++ = *c; *c++ = s;} while (a < t);
  }
 }
+#define mmrot3(a,b,c) mmrot3_((a),(b),(c),mmarg)
 
 /* qs6.c */
 /*****************************************************/
@@ -472,14 +470,19 @@ typedef struct { char *LL, *RR; } stack_node; /* Stack structure for L,l,R,r */
                        ((*cmp)(b,c)<0 ? b : ((*cmp)(a,c)<0 ? c : a)) : \
                        ((*cmp)(b,c)>0 ? b : ((*cmp)(a,c)<0 ? a : c)))
 
-void ruby_qsort (base, nel, size, cmp) void* base; int nel; int size; int (*cmp)();
+void ruby_qsort (base, nel, size, cmp)
+     void* base;
+     const int nel;
+     const int size;
+     int (*cmp)();
 {
   register char *l, *r, *m;          	/* l,r:left,right group   m:median point */
   register int  t, eq_l, eq_r;       	/* eq_l: all items in left group are equal to S */
   char *L = base;                    	/* left end of curren region */
-  char *R = (char*)base + size*(nel-1); 	/* right end of current region */
-  int  chklim = 63;                      /* threshold of ordering element check */
-  stack_node stack[32], *top = stack;    /* 32 is enough for 32bit CPU */
+  char *R = (char*)base + size*(nel-1); /* right end of current region */
+  int  chklim = 63;                     /* threshold of ordering element check */
+  stack_node stack[32], *top = stack;   /* 32 is enough for 32bit CPU */
+  int mmkind, high, low;
 
   if (nel <= 1) return;        /* need not to sort */
   mmprepare(base, size);
@@ -491,7 +494,9 @@ void ruby_qsort (base, nel, size, cmp) void* base; int nel; int size; int (*cmp)
 
   for (;;) {
     start:
-    if (L + size == R) {if ((*cmp)(L,R) > 0) mmswap(L,R); goto nxt;}/* 2 elements */
+    if (L + size == R) {       /* 2 elements */
+      if ((*cmp)(L,R) > 0) mmswap(L,R); goto nxt;
+    }
 
     l = L; r = R;
     t = (r - l + size) / size;  /* number of elements */
@@ -559,7 +564,7 @@ void ruby_qsort (base, nel, size, cmp) void* base; int nel; int size; int (*cmp)
     if ((t = (*cmp)(m,r)) < 0)  {goto loopA;}                /*5-5-7*/
     if (t > 0) {mmswap(l,r); goto loopB;}                    /*5-5-3*/
 
-    /* deteming splitting type in case 5-5-5 */              /*5-5-5*/
+    /* determining splitting type in case 5-5-5 */           /*5-5-5*/
     for (;;) {
       if ((l += size) == r)      goto nxt;                   /*5-5-5*/
       if (l == m) continue;
diff --git a/version.h b/version.h
index a53780acb2..fb712da798 100644
--- a/version.h
+++ b/version.h
@@ -1,4 +1,4 @@
 #define RUBY_VERSION "1.7.2"
-#define RUBY_RELEASE_DATE "2001-12-09"
+#define RUBY_RELEASE_DATE "2001-12-10"
 #define RUBY_VERSION_CODE 172
-#define RUBY_RELEASE_CODE 20011209
+#define RUBY_RELEASE_CODE 20011210