diff --git a/ChangeLog b/ChangeLog
index 319fb44ad6..54fdee5c57 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+Tue Sep  2 00:41:27 2003  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/iconv/iconv.c (map_charset): use lower case keys.
+
+	* ext/iconv/iconv.c (iconv_fail): just yield error and return the
+	  result if a block is given.
+
+	* ext/iconv/iconv.c (iconv_convert): yield error and append the
+	  result if a block is given.
+
+	* ext/iconv/charset_alias.rb (charset_alias): optional third
+	  argument.
+
+	* ext/iconv/charset_alias.rb (charset_alias): use CP932 instead of
+	  SHIFT_JIS on cygwin.
+
 Mon Sep  1 18:34:25 2003  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (rb_eval): make tail recursion in ELSE clause of
diff --git a/ext/iconv/charset_alias.rb b/ext/iconv/charset_alias.rb
index 20a7f6406a..48f0fae5f9 100644
--- a/ext/iconv/charset_alias.rb
+++ b/ext/iconv/charset_alias.rb
@@ -1,16 +1,16 @@
 #! /usr/bin/ruby
 require 'rbconfig'
 
-# http://www.ctan.org/tex-archive/macros/texinfo/texinfo/intl/config.charset'
+# http://www.ctan.org/tex-archive/macros/texinfo/texinfo/intl/config.charset
 # Fri, 30 May 2003 00:09:00 GMT'
 
 OS = Config::CONFIG["target"]
 SHELL = Config::CONFIG['SHELL']
 
-def charset_alias(config_charset, mapfile)
+def charset_alias(config_charset, mapfile, target = OS)
   map = {}
   comments = []
-  IO.foreach("|#{SHELL} #{config_charset} #{OS}") do |list|
+  IO.foreach("|#{SHELL} #{config_charset} #{target}") do |list|
     next comments << list if /^\#/ =~ list
     next unless /^(\S+)\s+(\S+)$/ =~ list
     sys, can = $1, $2
@@ -18,9 +18,12 @@ def charset_alias(config_charset, mapfile)
     next if can.downcase! and sys == can
     map[can] = sys
   end
-  case OS
+  case target
   when /linux|-gnu/
     map.delete('ascii')
+  when /cygwin/
+    # get rid of tilde/yen problem.
+    map['shift_jis'] = 'cp932'
   end
   open(mapfile, "w") do |f|
     f.puts("require 'iconv.so'")
@@ -32,5 +35,5 @@ def charset_alias(config_charset, mapfile)
   end
 end
 
-ARGV.size == 2 or abort "usage: #$0 config.status map.rb"
+(2..3) === ARGV.size or abort "usage: #$0 config.status map.rb [target]"
 charset_alias(*ARGV)
diff --git a/ext/iconv/iconv.c b/ext/iconv/iconv.c
index cbb89dca48..b15332e386 100644
--- a/ext/iconv/iconv.c
+++ b/ext/iconv/iconv.c
@@ -59,6 +59,7 @@ static VALUE rb_eIconvOutOfRange;
 static ID rb_inserter;
 
 static ID rb_success, rb_failed, rb_mesg;
+static VALUE iconv_fail _((VALUE error, VALUE success, VALUE failed, struct iconv_env_t* env));
 static VALUE iconv_failure_initialize _((VALUE error, VALUE success, VALUE failed, struct iconv_env_t* env));
 static VALUE iconv_failure_success _((VALUE self));
 static VALUE iconv_failure_failed _((VALUE self));
@@ -108,13 +109,17 @@ map_charset
 {
     VALUE val = *code;
 
-    StringValuePtr(val);
     if (RHASH(charset_map)->tbl && RHASH(charset_map)->tbl->num_entries) {
+	val = rb_funcall2(val, rb_intern("downcase"), 0, 0);
+	StringValuePtr(val);
 	if (st_lookup(RHASH(charset_map)->tbl, val, &val)) {
 	    StringValuePtr(val);
 	    *code = val;
 	}
     }
+    else {
+	StringValuePtr(val);
+    }
     return RSTRING(val)->ptr;
 }
 
@@ -231,9 +236,6 @@ iconv_try
     return Qfalse;
 }
 
-#define iconv_fail(error, success, failed, env) \
-	rb_exc_raise(iconv_failure_initialize(error, success, failed, env))
-
 #define FAILED_MAXLEN 16
 
 static VALUE
@@ -270,6 +272,21 @@ iconv_failure_initialize
     return error;
 }
 
+static VALUE
+iconv_fail
+#ifdef HAVE_PROTOTYPES
+    (VALUE error, VALUE success, VALUE failed, struct iconv_env_t* env)
+#else /* HAVE_PROTOTYPES */
+    (error, success, failed, env)
+    VALUE error, success, failed;
+    struct iconv_env_t *env;
+#endif /* HAVE_PROTOTYPES */
+{
+    error = iconv_failure_initialize(error, success, failed, env);
+    if (!rb_block_given_p()) rb_exc_raise(error);
+    return rb_yield(error);
+}
+
 static VALUE
 rb_str_derive
 #ifdef HAVE_PROTOTYPES
@@ -327,8 +344,17 @@ iconv_convert
 	outptr = buffer;
 	outlen = sizeof(buffer);
 	error = iconv_try(cd, &inptr, &inlen, &outptr, &outlen);
-	if (error)
-	    iconv_fail(error, Qnil, Qnil, env);
+	if (error) {
+	    unsigned int i;
+	    str = iconv_fail(error, Qnil, Qnil, env);
+	    if (FIXNUM_P(str) && (i = FIX2INT(str)) <= 0xff) {
+		char c = i;
+		str = rb_str_new(&c, 1);
+	    }
+	    else if (!NIL_P(str)) {
+		StringValue(str);
+	    }
+	}
 
 	inptr = NULL;
 	length = 0;
@@ -395,7 +421,7 @@ iconv_convert
 	    if (!ret)
 		ret = rb_str_derive(str, instart, inptr - instart);
 	    str = rb_str_derive(str, inptr, inlen);
-	    iconv_fail(error, ret, str, env);
+	    rb_str_concat(str, iconv_fail(error, ret, str, env));
 	}
     } while (inlen > 0);