diff --git a/ChangeLog b/ChangeLog
index 3060787ead..0f32a33b2d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jul  8 00:22:58 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (rb_str_succ): limit carrying in an alphanumeric region if
+	  exists.  [ruby-dev:35094]
+
 Mon Jul  7 20:39:28 2008  Masaki Suketa  <masaki.suketa@nifty.ne.jp>
 
 	* ext/win32ole/win32ole.c(Init_win32ole): add
diff --git a/string.c b/string.c
index 983f3e682a..8c1cf0d831 100644
--- a/string.c
+++ b/string.c
@@ -2535,13 +2535,16 @@ rb_str_succ(VALUE orig)
         enum neighbor_char neighbor;
 	if ((l = rb_enc_precise_mbclen(s, e, enc)) <= 0) continue;
         neighbor = enc_succ_alnum_char(s, l, enc, carry);
-        if (neighbor == NEIGHBOR_NOT_CHAR)
-            continue;
-        if (neighbor == NEIGHBOR_FOUND)
+        if (neighbor == NEIGHBOR_NOT_CHAR) {
+	    if (c == -1) continue;
+            s++;
+	}
+        else if (neighbor == NEIGHBOR_FOUND)
             return str;
         c = 1;
         carry_pos = s - sbeg;
         carry_len = l;
+        if (neighbor == NEIGHBOR_NOT_CHAR) break;
     }
     if (c == -1) {		/* str contains no alnum */
 	s = e;
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index 869e31b641..29bc2672ec 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -1222,6 +1222,7 @@ class TestString < Test::Unit::TestCase
     assert_equal(S("124"),  S("123").succ)
     assert_equal(S("1000"), S("999").succ)
 
+    assert_equal(S("No.10"), S("No.9").succ)
     assert_equal(S("2000aaa"),  S("1999zzz").succ)
     assert_equal(S("AAAAA000"), S("ZZZZ999").succ)
     assert_equal(S("*+"), S("**").succ)
@@ -1269,6 +1270,10 @@ class TestString < Test::Unit::TestCase
     assert_equal(S("*+"), a.succ!)
     assert_equal(S("*+"), a)
 
+    a = S("No.9")
+    assert_equal(S("No.10"), a.succ!)
+    assert_equal(S("No.10"), a)
+
     assert_equal("aaaaaaaaaaaa", "zzzzzzzzzzz".succ!)
     assert_equal("aaaaaaaaaaaaaaaaaaaaaaaa", "zzzzzzzzzzzzzzzzzzzzzzz".succ!)
   end