* string.c (str_utf8_nth): fixed overrun. [ruby-core:26787]




git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25830 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 10 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index a7e0c62683..7cd75bf441 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Nov 18 08:41:42 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (str_utf8_nth): fixed overrun.  [ruby-core:26787]
+
 Wed Nov 18 07:51:01 2009  Tanaka Akira  <akr@fsij.org>
 
 	* io.c (parse_mode_enc): fix invalid access.
diff --git a/string.c b/string.c
index 1cd5e7fbe4..f923b5f168 100644
--- a/string.c
+++ b/string.c
@@ -1483,6 +1483,7 @@ str_utf8_nth(const char *p, const char *e, long nth)
 	} while (s < t && (int)sizeof(VALUE) <= nth);
 	p = (char *)s;
     }
+    if (p > e) return 0;
     while (p < e) {
 	if (is_utf8_lead_byte(*p)) {
 	    if (nth == 0) break;
diff --git a/test/ruby/test_m17n.rb b/test/ruby/test_m17n.rb
index 1fa6d51288..e5c0acb034 100644
--- a/test/ruby/test_m17n.rb
+++ b/test/ruby/test_m17n.rb
@@ -867,6 +867,11 @@ class TestM17N < Test::Unit::TestCase
     assert_equal(nil, u("\xc2\xa1\xc2\xa2\xc2\xa3")[u("\xa1\xc2")])
     assert_raise(Encoding::CompatibilityError) { u("\xc2\xa1\xc2\xa2\xc2\xa3")[a("\xa1\xc2")] }
     assert_nil(e("\xa1\xa2\xa3\xa4")[e("\xa2\xa3")])
+
+    bug2379 = '[ruby-core:26787]'
+    assert_equal("\u{439}", "\u{439}"[0, 30], bug2379)
+    assert_equal("\u{439}", "a\u{439}"[1, 30], bug2379)
+    assert_equal("\u{439}", "a\u{439}bcdefghijklmnop"[1, 1][0, 1], bug2379)
   end
 
   def test_aset