diff --git a/ChangeLog b/ChangeLog
index 73e6162862..fb25146591 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Jun 15 19:19:21 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/iconv/iconv.c (iconv_convert): check upper bound.  a patch from
+	  Daniel Luz at [ruby-Bugs-17910].
+
 Sun Jun 15 19:07:41 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in (ftruncate): check if available.
diff --git a/ext/iconv/iconv.c b/ext/iconv/iconv.c
index 918dd51630..484abd203d 100644
--- a/ext/iconv/iconv.c
+++ b/ext/iconv/iconv.c
@@ -423,8 +423,11 @@ iconv_convert
 	    length = 0;
 	else if ((length -= start) < 0)
 	    length = 0;
-	else
+	else {
 	    inptr += start;
+	    if (length > slen)
+		length = slen;
+	}
     }
     instart = inptr;
     inlen = length;
diff --git a/version.h b/version.h
index f5cf4f9394..e0f045aaf0 100644
--- a/version.h
+++ b/version.h
@@ -2,7 +2,7 @@
 #define RUBY_RELEASE_DATE "2008-06-15"
 #define RUBY_VERSION_CODE 185
 #define RUBY_RELEASE_CODE 20080615
-#define RUBY_PATCHLEVEL 177
+#define RUBY_PATCHLEVEL 178
 
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 8