2 files changed, 8 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index cb0d906db0..4af7f3e423 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Sep  7 17:13:53 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* io.c (io_encname_bom_p): removed magic number.
+
 Mon Sep  7 12:26:04 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* lib/irb/inspector.rb (IRB::INSPECTORS.def_inspector): support
diff --git a/io.c b/io.c
index 3391bea4d0..31a86da6b9 100644
--- a/io.c
+++ b/io.c
@@ -3938,11 +3938,13 @@ rb_io_fmode_modestr(int fmode)
 static int
 io_encname_bom_p(const char *name, long len)
 {
+    static const char bom_prefix[] = "bom|utf-";
+    enum {bom_prefix_len = (int)sizeof(bom_prefix) - 1};
     if (!len) {
 	const char *p = strchr(name, ':');
-	len = p ? p - name : strlen(name);
+	len = p ? (long)(p - name) : (long)strlen(name);
     }
-    return len > 8 && STRNCASECMP(name, "bom|utf-", 8) == 0;
+    return len > bom_prefix_len && STRNCASECMP(name, bom_prefix, bom_prefix_len) == 0;
 }
 
 int