diff --git a/ChangeLog b/ChangeLog
index 0d19f88884..09004a09a7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Jun 29 18:55:55 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* dln.c (dln_find_1): fix for files with dots.  [ruby-dev:38588]
+
 Mon Jun 29 17:14:31 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* file.c (file_expand_path): should copy original encoding.
diff --git a/dln.c b/dln.c
index bf5408105a..484dab5d1d 100644
--- a/dln.c
+++ b/dln.c
@@ -1519,7 +1519,12 @@ dln_find_1(const char *fname, const char *path, char *fbuf, size_t size,
     struct stat st;
     size_t i, fspace;
 #ifdef DOSISH
-    int is_abs = 0, has_path = 0, has_ext = 0;
+    static const char extension[][5] = {
+	".exe", ".com", ".cmd", ".bat",
+    };
+    size_t j;
+    int is_abs = 0, has_path = 0;
+    const char *ext = 0;
     const char *p = fname;
 #endif
 
@@ -1546,23 +1551,31 @@ dln_find_1(const char *fname, const char *path, char *fbuf, size_t size,
 	switch (*p) {
 	  case '/': case '\\':
 	    has_path = 1;
-	    has_ext = 0;
+	    ext = 0;
 	    p++;
 	    break;
 	  case '.':
-	    has_ext = 1;
+	    ext = p;
 	    p++;
 	    break;
 	  default:
 	    p = CharNext(p);
 	}
     }
+    if (ext) {
+	for (j = 0; STRCASECMP(ext, extension[j]); j++) {
+	    if (j == sizeof(extension) / sizeof(extension[0])) {
+		ext = 0;
+		break;
+	    }
+	}
+    }
     ep = bp = 0;
     if (!exe_flag) {
 	RETURN_IF(is_abs);
     }
     else if (has_path) {
-	RETURN_IF(has_ext);
+	RETURN_IF(ext);
 	i = p - fname;
 	if (i + 1 > size) goto toolong;
 	fspace = size - i - 1;
@@ -1646,15 +1659,7 @@ dln_find_1(const char *fname, const char *path, char *fbuf, size_t size,
 	memcpy(bp, fname, i + 1);
 
 #if defined(DOSISH)
-	if (exe_flag && !has_ext) {
-	    static const char extension[][5] = {
-#if defined(__EMX__) || defined(_WIN32)
-		".exe", ".com", ".cmd", ".bat",
-/* end of __EMX__ or _WIN32 */
-#endif
-	    };
-	    size_t j;
-
+	if (exe_flag && !ext) {
 	  needs_extension:
 	    for (j = 0; j < sizeof(extension) / sizeof(extension[0]); j++) {
 		if (fspace < strlen(extension[j])) {
diff --git a/test/ruby/test_system.rb b/test/ruby/test_system.rb
index be441c95fe..903918812d 100644
--- a/test/ruby/test_system.rb
+++ b/test/ruby/test_system.rb
@@ -60,6 +60,28 @@ class TestSystem < Test::Unit::TestCase
 
       File.unlink tmpfilename or `/bin/rm -f "#{tmpfilename}"`
       File.unlink "#{tmpfilename}.bak" or `/bin/rm -f "#{tmpfilename}.bak"`
+
+      if /mswin|mingw/ =~ RUBY_PLATFORM
+        testname = '[ruby-dev:38588]'
+        batch = "batch_tmp.#{$$}"
+        tmpfilename = "#{tmpdir}/#{batch}.bat"
+        open(tmpfilename, "wb") {|f| f.print "\r\n"}
+        assert(system(tmpfilename), testname)
+        assert(system("#{tmpdir}/#{batch}"), testname)
+        assert(system(tmpfilename, "1"), testname)
+        assert(system("#{tmpdir}/#{batch}", "1"), testname)
+        begin
+          path = ENV["PATH"]
+          ENV["PATH"] = "#{tmpdir.tr(File::SEPARATOR, File::ALT_SEPARATOR)}#{File::PATH_SEPARATOR + path if path}"
+          assert(system("#{batch}.bat"), testname)
+          assert(system(batch), testname)
+          assert(system("#{batch}.bat", "1"), testname)
+          assert(system(batch, "1"), testname)
+        ensure
+          ENV["PATH"] = path
+        end
+        File.unlink tmpfilename
+      end
     }
   end