* file.c (rb_file_s_extname): first dot is not an extension name.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@16439 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Sat May 17 11:29:11 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* file.c (rb_file_s_extname): first dot is not an extension name.
+
 Sat May 17 03:21:29 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* array.c (rb_ary_sort_bang): stop memory leak.  [ruby-dev:34726]

file.c

@@ -3104,7 +3104,7 @@ rb_file_s_extname(VALUE klass, VALUE fname)
     if (!p)
 	p = name;
     else
-	p++;
+	name = ++p;
 
     e = 0;
     while (*p) {
@@ -3134,7 +3134,7 @@ rb_file_s_extname(VALUE klass, VALUE fname)
 	    break;
 	p = CharNext(p);
     }
-    if (!e || e+1 == p)	/* no dot, or the only dot is first or end? */
+    if (!e || e == name || e+1 == p)	/* no dot, or the only dot is first or end? */
 	return rb_str_new(0, 0);
     extname = rb_str_new(e, p - e);	/* keep the dot, too! */
     rb_enc_copy(extname, fname);

test/ruby/test_file_exhaustive.rb

@@ -411,6 +411,17 @@ class TestFileExhaustive < Test::Unit::TestCase
   def test_extname
     assert(".test", File.extname(@file))
     assert_equal("", File.extname("foo"))
+    assert_equal("", File.extname("/foo"))
+    assert_equal("", File.extname(".foo"))
+    assert_equal("", File.extname("/.foo"))
+    assert_equal("", File.extname("bar/.foo"))
+    assert_equal("", File.extname("/bar/.foo"))
+    assert_equal(".ext", File.extname("foo.ext"))
+    assert_equal(".ext", File.extname("/foo.ext"))
+    assert_equal(".ext", File.extname(".foo.ext"))
+    assert_equal(".ext", File.extname("/.foo.ext"))
+    assert_equal(".ext", File.extname("bar/.foo.ext"))
+    assert_equal(".ext", File.extname("/bar/.foo.ext"))
     assert_equal("", File.extname(""))
     if /cygwin|mingw|mswin|bccwin/ =~ RUBY_PLATFORM
       assert_equal("", File.extname("foo "))