modeline: work for the first N lines and add a test to keep it that way

2 files changed, 31 insertions, 4 deletions

diff --git a/pygments/modeline.py b/pygments/modeline.py
index 2200f1cf..43c1784f 100644
--- a/pygments/modeline.py
+++ b/pygments/modeline.py
@@ -35,9 +35,10 @@ def get_filetype_from_buffer(buf, max_lines=5):
         ret = get_filetype_from_line(l)
         if ret:
             return ret
-    for l in lines[max_lines:-1:-1]:
-        ret = get_filetype_from_line(l)
-        if ret:
-            return ret
+    for i in range(max_lines, -1, -1):
+        if i < len(lines):
+            ret = get_filetype_from_line(lines[i])
+            if ret:
+                return ret
 
     return None
diff --git a/tests/test_modeline.py b/tests/test_modeline.py
new file mode 100644
index 00000000..d3a0c915
--- /dev/null
+++ b/tests/test_modeline.py
@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+"""
+    Tests for the vim modeline feature
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    :copyright: Copyright 2006-2015 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+from __future__ import print_function
+
+from pygments import modeline
+
+
+def test_lexer_classes():
+    def verify(buf):
+        assert modeline.get_filetype_from_buffer(buf) == 'python'
+
+    for buf in [
+            'vi: ft=python' + '\n' * 8,
+            'vi: ft=python' + '\n' * 8,
+            '\n\n\n\nvi=8: syntax=python' + '\n' * 8,
+            '\n' * 8 + 'ex: filetype=python',
+            '\n' * 8 + 'vim: some,other,syn=python\n\n\n\n'
+    ]:
+        yield verify, buf