Don't test lexer classes from arbitrary plugins.

2 files changed, 6 insertions, 5 deletions

diff --git a/pygments/lexers/__init__.py b/pygments/lexers/__init__.py
index 369b7cc4..80545b6c 100644
--- a/pygments/lexers/__init__.py
+++ b/pygments/lexers/__init__.py
@@ -166,15 +166,16 @@ def get_lexer_for_mimetype(_mime, **options):
     raise ClassNotFound('no lexer for mimetype %r found' % _mime)
 
 
-def _iter_lexerclasses():
+def _iter_lexerclasses(plugins=True):
     """Return an iterator over all lexer classes."""
     for key in sorted(LEXERS):
         module_name, name = LEXERS[key][:2]
         if name not in _lexer_cache:
             _load_lexers(module_name)
         yield _lexer_cache[name]
-    for lexer in find_plugin_lexers():
-        yield lexer
+    if plugins:
+        for lexer in find_plugin_lexers():
+            yield lexer
 
 
 def guess_lexer_for_filename(_fn, _text, **options):
diff --git a/tests/test_basic_api.py b/tests/test_basic_api.py
index e6b9b325..6069f97c 100644
--- a/tests/test_basic_api.py
+++ b/tests/test_basic_api.py
@@ -80,7 +80,7 @@ def test_lexer_classes():
         assert txt == test_content, "%s lexer roundtrip failed: %r != %r" % \
             (cls.name, test_content, txt)
 
-    for lexer in lexers._iter_lexerclasses():
+    for lexer in lexers._iter_lexerclasses(plugins=False):
         yield verify, lexer
 
 
@@ -110,7 +110,7 @@ def test_lexer_options():
             inst = cls(ensurenl=False, stripall=True)
             ensure(inst.get_tokens('a\nb\n\n'), 'a\nb')
 
-    for lexer in lexers._iter_lexerclasses():
+    for lexer in lexers._iter_lexerclasses(plugins=False):
         if lexer.__name__ == 'RawTokenLexer':
             # this one is special
             continue