fix windows, add another test

Author: hauntsaninja

mypy/modulefinder.py

@@ -476,6 +476,7 @@ def find_modules_recursive(self, module: str) -> List[BuildSource]:
 
 
 def matches_ignore_pattern(path: str, pattern: str) -> bool:
+    path = os.path.splitdrive(path)[1]
     path_components = path.split(os.sep)
     pattern_components = pattern.split(os.sep)
     return all(

mypy/test/test_find_sources.py

@@ -268,7 +268,7 @@ def test_find_sources_ignore_path(self) -> None:
             "/pkg/a2/b/f.py",
         }
 
-        options.ignore_path = ["/pkg/a", "2", "1", "pk", "kg", "g.py", "bc"]
+        options.ignore_path = ["/pkg/a", "2", "1", "pk", "kg", "g.py", "bc", "/b"]
         finder = SourceFinder(FakeFSCache(files), options)
         assert len(find_sources(finder, "/")) == len(files)
 
@@ -287,3 +287,17 @@ def test_find_sources_ignore_path(self) -> None:
             ("a2.b.c.d.e", "/pkg"),
             ("e", "/pkg/a1/b/c/d"),
         ]
+
+        files = {
+            "pkg/a1/b/c/d/e.py",
+            "pkg/a1/b/f.py",
+            "pkg/a2/__init__.py",
+            "pkg/a2/b/c/d/e.py",
+            "pkg/a2/b/f.py",
+        }
+
+        options.ignore_path = [
+            "/pkg/a", "2", "1", "pk", "kg", "g.py", "bc", "/b", "/pkg/a1", "/pkg/a2"
+        ]
+        finder = SourceFinder(FakeFSCache(files), options)
+        assert len(find_sources(finder, "/")) == len(files)