Fix infinite recursion collection bug with pytest_ignore_collect hook

changelog/3771.bugfix.rst

@@ -0,0 +1 @@
+Fix infinite recursion during collection if a ``pytest_ignore_collect`` returns ``False`` instead of ``None``.

src/_pytest/python.py

@@ -561,7 +561,7 @@ def __init__(self, fspath, parent=None, config=None, session=None, nodeid=None):
     def _recurse(self, path):
         ihook = self.gethookproxy(path.dirpath())
         if ihook.pytest_ignore_collect(path=path, config=self.config):
-            return
+            return False
         for pat in self._norecursepatterns:
             if path.check(fnmatch=pat):
                 return False
@@ -594,9 +594,12 @@ def isinitpath(self, path):
         return path in self.session._initialpaths
 
     def collect(self):
-        path = self.fspath.dirpath()
+        this_path = self.fspath.dirpath()
         pkg_prefix = None
-        for path in path.visit(fil=lambda x: 1, rec=self._recurse, bf=True, sort=True):
+        for path in this_path.visit(rec=self._recurse, bf=True, sort=True):
+            # we will visit our own __init__.py file, in which case we skip it
+            if path.basename == "__init__.py" and path.dirpath() == this_path:
+                continue
             if pkg_prefix and pkg_prefix in path.parts():
                 continue
             for x in self._collectfile(path):

testing/example_scripts/collect/package_infinite_recursion/conftest.py

@@ -0,0 +1,2 @@
+def pytest_ignore_collect(path):
+    return False

testing/example_scripts/collect/package_infinite_recursion/tests/test_basic.py

@@ -0,0 +1,2 @@
+def test():
+    pass

testing/python/collect.py

@@ -1577,3 +1577,9 @@ def test_real():
     )
     result = testdir.runpytest("--keep-duplicates", a.strpath, a.strpath)
     result.stdout.fnmatch_lines(["*collected 2 item*"])
+
+
+def test_package_collection_infinite_recursion(testdir):
+    testdir.copy_example("collect/package_infinite_recursion")
+    result = testdir.runpytest()
+    result.stdout.fnmatch_lines("*1 passed*")