From 8e7407cb154d8966f0f1b42847375012e02c2be9 Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Mon, 19 Oct 2020 00:52:03 -0700
Subject: [PATCH 1/4] add a test

---
 test-data/unit/cmdline.test | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/test-data/unit/cmdline.test b/test-data/unit/cmdline.test
index 9d74bdc9a1be..c731cd64dcc2 100644
--- a/test-data/unit/cmdline.test
+++ b/test-data/unit/cmdline.test
@@ -791,6 +791,17 @@ def bar(a: int, b: int) -> str:
 [out]
 src/anamespace/foo/bar.py:2: error: Incompatible return value type (got "int", expected "str")
 
+[case testNestedPEP420Packages]
+# cmd: mypy -p bottles --namespace-packages
+[file bottles/jars/secret/glitter.py]
+x: str = 0
+[file bottles/jars/sprinkle.py]
+from bottles.jars.secret.glitter import x
+x + 1
+[out]
+bottles/jars/secret/glitter.py:1: error: Incompatible types in assignment (expression has type "int", variable has type "str")
+bottles/jars/sprinkle.py:2: error: Unsupported operand types for + ("str" and "int")
+
 [case testFollowImportStubs1]
 # cmd: mypy main.py
 [file mypy.ini]

From 5a0c2fb3d69927504444ec51901ab83ad35279ae Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Mon, 19 Oct 2020 10:52:17 -0700
Subject: [PATCH 2/4] modulefinder: make -p handle namespace packages correctly

Fixes part of #5759
The other part is passing files arguments, which we make steps towards
in #9614
---
 mypy/modulefinder.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mypy/modulefinder.py b/mypy/modulefinder.py
index c5109fa53f3d..5dc5689915bc 100644
--- a/mypy/modulefinder.py
+++ b/mypy/modulefinder.py
@@ -387,13 +387,13 @@ def find_modules_recursive(self, module: str) -> List[BuildSource]:
                     if mod not in hits:
                         hits.add(mod)
                         result += self.find_modules_recursive(module + '.' + mod)
-        elif os.path.isdir(module_path) and module in self.ns_packages:
-            # Even more subtler: handle recursive decent into PEP 420
+        elif os.path.isdir(module_path) and any(module.startswith(p) for p in self.ns_packages):
+            # Even subtler: handle recursive decent into PEP 420
             # namespace packages that are explicitly listed on the command
             # line with -p/--packages.
             for item in sorted(self.fscache.listdir(module_path)):
-                if os.path.isdir(os.path.join(module_path, item)):
-                    result += self.find_modules_recursive(module + '.' + item)
+                item, _ = os.path.splitext(item)
+                result += self.find_modules_recursive(module + '.' + item)
         return result
 
 

From 92090162927bc1513ff9fe2306b11d76358f4e6b Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Mon, 19 Oct 2020 13:02:35 -0700
Subject: [PATCH 3/4] the joys of python 3.5

---
 test-data/unit/cmdline.test | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test-data/unit/cmdline.test b/test-data/unit/cmdline.test
index c731cd64dcc2..2892446b2279 100644
--- a/test-data/unit/cmdline.test
+++ b/test-data/unit/cmdline.test
@@ -794,7 +794,7 @@ src/anamespace/foo/bar.py:2: error: Incompatible return value type (got "int", e
 [case testNestedPEP420Packages]
 # cmd: mypy -p bottles --namespace-packages
 [file bottles/jars/secret/glitter.py]
-x: str = 0
+x = 0  # type: str
 [file bottles/jars/sprinkle.py]
 from bottles.jars.secret.glitter import x
 x + 1

From 3b056b76221bbb1885afcb13697888fe9db24fbd Mon Sep 17 00:00:00 2001
From: hauntsaninja <>
Date: Fri, 23 Oct 2020 15:22:00 -0700
Subject: [PATCH 4/4] modulefinder: remove useless check

---
 mypy/modulefinder.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypy/modulefinder.py b/mypy/modulefinder.py
index 5dc5689915bc..576354c5abcb 100644
--- a/mypy/modulefinder.py
+++ b/mypy/modulefinder.py
@@ -387,7 +387,7 @@ def find_modules_recursive(self, module: str) -> List[BuildSource]:
                     if mod not in hits:
                         hits.add(mod)
                         result += self.find_modules_recursive(module + '.' + mod)
-        elif os.path.isdir(module_path) and any(module.startswith(p) for p in self.ns_packages):
+        elif os.path.isdir(module_path):
             # Even subtler: handle recursive decent into PEP 420
             # namespace packages that are explicitly listed on the command
             # line with -p/--packages.