Get rid of all_are_submodules and add a test for a bug this fixes

Author: msullivan

mypy/build.py

@@ -692,23 +692,17 @@ def correct_rel_imp(imp: Union[ImportFrom, ImportAll]) -> str:
                 elif isinstance(imp, ImportFrom):
                     cur_id = correct_rel_imp(imp)
                     pos = len(res)
-                    all_are_submodules = True
                     # Also add any imported names that are submodules.
                     pri = import_priority(imp, PRI_MED)
                     for name, __ in imp.names:
                         sub_id = cur_id + '.' + name
                         if self.is_module(sub_id):
                             res.append((pri, sub_id, imp.line))
-                        else:
-                            all_are_submodules = False
-                    # If all imported names are submodules, don't add
-                    # cur_id as a dependency.  Otherwise (i.e., if at
-                    # least one imported name isn't a submodule)
-                    # cur_id is also a dependency, and we should
-                    # insert it *before* any submodules.
-                    if not all_are_submodules:
-                        pri = import_priority(imp, PRI_HIGH)
-                        res.insert(pos, ((pri, cur_id, imp.line)))
+                    # Add cur_id as a dependency, even if all of the
+                    # imports are submodules. Processing import from will try
+                    # to look through cur_id, so we should depend on it.
+                    pri = import_priority(imp, PRI_HIGH)
+                    res.insert(pos, ((pri, cur_id, imp.line)))
                 elif isinstance(imp, ImportAll):
                     pri = import_priority(imp, PRI_HIGH)
                     res.append((pri, correct_rel_imp(imp), imp.line))

test-data/unit/check-incremental.test

@@ -4265,3 +4265,20 @@ cache_fine_grained = False
 cache_fine_grained = True
 [rechecked a, builtins]
 [stale a, builtins]
+
+[case testIncrementalPackageNameOverload]
+# cmd: mypy -m main a
+# flags: --follow-imports=skip
+[file main.py]
+from a import x
+x.foo()
+[file a/__init__.py]
+pass
+[file a/__init__.py.2]
+x = 10
+[file a/x.py]
+def foo() -> None:
+    pass
+[out]
+[out2]
+tmp/main.py:2: error: "int" has no attribute "foo"