pip: combine chdir and env only when env is set (#40793)

* pip: combine chdir and env only when env is set

This fixes an AttributeError when chdir without virtualenv is specified:

 File "/tmp/ansible_2UAFsZ/ansible_module_pip.py", line 387, in main
    env = os.path.join(chdir, env)
 File "/usr/lib64/python2.7/posixpath.py", line 75, in join
    if b.startswith('/'):
AttributeError: 'NoneType' object has no attribute 'startswith'

* Add test for pip with chdir

Signed-off-by: Till Maas <opensource@till.name>

lib/ansible/modules/packaging/language/pip.py

@@ -457,7 +457,7 @@ def main():
     env = module.params['virtualenv']
 
     venv_created = False
-    if chdir:
+    if env and chdir:
         env = os.path.join(chdir, env)
 
     if umask and not isinstance(umask, int):

test/integration/targets/pip/files/ansible_test_pip_chdir/__init__.py

@@ -0,0 +1,2 @@
+def main():
+    print("success")

test/integration/targets/pip/files/setup.py

@@ -0,0 +1,14 @@
+#!/usr/bin/env python
+
+from setuptools import setup, find_packages
+
+setup(
+    name="ansible_test_pip_chdir",
+    version="0",
+    packages=find_packages(),
+    entry_points={
+        'console_scripts': [
+            'ansible_test_pip_chdir = ansible_test_pip_chdir:main'
+        ]
+    }
+)

test/integration/targets/pip/tasks/pip.yml

@@ -230,6 +230,48 @@
     that:
       - "pip_install_venv is changed"
 
+# https://github.com/ansible/ansible/issues/37912
+# support chdir without virtualenv
+- name: create chdir test directories
+  file:
+    state: directory
+    name: "{{ output_dir }}/{{ item }}"
+  loop:
+    - pip_module
+    - pip_root
+    - pip_module/ansible_test_pip_chdir
+
+- name: copy test module
+  copy:
+    src: "{{ item }}"
+    dest: "{{ output_dir }}/pip_module/{{ item }}"
+  loop:
+    - setup.py
+    - ansible_test_pip_chdir/__init__.py
+
+- name: install test module
+  pip:
+    name: .
+    chdir: "{{ output_dir }}/pip_module"
+    extra_args: --user --upgrade --root {{ output_dir }}/pip_root
+
+- name: register python_site_lib
+  command: 'python -c "import site; print(site.USER_SITE)"'
+  register: pip_python_site_lib
+
+- name: register python_user_base
+  command: 'python -c "import site; print(site.USER_BASE)"'
+  register: pip_python_user_base
+
+- name: run test module
+  shell: "PYTHONPATH=$(echo {{ output_dir }}/pip_root{{ pip_python_site_lib.stdout }}) {{ output_dir }}/pip_root{{ pip_python_user_base.stdout }}/bin/ansible_test_pip_chdir"
+  register: pip_chdir_command
+
+- name: make sure command ran
+  assert:
+    that:
+      - pip_chdir_command.stdout == "success"
+
 # https://github.com/ansible/ansible/issues/25122
 - name: ensure is a fresh virtualenv
   file: