Ensure that the cached file is not empty before using it (#251)

* Update expected test results

Signed-off-by: Marcel Bochtler <marcel.bochtler@bosch.com>

* Ensure that the cached file is not empty before using it

We've observed multiple cases where a zero-byte file is cached, leading
to crashes with the error message:

    zipfile.BadZipFile: File is not a zip file

I was not able to reproduce this issue reliably enough to identify the
root cause. However, adding a check to ensure that the cached file is
not empty before using it will mitigate the problem.

Signed-off-by: Marcel Bochtler <marcel.bochtler@bosch.com>

---------

Signed-off-by: Marcel Bochtler <marcel.bochtler@bosch.com>

Author: MarcelBochtler

src/python_inspector/utils_pypi.py

@@ -1694,7 +1694,14 @@ async def get(
         cached = os.path.join(self.directory, cache_key)
         lock_file = f"{cached}.lockfile"
 
-        if force or not os.path.exists(cached):
+        cache_valid = os.path.exists(cached) and os.path.getsize(cached) > 0
+
+        if force or not cache_valid:
+            if not cache_valid and os.path.exists(cached):
+                if TRACE_DEEP:
+                    print(f"        FILE CACHE INVALID (empty file): {path_or_url}")
+                os.remove(cached)
+
             if TRACE_DEEP:
                 print(f"        FILE CACHE MISS: {path_or_url}")
             content = await get_file_content(

tests/data/azure-devops.req-310-expected.json

@@ -3727,12 +3727,12 @@
       "type": "pypi",
       "namespace": null,
       "name": "pip",
-      "version": "25.2",
+      "version": "25.3",
       "qualifiers": {},
       "subpath": null,
       "primary_language": "Python",
       "description": "The PyPA recommended tool for installing Python packages.\npip - The Python Package Installer\n==================================\n\n.. |pypi-version| image:: https://img.shields.io/pypi/v/pip.svg\n   :target: https://pypi.org/project/pip/\n   :alt: PyPI\n\n.. |python-versions| image:: https://img.shields.io/pypi/pyversions/pip\n   :target: https://pypi.org/project/pip\n   :alt: PyPI - Python Version\n\n.. |docs-badge| image:: https://readthedocs.org/projects/pip/badge/?version=latest\n   :target: https://pip.pypa.io/en/latest\n   :alt: Documentation\n\n|pypi-version| |python-versions| |docs-badge|\n\npip is the `package installer`_ for Python. You can use pip to install packages from the `Python Package Index`_ and other indexes.\n\nPlease take a look at our documentation for how to install and use pip:\n\n* `Installation`_\n* `Usage`_\n\nWe release updates regularly, with a new version every 3 months. Find more details in our documentation:\n\n* `Release notes`_\n* `Release process`_\n\nIf you find bugs, need help, or want to talk to the developers, please use our mailing lists or chat rooms:\n\n* `Issue tracking`_\n* `Discourse channel`_\n* `User IRC`_\n\nIf you want to get involved head over to GitHub to get the source code, look at our development documentation and feel free to jump on the developer mailing lists and chat rooms:\n\n* `GitHub page`_\n* `Development documentation`_\n* `Development IRC`_\n\nCode of Conduct\n---------------\n\nEveryone interacting in the pip project's codebases, issue trackers, chat\nrooms, and mailing lists is expected to follow the `PSF Code of Conduct`_.\n\n.. _package installer: https://packaging.python.org/guides/tool-recommendations/\n.. _Python Package Index: https://pypi.org\n.. _Installation: https://pip.pypa.io/en/stable/installation/\n.. _Usage: https://pip.pypa.io/en/stable/\n.. _Release notes: https://pip.pypa.io/en/stable/news.html\n.. _Release process: https://pip.pypa.io/en/latest/development/release-process/\n.. _GitHub page: https://github.com/pypa/pip\n.. _Development documentation: https://pip.pypa.io/en/latest/development\n.. _Issue tracking: https://github.com/pypa/pip/issues\n.. _Discourse channel: https://discuss.python.org/c/packaging\n.. _User IRC: https://kiwiirc.com/nextclient/#ircs://irc.libera.chat:+6697/pypa\n.. _Development IRC: https://kiwiirc.com/nextclient/#ircs://irc.libera.chat:+6697/pypa-dev\n.. _PSF Code of Conduct: https://github.com/pypa/.github/blob/main/CODE_OF_CONDUCT.md",
-      "release_date": "2025-07-30T21:50:13",
+      "release_date": "2025-10-25T00:55:39",
       "parties": [
         {
           "type": "person",
@@ -3759,11 +3759,11 @@
         "Topic :: Software Development :: Build Tools"
       ],
       "homepage_url": null,
-      "download_url": "https://files.pythonhosted.org/packages/b7/3f/945ef7ab14dc4f9d7f40288d2df998d1837ee0888ec3659c813487572faa/pip-25.2-py3-none-any.whl",
-      "size": 1752557,
+      "download_url": "https://files.pythonhosted.org/packages/44/3c/d717024885424591d5376220b5e836c2d5293ce2011523c9de23ff7bf068/pip-25.3-py3-none-any.whl",
+      "size": 1778622,
       "sha1": null,
-      "md5": "52af72c263169cc46cc32bed310a5eab",
-      "sha256": "6d67a2b4e7f14d8b31b8b52648866fa717f45a1eb70e83002f4331d07e953717",
+      "md5": "4bbbf9f0745c4117c8ecc77c561ef74b",
+      "sha256": "9655943313a94722b7774661c21049070f6bbb0a1516bf02f7c8d5d9201514cd",
       "sha512": null,
       "bug_tracking_url": null,
       "code_view_url": "https://github.com/pypa/pip",
@@ -3778,9 +3778,9 @@
       "dependencies": [],
       "repository_homepage_url": null,
       "repository_download_url": null,
-      "api_data_url": "https://pypi.org/pypi/pip/25.2/json",
+      "api_data_url": "https://pypi.org/pypi/pip/25.3/json",
       "datasource_id": null,
-      "purl": "pkg:pypi/pip@25.2"
+      "purl": "pkg:pypi/pip@25.3"
     },
     {
       "type": "pypi",
@@ -6158,13 +6158,13 @@
       ]
     },
     {
-      "package": "pkg:pypi/pip@25.2",
+      "package": "pkg:pypi/pip@25.3",
       "dependencies": []
     },
     {
       "package": "pkg:pypi/pipdeptree@2.2.1",
       "dependencies": [
-        "pkg:pypi/pip@25.2"
+        "pkg:pypi/pip@25.3"
       ]
     },
     {