Unable to retrieve changed files on a "push" event ("pull_request" works though)

[irasnyd]

Describe the bug

I have a workflow which uses this action (version 1.2.3, since version 1.2.4 doesn't work for me, see Issue #102).

My workflow triggers on both push and pull_request. However, the push triggered workflow run always fails, while the pull_request triggered workflow run works correctly. It runs the same exact workflow for both triggers, however the file-changes-action step fails when running the push trigger. I have attached the logs.

Workflow
See attached syntaxcheck.zip

Expected behavior

The file-changes-action should work for push triggered workflows.

Additional context

Here are the logs from a "push + pull_request" triggered run.

• Push event (fails): logs_171.zip
• PR event (works): logs_172.zip

Thank you for this project! When it works, it works great! I really appreciate you making it available for us to use.

[thoellrich]

@irasnyd - I see the exact same error here for push when a branch is pushed the first time. In that case there is no previous sha to compare to and it defaults to 0000...., which causes the error we are seeing.