Understanding delta file changes and merge conflicts in Git pull requests

This post clarifies the process of determining delta file changes (Δchanges) in Git pull requests by comparing the source and target branches against their merge-base commit. It explains that commits before the merge-base are ignored and that changes are calculated based on commits made after the merge-base on the source branch. The post also details how merge conflicts occur when both branches modify the same file after the merge-base and provides an explanation for scenarios where Git appears to ignore file changes due to the comparison logic, even without explicit conflicts. It suggests using `git merge-base` to identify the merge-base commit and compare branch heads to understand merge outcomes.