How do I transfer diff hunks between files in Vim's diff mode?

Explanation

When comparing two files side by side in Vim's diff mode (:diffsplit or vim -d file1 file2), you often want to accept or push individual changes between the files. The dp and do commands let you transfer diff hunks without manual copy-pasting, making conflict resolution and file merging dramatically faster.

How it works

• dp (diff put): Pushes the current hunk from the buffer your cursor is in to the other buffer. The other file receives the change.
• do (diff obtain): Pulls the current hunk from the other buffer into the buffer your cursor is in. Your file receives the change.
• Both commands operate on the diff hunk under the cursor. Navigate between hunks with ]c (next) and [c (previous).
• After transferring a hunk, Vim automatically updates the diff highlighting.

Example

With two files open in diff mode:

  file1.txt        |  file2.txt
  ─────────────────┼─────────────────
  hello world      |  hello world
  foo              |  bar           ← difference
  goodbye          |  goodbye

With cursor on the foo/bar hunk in file1.txt:

• Press dp → pushes foo to file2.txt (both files now have foo)
• Press do → obtains bar from file2.txt (both files now have bar)

Tips

• Use :diffupdate if the highlighting gets out of sync after edits
• Combine with ]c and [c for a rapid workflow: ]c to jump to next hunk, then do or dp to resolve it
• In a three-way merge, do and dp work with the buffer that shares the diff hunk — use :diffget {bufnr} for explicit control
• Remember: dp = "put" (push to other), do = "obtain" (pull from other)