Document use of three dot diff

Documents change proposed in infection/infection#1654
bdsl · Jan 24, 2022 · 24c4a52 · 24c4a52
1 parent 7d2ece0
commit 24c4a52
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/guide/command-line-options.md b/src/guide/command-line-options.md
@@ -122,7 +122,7 @@ git fetch --depth=1 origin $GITHUB_BASE_REF
 infection.phar --git-diff-filter=A
 ```
 
-This command will mutate only those files, that were added in the Pull Request. The diff is done between the current branch and the base branch.
+This command will mutate only those files that were added in the Pull Request. The diff is done between the current branch and a common ancestor of it and the base branch, using git's three-dot diff.
 
 > It's possible to configure the base branch, see [`--git-diff-base`](/guide/command-line-options.html#git-diff-base) option