add git-fixup and documentation for use case

This is a nice new use case for git-deps which makes it even easier
to amend commits buried in the history.

1 files changed, 17 insertions, 0 deletions

diff --git a/bin/git-fixup b/bin/git-fixup
new file mode 100755
index 0000000..a79c655
--- /dev/null
+++ b/bin/git-fixup
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+if ! git commit -m 'fixup commit'; then
+    echo >&2 "Failed to create fixup commit; aborting."
+    exit 1
+fi
+
+deps=( $( git deps HEAD^! ) )
+if [ ${#deps[@]} != 1 ]; then
+    echo >&2 "Failed to find a single dependency of the fixup commit; aborting."
+    git reset --soft HEAD^
+    exit 1
+fi
+
+git commit --amend --fixup=$deps
+
+# TODO: support optionally triggering the rebase.