# overlap function context of 1st change and -u context of 2nd change
grep -v "delete me from hello" <"$dir/hello.c" >file.c &&
- sed 2p <"$dir/dummy.c" >>file.c &&
+ sed "2a\\
+ extra line" <"$dir/dummy.c" >>file.c &&
commit_and_tag changed_hello_dummy file.c &&
git checkout initial &&