git checkout release-1.1 <file>
release-1.0 <--- release-1.1
c1 <--- c2 <--- c3 <--- c4 <--- c5 <--- c6 <--- master
release-1.0 <--- release-1.1 <----------------------\
c1 <--- c2 <--- c3 <--- c4 <--- c5 <--- c6 <--- c7 <--- master
I don't see any way around dealing with potential merge conflicts, because the hotfix was made on a much older version of the branch.
One option would be to cherry-pick the hotfix commit, and then choose the version of the files from the latest
master branch for all files except for the 10 files involved in the hotfix:
git checkout master git cherry-pick <SHA-1 release-1.1>
<SHA-1 release 1.1> is the SHA-1 hash of the hotfix commit in the
release-1.1 branch. Keep in mind you may get conflicts in the 10 hotfix files themselves. In this case, you should focus on the hotfix changes, tending to choose the latest
master version in all other cases.