How to import a GitHub repository as a subdirectory of a new repository while maintaining commits and datestamps
There is probably a better way to do this, but this worked for me.
I had a repository called docsearch that I had been building a prototype in.
I wanted to move the contents of that repository into an existing repository called search_experiments - but I wanted the contents to live in a docsearch/ subdirectory rather than living in the root of the repo.
I solved this using the combination of git format-patch and git apply.
First, I created a list of patch files in my docsearch repo by running this:
cd docsearch
git format-patch --root
The --root option means "start at the first commit in the repo". This produced a list of patch files:
docsearch $ ls -l *.patch
-rw-r--r-- 1 simonw staff 3910 Oct 31 11:11 0001-First-working-version.patch
-rw-r--r-- 1 simonw staff 6591 Oct 31 11:11 0002-Implemented-faceted-search.patch
-rw-r--r-- 1 simonw staff 1403 Oct 31 11:11 0003-Add-updated_by-facet.patch
-rw-r--r-- 1 simonw staff 1558 Oct 31 11:11 0004-Don-t-show-snippet-if-no-search-term.patch
-rw-r--r-- 1 simonw staff 1211 Oct 31 11:11 0005-Use-searchterm-for-better-autocomplete.patch
-rw-r--r-- 1 simonw staff 1372 Oct 31 11:11 0006-Show-truncated-content-summary-if-no-snippet.patch
I then manually applied these patches to the other repository, one at a time - but I used the git apply --directory=docsearch option to get the patches to create files in a new subdirectory. I did the following for each patch file:
cd ../search_experiments/
git apply --directory=docsearch ../docsearch/0001-First-working-version.patch
# This applies changes but does not commit. Commit them, duplicating the old commit message
git add docsearch
git commit -m "First working version of docsearch" # Manually copied commit message
# Last step: manually edit the date to reflect the old commit
git commit --amend --no-edit --date "Thu, 27 Sep 2018 10:54:02 -0700"
Since I only had 6 patches I didn't bother to investigate further options for automating the commit message and date duplication.