| The Utilities/cmlibarchive directory contains a reduced distribution |
| of the libarchive source tree with only the library source code and |
| CMake build system. It is not a submodule; the actual content is part |
| of our source tree and changes can be made and committed directly. |
| |
| We update from upstream using Git's "subtree" merge strategy. A |
| special branch contains commits of upstream libarchive snapshots and |
| nothing else. No Git ref points explicitly to the head of this |
| branch, but it is merged into our history. |
| |
| Update libarchive from upstream as follows. Create a local branch to |
| explicitly reference the upstream snapshot branch head: |
| |
| git branch libarchive-upstream 37f225b7 |
| |
| Use a temporary directory to checkout the branch: |
| |
| mkdir libarchive-tmp |
| cd libarchive-tmp |
| git init |
| git pull .. libarchive-upstream |
| rm -rf * |
| |
| Now place the (reduced) libarchive content in this directory. See |
| instructions shown by |
| |
| git log 37f225b7 |
| |
| for help extracting the content from the upstream svn repo. Then run |
| the following commands to commit the new version. Substitute the |
| appropriate date and version number: |
| |
| git add --all |
| |
| GIT_AUTHOR_NAME='LibArchive Upstream' \ |
| GIT_AUTHOR_EMAIL='libarchive-discuss@googlegroups.com' \ |
| GIT_AUTHOR_DATE='Mon Apr 14 19:19:05 2014 -0700' \ |
| git commit -m 'libarchive 3.1.2-246-ga5a5d28b (reduced)' && |
| git commit --amend |
| |
| Edit the commit message to describe the procedure used to obtain the |
| content. Then push the changes back up to the main local repository: |
| |
| git push .. HEAD:libarchive-upstream |
| cd .. |
| rm -rf libarchive-tmp |
| |
| Create a topic in the main repository on which to perform the update: |
| |
| git checkout -b update-libarchive master |
| |
| Merge the libarchive-upstream branch as a subtree: |
| |
| git merge -s recursive -X subtree=Utilities/cmlibarchive \ |
| libarchive-upstream |
| |
| If there are conflicts, resolve them and commit. Build and test the |
| tree. Commit any additional changes needed to succeed. |
| |
| Finally, run |
| |
| git rev-parse --short=8 libarchive-upstream |
| |
| to get the commit from which the libarchive-upstream branch must be started |
| on the next update. Edit the "git branch libarchive-upstream" line above to |
| record it, and commit this file. |