On Wed, Nov 26, 2014 at 11:22 AM, Derek Moore <derek.p.mo...@gmail.com> wrote: >> Now knowing the edge cases won't work, I did not get an idea about the >> standard case of what should work with this. Would you mind to write >> a more detailed example or a more advertising paragraph of what this can do? >> Not getting the big picture may be related to me having not worked with RCS >> yet. > > Stefan, > > RCS Keywords, while originating from RCS, are commonly used in CVS and > SVN. A lot of LaTeX workflows in the scientific community, for > example, use these keyword substitutions, trapping scientists in > legacy SCMSes. In my environment, we do builds and deployments from > within pristine working copies or "checkouts of trunk", we also have > some deployments that are symlinks into live checkouts of trunk, and > we have production support workflows where support personnel inspect > files remotely and subsequent escalation procedures rely on the > contents of the $Author$ substitutions, etc. As a result of this, > projects that have migrated to git are demanding the restoration of > their RCS keyword substitutions. > > In CVS/SVN, keywords are expanded on checkout, placing text related to > the most recent history of a give file into that file. RCS has one > keyword that takes action on check-in (or commit), being the $Log$ > keyword, which is a running commit log of the file in the file. > Keyword expansions are not stored in the repo, but are substituted on > their out of the repo into the working copy, and substitutions are > reversed on their way from the working copy into the repo.
Thanks for the explanation! > > Git's export-subst feature in git-archive is very similar to RCS > Keywords. What I'm providing here is a mechanism to enable > export-subst functionality throughout normal git workflows and not > just during builds that employ git-archive, as if export-subst worked > alongside git's ident feature. > > Perhaps described the known issues I've found will also help towards > understanding... > > > Known Issues > ------------ > > Edge Case #1 (aka, modified smudge filter) > > 1. create new branch > 2. edit smudge filter > 3. commit > 4. switch back to previous branch > 5. smudge filter is temporarily disappeared at the moment the smudge > filter wants to run > > This edge case is a side-effect of the order in which git performs > deletions in the worktree and extractions from the index and > executions of the filters. This edge case is related to a similar to > one seen in older git versions where the smudge is disappeared during > a "git checkout-index -a -f", but the sequence of operations has been > fixed in more recent gits, so the smudge does not disappear during a > checkout-index. > > > Edge Case #2 > > 1. create branch B from branch A > 2. make changes in branch A, commit > 3. checkout branch B > 4. git merge A > 5. while editing commit file, file being modified lacks keywords (expected) > 6. delete commit message, cancelling commit > 7. file remains w/o substituted keywords > 8. cancel merge w/ git reset --merge ORIG_HEAD & restored original > file is w/o substituted keywords > > Reason: no available state transition on reset --merge > > > Edge Case #3 > > 1. create branch B from branch A, checkout B > 2. modify file, commit > 3. checkout A > 4. make conflicting edit to same file > 5. git rebase B, rebase will conflict > 6. git rebase --abort > 7. file will be w/o substituted keywords > > > Known Unissues > -------------- > > Not-an-Edge-Case #1 > > 1. create branch B from branch A, checkout B > 2. modify file, commit > 3. checkout A > 4. git merge --squash B > 5. file as modified from B is w/o substituted keywords > AS EXPECTED - that version of file does not yet contain history in A, > file will gain substitutions following commit -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
