patchAdd new --index-filter example to git-filter-branch.txt

At work I patched git with the prevously sent --egrep-filter patch that allows an irregular history to be retained, like where code reorganization occured and you want to keep the history from the original locations.

The comments I recieved at that time was that my case was an --index-filter variant.

I've reworked it into an --index-filter using the $GIT_COMMIT variable, tested that it works, and have added it as an example to the git-filter-branch documentation.

Michael O'Cleirigh (1):
  Documentation/git-filter-branch: add --index-filter example

 Documentation/git-filter-branch.txt |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

Added an example using git ls-tree on the $GIT_COMMIT and then filtering what should remain in the history using egrep.

This allows multiple paths accross history to be retained when filtering a branch.
---
 Documentation/git-filter-branch.txt |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

I like the example, particularly because it shows that it is not necessary to start off with index's content in an --index-filter, and that the index can be replaced with read-tree -i, i.e., GIT_INDEX_FILE juggling is not necessary for some tasks.

Am 27.04.2011 20:08, schrieb Michael O'Cleirigh:

Sign-off is missing. Please keep lines well below 75 characters. Write 'Add an example...' rather than 'Added an example...'.

This places the new text in the middle of another example, doesn't it?

The prefered style of examples to give motivation first, then the example command, then a description of command details. I would drop the sentence "i.e. ... was reoranized... history" because it does not add value for the reader (I can think of other equally or even more likely reason why the interesting path structure is irregular).

The example looks better when it is broken into more lines, e.g. like this:

-----------------------------------------------------------
git filter-branch --prune-empty --index-filter '
		git ls-tree $GIT_COMMIT |
		egrep "(top-dir-A|top-dir-B|other-dir-C)" |
 		git mktree | xargs git read-tree -i -m'
-----------------------------------------------------------

And the dash lines are just as long as necessary.

-- Hannes

Heya,

On Wed, Apr 27, 2011 at 20:08, Michael O'Cleirigh <michael.ocleirigh@rivulet.ca> wrote:

Meta nit: for a 1 patch series we would usually put this kind of introduction after the --- in the actual patch.