filter-branch: nearest-ancestor rewriting outside subdir filter

[thirdparty/git.git] / Documentation / git-filter-branch.txt

diff --git a/Documentation/git-filter-branch.txt b/Documentation/git-filter-branch.txt
index c1193953a128201be821538176c1fd666950afb3..394a77a35f2019f5c86f9e90e94b88cf56da04ae 100644 (file)
--- a/Documentation/git-filter-branch.txt
+++ b/Documentation/git-filter-branch.txt
@@ -12,6 +12,7 @@ SYNOPSIS
        [--index-filter <command>] [--parent-filter <command>]
        [--msg-filter <command>] [--commit-filter <command>]
        [--tag-name-filter <command>] [--subdirectory-filter <directory>]
+       [--prune-empty]
        [--original <namespace>] [-d <directory>] [-f | --force]
        [--] [<rev-list options>...]
 
@@ -94,7 +95,9 @@ OPTIONS
 --index-filter <command>::
        This is the filter for rewriting the index.  It is similar to the
        tree filter but does not check out the tree, which makes it much
-       faster.  For hairy cases, see linkgit:git-update-index[1].
+       faster.  Frequently used with `git rm \--cached
+       \--ignore-unmatch ...`, see EXAMPLES below.  For hairy
+       cases, see linkgit:git-update-index[1].
 
 --parent-filter <command>::
        This is the filter for rewriting the commit's parent list.
@@ -156,7 +159,18 @@ to other tags will be rewritten to point to the underlying commit.
 --subdirectory-filter <directory>::
        Only look at the history which touches the given subdirectory.
        The result will contain that directory (and only that) as its
-       project root.
+       project root.  Implies --remap-to-ancestor.
+
+--remap-to-ancestor::
+       Rewrite refs to the nearest rewritten ancestor instead of
+       ignoring them.
++
+Normally, positive refs on the command line are only changed if the
+commit they point to was rewritten.  However, you can limit the extent
+of this rewriting by using linkgit:rev-list[1] arguments, e.g., path
+limiters.  Refs pointing to such excluded commits would then normally
+be ignored.  With this option, they are instead rewritten to point at
+the nearest ancestor that was not excluded.
 
 --prune-empty::
        Some kind of filters will generate empty commits, that left the tree
@@ -207,19 +221,18 @@ However, if the file is absent from the tree of some commit,
 a simple `rm filename` will fail for that tree and commit.
 Thus you may instead want to use `rm -f filename` as the script.
 
-A significantly faster version:
+Using `\--index-filter` with 'git-rm' yields a significantly faster
+version.  Like with using `rm filename`, `git rm --cached filename`
+will fail if the file is absent from the tree of a commit.  If you
+want to "completely forget" a file, it does not matter when it entered
+history, so we also add `\--ignore-unmatch`:
 
 --------------------------------------------------------------------------
-git filter-branch --index-filter 'git rm --cached filename' HEAD
+git filter-branch --index-filter 'git rm --cached --ignore-unmatch filename' HEAD
 --------------------------------------------------------------------------
 
 Now, you will get the rewritten history saved in HEAD.
 
-As with using `rm filename`, `git rm --cached filename` will fail
-if the file is absent from the tree of a commit.  If it is not important
-whether the file is already absent from the tree, you can use
-`git rm --cached --ignore-unmatch filename` instead.
-
 To rewrite the repository to look as if `foodir/` had been its project
 root, and discard all other history:
 
@@ -304,6 +317,16 @@ range in addition to the new branch name.  The new branch name will
 point to the top-most revision that a 'git-rev-list' of this range
 will print.
 
+If you need to add 'Acked-by' lines to, say, the last 10 commits (none
+of which is a merge), use this command:
+
+--------------------------------------------------------
+git filter-branch --msg-filter '
+       cat &&
+       echo "Acked-by: Bugs Bunny <bunny@bugzilla.org>"
+' HEAD~10..HEAD
+--------------------------------------------------------
+
 *NOTE* the changes introduced by the commits, and which are not reverted
 by subsequent commits, will still be in the rewritten branch. If you want
 to throw out _changes_ together with the commits, you should use the