git-read-tree(1)
================
-v0.1, May 2005
NAME
----
-git-read-tree - Reads tree information into the directory cache
+git-read-tree - Reads tree information into the index
SYNOPSIS
--------
-'git-read-tree' (<tree-ish> | [-m [-u]] <tree-ish1> [<tree-ish2> [<tree-ish3>]])
+'git-read-tree' (<tree-ish> | [-m [-u|-i]] <tree-ish1> [<tree-ish2> [<tree-ish3>]])
DESCRIPTION
-----------
-Reads the tree information given by <tree-ish> into the directory cache,
+Reads the tree information given by <tree-ish> into the index,
but does not actually *update* any of the files it "caches". (see:
-git-checkout-cache)
+git-checkout-index)
-Optionally, it can merge a tree into the cache, perform a
+Optionally, it can merge a tree into the index, perform a
fast-forward (i.e. 2-way) merge, or a 3-way merge, with the -m
flag. When used with -m, the -u flag causes it to also update
the files in the work tree with the result of the merge.
-m::
Perform a merge, not just a read.
+--reset::
+
+ Same as -m except that unmerged entries will be silently ignored.
+
-u::
After a successful merge, update the files in the work
tree with the result of the merge.
+-i::
+ Usually a merge requires the index file as well as the
+ files in the working tree are up to date with the
+ current head commit, in order not to lose local
+ changes. This flag disables the check with the working
+ tree and is meant to be used when creating a merge of
+ trees that are not directly related to the current
+ working tree status into a temporary index file.
+
+
<tree-ish#>::
The id of the tree object(s) to be read/merged.
Merging
-------
-If '-m' is specified, "git-read-tree" can performs 3 kinds of
+If '-m' is specified, "git-read-tree" can perform 3 kinds of
merge, a single tree merge if only 1 tree is given, a
fast-forward merge with 2 trees, or a 3-way merge if 3 trees are
provided.
Single Tree Merge
~~~~~~~~~~~~~~~~~
If only 1 tree is specified, git-read-tree operates as if the user did not
-specify '-m', except that if the original cache has an entry for a
-given pathname; and the contents of the path matches with the tree
-being read, the stat info from the cache is used. (In other words, the
-cache's stat()s take precedence over the merged tree's)
+specify '-m', except that if the original index has an entry for a
+given pathname, and the contents of the path matches with the tree
+being read, the stat info from the index is used. (In other words, the
+index's stat()s take precedence over the merged tree's).
That means that if you do a "git-read-tree -m <newtree>" followed by a
-"git-checkout-cache -f -u -a", the "git-checkout-cache" only checks out
+"git-checkout-index -f -u -a", the "git-checkout-index" only checks out
the stuff that really changed.
This is used to avoid unnecessary false hits when "git-diff-files" is
When two trees are specified, the user is telling git-read-tree
the following:
- (1) The current index and work tree is derived from $H, but
+ 1. The current index and work tree is derived from $H, but
the user may have local changes in them since $H;
- (2) The user wants to fast-forward to $M.
+ 2. The user wants to fast-forward to $M.
In this case, the "git-read-tree -m $H $M" command makes sure
that no local change is lost as the result of this "merge".
-------------------------------------------------------
0 nothing nothing nothing (does not happen)
1 nothing nothing exists use M
- 2 nothing exists nothing remove path from cache
+ 2 nothing exists nothing remove path from index
3 nothing exists exists use M
clean I==H I==M
8 yes N/A no nothing exists fail
9 no N/A no nothing exists fail
- 10 yes yes N/A exists nothing remove path from cache
+ 10 yes yes N/A exists nothing remove path from index
11 no yes N/A exists nothing fail
12 yes no N/A exists nothing fail
13 no no N/A exists nothing fail
20 yes yes no exists exists use M
21 no yes no exists exists fail
-In all "keep index" cases, the cache entry stays as in the
+In all "keep index" cases, the index entry stays as in the
original index file. If the entry were not up to date,
git-read-tree keeps the copy in the work tree intact when
operating under the -u flag.
When this form of git-read-tree returns successfully, you can
see what "local changes" you made are carried forward by running
-"git-diff-cache --cached $M". Note that this does not
-necessarily match "git-diff-cache --cached $H" would have
+"git-diff-index --cached $M". Note that this does not
+necessarily match "git-diff-index --cached $H" would have
produced before such a two tree merge. This is because of cases
18 and 19 --- if you already had the changes in $M (e.g. maybe
-you picked it up via e-mail in a patch form), "git-diff-cache
+you picked it up via e-mail in a patch form), "git-diff-index
--cached $H" would have told you about the change before this
-merge, but it would not show in "git-diff-cache --cached $M"
+merge, but it would not show in "git-diff-index --cached $M"
output after two-tree merge.
automatically collapse to "merged" state by git-read-tree.
- a file that has _any_ difference what-so-ever in the three trees
- will stay as separate entries in the index. It's up to "script
+ will stay as separate entries in the index. It's up to "porcelain
policy" to determine how to remove the non-0 stages, and insert a
merged version.
matching "stage1" entry if it exists too. .. all the normal
trivial rules ..
-You would normally use "git-merge-cache" with supplied
-"git-merge-one-file-script" to do this last step. The script
+You would normally use "git-merge-index" with supplied
+"git-merge-one-file" to do this last step. The script
does not touch the files in the work tree, and the entire merge
happens in the index file. In other words, there is no need to
worry about what is in the working directory, since it is never
changes. To illustrate, suppose you start from what has been
commited last to your repository:
- $ JC=`cat .git/HEAD`
- $ git-checkout-cache -f -u -a $JC
+ $ JC=`git-rev-parse --verify "HEAD^0"`
+ $ git-checkout-index -f -u -a $JC
-You do random edits, without running git-update-cache. And then
+You do random edits, without running git-update-index. And then
you notice that the tip of your "upstream" tree has advanced
since you pulled from him:
- $ git-fetch-script rsync://.... linus
+ $ git-fetch rsync://.... linus
$ LT=`cat .git/MERGE_HEAD`
Your work tree is still based on your HEAD ($JC), but you have
some edits since. Three-way merge makes sure that you have not
-added or modified cache entries since $JC, and if you haven't,
+added or modified index entries since $JC, and if you haven't,
then does the right thing. So with the following sequence:
$ git-read-tree -m -u `git-merge-base $JC $LT` $JC $LT
- $ git-merge-cache git-merge-one-file-script -a
+ $ git-merge-index git-merge-one-file -a
$ echo "Merge with Linus" | \
git-commit-tree `git-write-tree` -p $JC -p $LT
See Also
--------
-link:git-write-tree.html[git-write-tree]; link:git-ls-files.html[git-ls-files]
+gitlink:git-write-tree[1]; gitlink:git-ls-files[1]
Author
GIT
---
-Part of the link:git.html[git] suite
+Part of the gitlink:git[7] suite