aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Documentation/git-checkout.txt76
-rwxr-xr-xgit-checkout.sh60
2 files changed, 107 insertions, 29 deletions
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 9442c66b1..df9a61867 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -7,7 +7,7 @@ git-checkout - Checkout and switch to a branch.
SYNOPSIS
--------
-'git-checkout' [-f] [-b <new_branch>] [<branch>] [<paths>...]
+'git-checkout' [-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]
DESCRIPTION
-----------
@@ -34,6 +34,19 @@ OPTIONS
-b::
Create a new branch and start it at <branch>.
+-m::
+ If you have local modifications to a file that is
+ different between the current branch and the branch you
+ are switching to, the command refuses to switch
+ branches, to preserve your modifications in context.
+ With this option, a three-way merge between the current
+ branch, your working tree contents, and the new branch
+ is done, and you will be on the new branch.
++
+When a merge conflict happens, the index entries for conflicting
+paths are left unmerged, and you need to resolve the conflicts
+and mark the resolved paths with `git update-index`.
+
<new_branch>::
Name for the new branch.
@@ -42,13 +55,13 @@ OPTIONS
commit. Defaults to HEAD.
-EXAMPLE
--------
+EXAMPLES
+--------
-The following sequence checks out the `master` branch, reverts
+. The following sequence checks out the `master` branch, reverts
the `Makefile` to two revisions back, deletes hello.c by
mistake, and gets it back from the index.
-
++
------------
$ git checkout master <1>
$ git checkout master~2 Makefile <2>
@@ -59,15 +72,64 @@ $ git checkout hello.c <3>
<2> take out a file out of other commit
<3> or "git checkout -- hello.c", as in the next example.
------------
-
++
If you have an unfortunate branch that is named `hello.c`, the
last step above would be confused as an instruction to switch to
that branch. You should instead write:
-
++
------------
$ git checkout -- hello.c
------------
+. After working in a wrong branch, switching to the correct
+branch you would want to is done with:
++
+------------
+$ git checkout mytopic
+------------
++
+However, your "wrong" branch and correct "mytopic" branch may
+differ in files that you have locally modified, in which case,
+the above checkout would fail like this:
++
+------------
+$ git checkout mytopic
+fatal: Entry 'frotz' not uptodate. Cannot merge.
+------------
++
+You can give the `-m` flag to the command, which would try a
+three-way merge:
++
+------------
+$ git checkout -m mytopic
+Auto-merging frotz
+------------
++
+After this three-way merge, the local modifications are _not_
+registered in your index file, so `git diff` would show you what
+changes you made since the tip of the new branch.
+
+. When a merge conflict happens during switching branches with
+the `-m` option, you would see something like this:
++
+------------
+$ git checkout -m mytopic
+Auto-merging frotz
+merge: warning: conflicts during merge
+ERROR: Merge conflict in frotz
+fatal: merge program failed
+------------
++
+At this point, `git diff` shows the changes cleanly merged as in
+the previous example, as well as the changes in the conflicted
+files. Edit and resolve the conflict and mark it resolved with
+`git update-index` as usual:
++
+------------
+$ edit frotz
+$ git update-index frotz
+------------
+
Author
------
diff --git a/git-checkout.sh b/git-checkout.sh
index 76e6a41c6..bd7f00730 100755
--- a/git-checkout.sh
+++ b/git-checkout.sh
@@ -1,6 +1,6 @@
#!/bin/sh
-USAGE='[-f] [-b <new_branch>] [<branch>] [<paths>...]'
+USAGE='[-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]'
SUBDIRECTORY_OK=Sometimes
. git-sh-setup
@@ -9,6 +9,7 @@ new=
force=
branch=
newbranch=
+merge=
while [ "$#" != "0" ]; do
arg="$1"
shift
@@ -26,6 +27,9 @@ while [ "$#" != "0" ]; do
"-f")
force=1
;;
+ -m)
+ merge=1
+ ;;
--)
break
;;
@@ -71,7 +75,7 @@ done
if test "$#" -ge 1
then
- if test '' != "$newbranch$force"
+ if test '' != "$newbranch$force$merge"
then
die "updating paths and switching branches or forcing are incompatible."
fi
@@ -121,32 +125,44 @@ then
git-checkout-index -q -f -u -a
else
git-update-index --refresh >/dev/null
- git-read-tree -m -u $old $new || (
- echo >&2 -n "Try automerge [y/N]? "
- read yesno
- case "$yesno" in [yY]*) ;; *) exit 1 ;; esac
-
- # NEEDSWORK: We may want to reset the index from the $new for
- # these paths after the automerge happens, but it is not done
- # yet. Probably we need to leave unmerged ones alone, and
- # yank the object name & mode from $new for cleanly merged
- # paths and stuff them in the index.
-
- names=`git diff-files --name-only`
- case "$names" in
- '') ;;
- *)
- echo "$names" | git update-index --remove --stdin ;;
+ merge_error=$(git-read-tree -m -u $old $new 2>&1) || (
+ case "$merge" in
+ '')
+ echo >&2 "$merge_error"
+ exit 1 ;;
esac
+ # Match the index to the working tree, and do a three-way.
+ git diff-files --name-only | git update-index --remove --stdin &&
work=`git write-tree` &&
- git read-tree -m -u $old $work $new || exit
+ git read-tree --reset $new &&
+ git checkout-index -f -u -q -a &&
+ git read-tree -m -u $old $new $work || exit
+
if result=`git write-tree 2>/dev/null`
then
- echo >&2 "Trivially automerged." ;# can this even happen?
- exit 0
+ echo >&2 "Trivially automerged."
+ else
+ git merge-index -o git-merge-one-file -a
fi
- git merge-index -o git-merge-one-file -a
+
+ # Do not register the cleanly merged paths in the index yet.
+ # this is not a real merge before committing, but just carrying
+ # the working tree changes along.
+ unmerged=`git ls-files -u`
+ git read-tree --reset $new
+ case "$unmerged" in
+ '') ;;
+ *)
+ (
+ z40=0000000000000000000000000000000000000000
+ echo "$unmerged" |
+ sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /"
+ echo "$unmerged"
+ ) | git update-index --index-info
+ ;;
+ esac
+ exit 0
)
fi