X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=git-checkout.sh;h=463ed2eaff906edaeb0f6d3f8138798e373c6495;hb=3443546f6ef57fe28ea5cca232df8e400bfc3883;hp=3bbd1117739b02572aece86030bb9f02f3110d34;hpb=36de72aa9dc3b7daf8cf2770c840f39bb0d2ae70;p=git.git

diff --git a/git-checkout.sh b/git-checkout.sh
index 3bbd1117..463ed2ea 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="$1"
     shift
@@ -21,11 +22,14 @@ while [ "$#" != "0" ]; do
 		[ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
 			die "git checkout: branch $newbranch already exists"
 		git-check-ref-format "heads/$newbranch" ||
-			die "we do not like '$newbranch' as a branch name."
+			die "git checkout: we do not like '$newbranch' as a branch name."
 		;;
 	"-f")
 		force=1
 		;;
+	-m)
+		merge=1
+		;;
 	--)
 		break
 		;;
@@ -71,9 +75,15 @@ done
 
 if test "$#" -ge 1
 then
-	if test '' != "$newbranch$force"
+	hint=
+	if test "$#" -eq 1
+	then
+		hint="
+Did you intend to checkout '$@' which can not be resolved as commit?"
+	fi
+	if test '' != "$newbranch$force$merge"
 	then
-		die "updating paths and switching branches or forcing are incompatible."
+		die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
 	fi
 	if test '' != "$new"
 	then
@@ -113,7 +123,8 @@ fi
 
 [ -z "$branch$newbranch" ] &&
 	[ "$new" != "$old" ] &&
-	die "git checkout: you need to specify a new branch name"
+	die "git checkout: to checkout the requested commit you need to specify 
+              a name for a new branch which is created and switched to"
 
 if [ "$force" ]
 then
@@ -121,7 +132,51 @@ then
 	git-checkout-index -q -f -u -a
 else
     git-update-index --refresh >/dev/null
-    git-read-tree -m -u $old $new
+    merge_error=$(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 --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."
+	else
+	    git merge-index -o git-merge-one-file -a
+	fi
+
+	# 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
+    )
+    saved_err=$?
+    if test "$saved_err" = 0
+    then
+	test "$new" = "$old" || git diff-index --name-status "$new"
+    fi
+    (exit $saved_err)
 fi
 
 #