Documentation: update tutorial's discussion of origin

diff --git a/git-checkout.sh b/git-checkout.sh
index dd477245fb3703402b950cbc1378b35ce379d631..92ec069a3acacc2d12c2c709311969f3d0aa4153 100755 (executable)
--- a/git-checkout.sh
+++ b/git-checkout.sh
@@ -22,7 +22,7 @@ while [ "$#" != "0" ]; do
                shift
                [ -z "$newbranch" ] &&
                        die "git checkout: -b needs a branch name"
-               [ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
+               git-show-ref --verify --quiet -- "refs/heads/$newbranch" &&
                        die "git checkout: branch $newbranch already exists"
                git-check-ref-format "heads/$newbranch" ||
                        die "git checkout: we do not like '$newbranch' as a branch name."
@@ -51,7 +51,8 @@ while [ "$#" != "0" ]; do
                        fi
                        new="$rev"
                        new_name="$arg^0"
-                       if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
+                       if git-show-ref --verify --quiet -- "refs/heads/$arg"
+                       then
                                branch="$arg"
                        fi
                elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
@@ -76,6 +77,11 @@ while [ "$#" != "0" ]; do
     esac
 done
 
+case "$force$merge" in
+11)
+       die "git checkout: -f and -m are incompatible"
+esac
+
 # The behaviour of the command with and without explicit path
 # parameters is quite different.
 #
@@ -106,7 +112,11 @@ Did you intend to checkout '$@' which can not be resolved as commit?"
                git-ls-tree --full-name -r "$new" "$@" |
                git-update-index --index-info || exit $?
        fi
-       git-checkout-index -f -u -- "$@"
+
+       # Make sure the request is about existing paths.
+       git-ls-files --error-unmatch -- "$@" >/dev/null || exit
+       git-ls-files -- "$@" |
+       git-checkout-index -f -u --stdin
        exit $?
 else
        # Make sure we did not fall back on $arg^{tree} codepath
@@ -136,8 +146,11 @@ fi
 
 [ -z "$branch$newbranch" ] &&
        [ "$new" != "$old" ] &&
-       die "git checkout: to checkout the requested commit you need to specify 
-              a name for a new branch which is created and switched to"
+       die "git checkout: provided reference cannot be checked out directly
+
+  You need -b to associate a new branch with the wanted checkout. Example:
+  git checkout -b <new_branch_name> $arg
+"
 
 if [ "X$old" = X ]
 then
@@ -151,7 +164,7 @@ then
     git-read-tree --reset -u $new
 else
     git-update-index --refresh >/dev/null
-    merge_error=$(git-read-tree -m -u $old $new 2>&1) || (
+    merge_error=$(git-read-tree -m -u --exclude-per-directory=.gitignore $old $new 2>&1) || (
        case "$merge" in
        '')
                echo >&2 "$merge_error"
@@ -162,7 +175,8 @@ else
        git diff-files --name-only | git update-index --remove --stdin &&
        work=`git write-tree` &&
        git read-tree --reset -u $new &&
-       git read-tree -m -u --aggressive $old $new $work || exit
+       git read-tree -m -u --aggressive --exclude-per-directory=.gitignore $old $new $work ||
+       exit
 
        if result=`git write-tree 2>/dev/null`
        then