1 files changed, 90 insertions, 6 deletions
diff --git a/git-reset-script b/git-reset-script
index 7da8d8682..863e2a997 100755
--- a/git-reset-script
+++ b/git-reset-script
@@ -1,13 +1,97 @@
 #!/bin/sh
 . git-sh-setup-script || die "Not a git archive"
+
+tmp=/var/tmp/reset.$$
+trap 'rm -f $tmp-*' 0 1 2 3 15
+
+reset_type=--mixed
+case "$1" in
+--mixed | --soft | --hard)
+	reset_type="$1"
+	shift
+	;;
+esac
+
 rev=$(git-rev-parse --verify --default HEAD "$@") || exit
 rev=$(git-rev-parse --verify $rev^0) || exit
-git-read-tree --reset "$rev" && {
-	if orig=$(git-rev-parse --verify HEAD 2>/dev/null)
+
+# We need to remember the set of paths that _could_ be left
+# behind before a hard reset, so that we can remove them.
+if test "$reset_type" = "--hard"
+then
+	{
+		git-ls-files --stage -z
+		git-rev-parse --verify HEAD 2>/dev/null &&
+		git-ls-tree -r -z HEAD
+	} | perl -e '
+	    use strict;
+	    my %seen;
+	    $/ = "\0";
+	    while (<>) {
+		chomp;
+		my ($info, $path) = split(/\t/, $_);
+		next if ($info =~ / tree /);
+		if (!$seen{$path}) {
+			$seen{$path} = 1;
+			print "$path\0";
+		}
+	    }
+	' >$tmp-exists
+fi
+
+# Soft reset does not touch the index file nor the working tree
+# at all, but requires them in a good order.  Other resets reset
+# the index file to the tree object we are switching to.
+if test "$reset_type" = "--soft"
+then
+	if test -f "$GIT_DIR/MERGE_HEAD" ||
+	   test "" != "$(git-ls-files --unmerged)"
 	then
-		echo "$orig" >"$GIT_DIR/ORIG_HEAD"
+		die "Cannot do a soft reset in the middle of a merge."
 	fi
-	echo "$rev" > "$GIT_DIR/HEAD"
-}
-git-update-cache --refresh
+else
+	git-read-tree --reset "$rev" || exit
+fi
+
+# Any resets update HEAD to the head being switched to.
+if orig=$(git-rev-parse --verify HEAD 2>/dev/null)
+then
+	echo "$orig" >"$GIT_DIR/ORIG_HEAD"
+else
+	rm -f "$GIT_DIR/ORIG_HEAD"
+fi
+echo "$rev" >"$GIT_DIR/HEAD"
+
+case "$reset_type" in
+--hard )
+	# Hard reset matches the working tree to that of the tree
+	# being switched to.
+	git-checkout-cache -f -u -q -a
+	git-ls-files --cached -z |
+	perl -e '
+		use strict;
+		my (%keep, $fh);
+		$/ = "\0";
+		while (<STDIN>) {
+			chomp;
+			$keep{$_} = 1;
+		}
+		open $fh, "<", $ARGV[0]
+			or die "cannot open $ARGV[0]";
+		while (<$fh>) {
+			chomp;
+			if (! exists $keep{$_}) {
+				print "$_\0";
+			}
+		}
+	' $tmp-exists | xargs -0 rm -v -f --
+	;;
+--soft )
+	;; # Nothing else to do
+--mixed )
+	# Report what has not been updated.
+	git-update-cache --refresh
+	;;
+esac
+
 rm -f "$GIT_DIR/MERGE_HEAD"