-# Set up GIT_DIR and GIT_OBJECT_DIRECTORY
-# and return true if everything looks ok
-#
-: ${GIT_DIR=.git}
-: ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}
+# This is included in commands that either have to be run from the toplevel
+# of the repository, or with GIT_DIR environment variable properly.
+# If the GIT_DIR does not look like the right correct git-repository,
+# it dies.
+
+# Having this variable in your environment would break scripts because
+# you would cause "cd" to be be taken to unexpected places. If you
+# like CDPATH, define it for your interactive shell sessions without
+# exporting it.
+unset CDPATH