Cause cros_workon to die rather than clobber local_manifest

cros_workon

 #!/bin/bash
 
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script moves ebuilds between 'stable' and 'live' states.
 # By default 'stable' ebuilds point at and build from source at the
 # last known good commit. Moving an ebuild to 'live' (via cros_workon start)
 # is intended to support development. The current source tip is fetched,
@@ skipping 130 matching lines @@
   echo "Unable to find .repo directory. Did you checkout with repo?"
   exit 1
 }
 
 
 # This is called only for "cros-workon start". We dont handle the "stop" case since the local changes are ignored anyway since the 9999.ebuild is masked and we dont want to deal with what to do with the user's local changes.
 regen_manifest_and_sync() {
   find_repo_dir
   local_manifest="${REPODIR}/local_manifest.xml"
 
+  # ensure we don't clobber existing manifest entries
+  if [ -f "${local_manifest}" ]; then
+      grep -q -i "<remote" "${local_manifest}"
+      if [ $? -ne 1 ]; then
+          die "Your local manifest will be clobbered running cros_workon. You can not have any <remote> tags at all."
+      fi
+      sed -ne '/^[[:space:]]\+[^[:space:]]/q1' "${local_manifest}"
+      if [ $? -ne 0 ]; then
+          die "Your local manifest will be clobbered running cros_workon. You can not have any tags that span multiple lines or are indented."
+      fi
+      egrep -q "^[^<]" "${local_manifest}" 
+      if [ $? -ne 1 ]; then
+          die "Your local manifest will be clobbered running cros_workon. You can not have any tags that span multiple lines"
+      fi
+      grep -v "<project" "${local_manifest}" | grep -q -i "<project" 
+      if [ $? -eq 0 ]; then
+          die "Your local manifest has mixed case tags for project.  You can not have mixed case tags"
+      fi
+  fi
   # preserve old manifest entries
   [ -f "${local_manifest}" ] && \
     MANIFEST_ENTRIES_OLD=$(cat "${local_manifest}" | grep "^<project")
 
   rm -f "${local_manifest}"
 
   # get new manifest entries
   MANIFEST_ENTRIES=$(show_live_ebuilds |
   {
     while read line
@@ skipping 77 matching lines @@
   esac
 fi
 
 case ${WORKON_CMD} in
   start)  ebuild_to_live "${ATOM_LIST}"; regen_manifest_and_sync ;;
   stop)   ebuild_to_stable "${ATOM_LIST}" ;;
   list)   [ ${FLAGS_all} = "${FLAGS_FALSE}" ] && show_live_ebuilds || show_workon_ebuilds ;;
   iterate)ebuild_iterate "${ATOM_LIST}" ;;
   *)      die "$(basename $0): command '${WORKON_CMD}' not recognized" ;;
 esac