Add -r <svn revision> option

git-lkgr

 #!/bin/bash
 
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 force_branch=no
 quiet=no
+svn_lkgr=
 
 while [ $# -gt 0 ]; do
   case "$1" in
     --force-branch)
       force_branch=yes
       ;;
     -q|--quiet)
       quiet=yes
       ;;
+    -r|--revision)
+      svn_lkgr="$2"
+      shift
+      ;;
     *)
       echo "Unknown option: $1"
       ;;
   esac
   shift
 done
 
-svn_lkgr=`curl -s http://chromium-status.appspot.com/lkgr`
-if [ $? != 0 -o -z "$svn_lkgr" ]; then
-  echo 'Could not get svn lkgr from chromium-status.appspot.com/lkgr'
-  exit 1
+if [ -z "$svn_lkgr" ]; then
+  svn_lkgr=`curl -s http://chromium-status.appspot.com/lkgr`
+  if [ $? != 0 -o -z "$svn_lkgr" ]; then
+    echo 'Could not get svn lkgr from chromium-status.appspot.com/lkgr'
+    exit 1
+  fi
+fi
+
+if [ "${svn_lkgr:0:1}" = "r" ]; then
+  svn_lkgr="${svn_lkgr:1}"
 fi
 
 # Run a trivial git-svn command to force it to update the revision cache
 # (which causes spew that might otherwise confuse the next command).
 git svn info > /dev/null
 if [ $? != 0 ]; then
   cat <<EOF 1>&2
 Could not run a trivial git-svn command.  You probably need to set up your
 working directory for git-svn, by following these instructions:
 
 http://code.google.com/p/chromium/wiki/UsingNewGit#Initial_checkout
 EOF
   exit 1
 fi
 
 git_lkgr=`git svn find-rev r${svn_lkgr}`
 if [ $? != 0 -o -z "$git_lkgr" ]; then
   cat <<EOF 1>&2
 Could not map svn revision ${svn_lkgr} to a git commit.
 You may need to `git fetch` and try again.
 EOF
   exit 1
 fi
 
 set -o pipefail
 closest_commit=`git rev-list --ancestry-path \
     --grep='SVN changes up to revision [0-9]*' \
     ${git_lkgr}..refs/remotes/origin/master | tail -1`
 if [ $? != 0 -o -z "$closest_commit" ]; then
-  cat <<EOF 1>&2
-Could not find a blessed git commit (with accurate .DEPS.git and submodules)
-after svn lkgr revision $svn_lkgr.
+  closest_commit=
+  closest_svn_commit=
+else
+  closest_svn_commit=`git rev-list -n 1 ${closest_commit}^1`
+  if [ $? != 0 -o -z "$closest_svn_commit" ]; then
+    cat <<EOF 1>&2
+  I am thoroughly confused.  Please file a bug report at http://new.crbug.com.
 EOF
-  exit 1
-fi
-
-closest_svn_commit=`git rev-list -n 1 ${closest_commit}^1`
-if [ $? != 0 -o -z "$closest_svn_commit" ]; then
-  cat <<EOF 1>&2
-I am thoroughly confused.  Please file a bug report at http://new.crbug.com.
-EOF
-  exit 1
+    exit 1
+  fi
 fi
 
 # Pick a name for the new branch.  Use `git rev-parse` to make sure the branch
 # doesn't already exist; if it does, iterate an integer suffix to uniquify it.
 lkgr_branch="git_lkgr_r${svn_lkgr}"
 digit=1
 git rev-parse --verify -q "${lkgr_branch}" >/dev/null
 while [ $? -eq 0 ]; do
   lkgr_branch="git_lkgr_r${svn_lkgr}_${digit}"
   digit=`expr $digit + 1`
   git rev-parse --verify -q "${lkgr_branch}" >/dev/null
 done
 
 if [ "${closest_svn_commit}" = "${git_lkgr}" ]; then
   echo "${closest_commit}"
   if [ "$force_branch" = "yes" ]; then
     git checkout -b "${lkgr_branch}" "${closest_commit}"
   fi
   exit 0
 elif [ "${quiet}" = "yes" ]; then
   exit 1
 elif [ "${force_branch}" = "no" ]; then
-  cat <<EOF
-There is no master commit which corresponds exactly to lkgr.
-The closest commit is ${closest_commit}.
-EOF
-  read -n 1 -p 'Would you like to create a new branch based on lkgr? (y/N) '
+  echo "There is no master commit which corresponds exactly to svn revision ${svn_lkgr}."
+  if [ -n "$closest_commit" ]; then
+    echo "The closest commit is ${closest_commit}."
+  fi
+  read -n 1 -p "Would you like to create a new branch based on r${svn_lkgr}? (y/N) "
   echo
   if [ "x$REPLY" != "xy" -a "x$REPLY" != "xY" ]; then
     exit 0
   fi
 fi
 
 current_head=`git branch | grep '^\*' | cut -c3-`
 if [ "${current_head}" = "(no branch)" ]; then
   current_head=`git rev-parse HEAD`
 fi
@@ skipping 20 matching lines @@
   exit 1
 fi
 
 cat <<EOF
 
 --------------------------------------------------------------------------------
 The new branch "$lkgr_branch" was branched from this commit:
 
 $git_lkgr
 
-... which maps to the svn lkgr commit r${svn_lkgr}.  The new branch
+... which maps to the svn commit r${svn_lkgr}.  The new branch
 has one additional commit, to bring .DEPS.git, .gitmodules, and the
 invisible git submodule files up to date with DEPS.
 
 To create a working branch, do this:
 
 \$ git branch --track my_new_branch $lkgr_branch
 
 'git-cl upload' will do the right thing, i.e., it will cherry-pick all
 your changes from my_new_branch, but *not* the .DEPS.git+.gitmodules+submodules
 commit on $lkgr_branch.
 --------------------------------------------------------------------------------
 
 EOF