Use 'git svn find-rev' in git-svnrevert instead of shell script fu.

Thanks Chandler!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180592 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/utils/git-svn/git-svnrevert b/utils/git-svn/git-svnrevert
index de4ff1cd4663a85fc96134a0d0b113cd2168016c..06a9c440915f1e26261def374fd48e8b4c0daba7 100755 (executable)
--- a/utils/git-svn/git-svnrevert
+++ b/utils/git-svn/git-svnrevert
@@ -14,10 +14,9 @@ fi
 
 COMMIT=$1
 
-SVN_REVISION=$(git log -1 $COMMIT | grep git-svn-id | tr -s "@" " " | cut -f 4 -d " ")
-
-if [ -z "$SVN_REVISION" ]; then
-    echo "Error! Given commit is not a git-svn revision!"
+SVN_REVISION=$(git svn find-rev "$COMMIT")
+if [ $? -ne 0 ]; then
+    echo "Error! Could not find an svn revision for commit $COMMIT!"
     exit 1
 fi