detect line number mismatches and bail out

edname.sh

@@ -26,6 +26,10 @@ execute_rename() {
   command="$1"
 
   lines="$(cat .original.edname | wc -l)"
+  if [ "$lines" != "$(cat .rename.edname | wc -l)" ] ; then
+    echo "mismatch in number of lines! not continuing. make sure no lines are added or removed!"
+    exit 1
+  fi
   IFS=$'\n' read -rd '' -a src_lines < .original.edname
   IFS=$'\n' read -rd '' -a dest_lines < .rename.edname