Simplified sed wrapper

helpers/config

@@ -146,7 +146,7 @@ rm /CurrentlyBuilding
 umount /proc
 }
 
-sedhelper(){
+sedhelper2(){
   FILE="$1"
   EXPR="$2"";"
 
@@ -164,6 +164,19 @@ sedhelper(){
   done
 }
 
+sedhelper(){
+  FILE="$1"
+  EXPR="$2"
+
+  MD5=$(md5sum "$FILE")
+  echo Running modification-aware sed: sed "$EXPR" -i "$FILE"
+  /bin/sed "$EXPR" -i "$FILE"
+  if [ "$MD5" = "$(md5sum "$FILE")" ]; then
+    echo File "$FILE" was not modified, stopping.
+    exit 1
+  fi
+}
+
 sed (){
 if ! echo $@ | grep -qw '\-i'; then
   echo Running fallback sed: /bin/sed "$@"