Only set executable permission on staged files if required and not set (

#1414)

When staging files, only set the target executable permission if the source file is executable and the target file is not executable.

It can be problematic if setting the executable permission on a target file multiple times if using inotify to watch staged files as inotify events will be triggered even when the permission is already set. This fix ensures the executable permission is only set once, to avoid unnecessary inotify events.

Co-authored-by: Nepomuk Seiler <muuki88@users.noreply.github.com>

src/main/scala/com/typesafe/sbt/packager/Stager.scala

@@ -30,7 +30,9 @@ object Stager {
     // TODO - Config file user-readable permissions....
     for {
       (from, to) <- copies
-      if from.canExecute
+      // Only set executable permission if it needs to be set. Note: calling to.setExecutable(true) if it's already
+      // executable is undesirable for a developer using inotify to watch this file as it will trigger events again
+      if from.canExecute && !to.canExecute
     } to.setExecutable(true)
     stageDirectory
   }