Minor changes

bin/pyspark

@@ -25,7 +25,7 @@ export SPARK_HOME="$FWDIR"
 
 SCALA_VERSION=2.10
 
-if [[ "$@" = *--help ]] || [[ "$@" = *--h ]]; then
+if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
   echo "Usage: ./bin/pyspark [options]"
   ./bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
   exit 0

bin/spark-shell

@@ -28,7 +28,7 @@ esac
 # Enter posix mode for bash
 set -o posix
 
-if [[ "$@" = *--help ]] || [[ "$@" = *--h ]]; then
+if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
   echo "Usage: ./bin/spark-shell [options]"
   ./bin/spark-submit --help 2>&1 | grep -v Usage 1>&2
   exit 0

core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala

@@ -334,11 +334,10 @@ object SparkSubmit {
    * no files, into a single comma-separated string.
    */
   private[spark] def mergeFileLists(lists: String*): String = {
-    lists
-      .filter(_ != null)
-      .filter(_ != "")
-      .flatMap(_.split(","))
-      .mkString(",")
+    val merged = lists.filter(_ != null)
+                      .flatMap(_.split(","))
+                      .mkString(",")
+    if (merged == "") null else merged
   }
 }