Review feedback. And fix spark-submit on Windows.

Author: Marcelo Vanzin

bin/spark-class

@@ -41,8 +41,7 @@ else
 fi
 
 # Look for the launcher. In non-release mode, add the compiled classes directly to the classpath
-# instead of looking for a jar file, since it's very common for people using sbt to use the
-# "assembly" target instead of "package".
+# instead of looking for a jar file.
 SPARK_LAUNCHER_CP=
 if [ -f $SPARK_HOME/RELEASE ]; then
   LAUNCHER_DIR="$SPARK_HOME/lib"
@@ -72,8 +71,9 @@ else
   SPARK_LAUNCHER_CP="$LAUNCHER_DIR/classes"
 fi
 
-# The launcher library will print arguments separated by a NULL character. Read that in a while
-# loop, populating an array that will be used to exec the final command.
+# The launcher library will print arguments separated by a NULL character, to allow arguments with
+# characters that would be otherwise interpreted by the shell. Read that in a while loop, populating
+# an array that will be used to exec the final command.
 CMD=()
 while IFS= read -d '' -r ARG; do
   CMD+=("$ARG")

bin/spark-class2.cmd

@@ -62,6 +62,8 @@ rem Figure out where java is.
 set RUNNER=java
 if not "x%JAVA_HOME%"=="x" set RUNNER=%JAVA_HOME%\bin\java
 
+rem The launcher library prints the command to be executed in a single line suitable for being
+rem executed by the batch interpreter. So read all the output of the launcher into a variable.
 for /f "tokens=*" %%i in ('cmd /C ""%RUNNER%" -cp %LAUNCHER_CP% org.apache.spark.launcher.Main %*"') do (
   set SPARK_CMD=%%i
 )

bin/spark-submit.cmd

@@ -20,4 +20,4 @@ rem
 rem This is the entry point for running Spark submit. To avoid polluting the
 rem environment, it just launches a new cmd to do the real work.
 
-cmd /V /E /C %~dp0spark-submit2.cmd %*
+cmd /V /E /C %~dp0spark-class2.cmd org.apache.spark.deploy.SparkSubmit %*