GitHub user gatorsmile opened a pull request:

    https://github.com/apache/spark/pull/14042

    [SPARK-16329] [SQL] [Backport-1.6] Star Expansion over Table Containing No 
Column #14040

    #### What changes were proposed in this pull request?
    Star expansion over a table containing zero column does not work since 1.6. 
However, it works in Spark 1.5.1. This PR is to fix the issue in the master 
branch.
    
    For example, 
    ```scala
    val rddNoCols = sqlContext.sparkContext.parallelize(1 to 10).map(_ => 
Row.empty)
    val dfNoCols = sqlContext.createDataFrame(rddNoCols, StructType(Seq.empty))
    dfNoCols.registerTempTable("temp_table_no_cols")
    sqlContext.sql("select * from temp_table_no_cols").show
    ```
    
    Without the fix, users will get the following the exception:
    ```
    java.lang.IllegalArgumentException: requirement failed
            at scala.Predef$.require(Predef.scala:221)
            at 
org.apache.spark.sql.catalyst.analysis.UnresolvedStar.expand(unresolved.scala:199)
    ```
    
    #### How was this patch tested?
    Tests are added

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/gatorsmile/spark starExpansionEmpty

Alternatively you can review and apply these changes as the patch at:

    https://github.com/apache/spark/pull/14042.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #14042
    
----
commit edeeb1421931963affbd5402301563579b00611a
Author: gatorsmile <gatorsm...@gmail.com>
Date:   2016-07-04T05:09:24Z

    backport to 1.6

----


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