[HOTFIX] [SPARK-3400] Revert 9b225ac "fix GraphX EdgeRDD zipPartitions"

9b225ac has been causing GraphX tests
to fail nondeterministically, which is blocking development for others.

Author: Ankur Dave <[email protected]>

Closes apache#2271 from ankurdave/SPARK-3400 and squashes the following commits:

10c2a97 [Ankur Dave] [HOTFIX] [SPARK-3400] Revert 9b225ac "fix GraphX EdgeRDD zipPartitions"

Author: ankurdave

graphx/src/main/scala/org/apache/spark/graphx/EdgeRDD.scala

@@ -19,7 +19,7 @@ package org.apache.spark.graphx
 
 import scala.reflect.{classTag, ClassTag}
 
-import org.apache.spark._
+import org.apache.spark.{OneToOneDependency, Partition, Partitioner, TaskContext}
 import org.apache.spark.rdd.RDD
 import org.apache.spark.storage.StorageLevel
 
@@ -55,7 +55,7 @@ class EdgeRDD[@specialized ED: ClassTag, VD: ClassTag](
    * partitioner that allows co-partitioning with `partitionsRDD`.
    */
   override val partitioner =
-    partitionsRDD.partitioner.orElse(Some(new HashPartitioner(partitionsRDD.partitions.size)))
+    partitionsRDD.partitioner.orElse(Some(Partitioner.defaultPartitioner(partitionsRDD)))
 
   override def compute(part: Partition, context: TaskContext): Iterator[Edge[ED]] = {
     val p = firstParent[(PartitionID, EdgePartition[ED, VD])].iterator(part, context)

graphx/src/test/scala/org/apache/spark/graphx/GraphSuite.scala

@@ -19,7 +19,6 @@ package org.apache.spark.graphx
 
 import org.scalatest.FunSuite
 
-import org.apache.spark.SparkConf
 import org.apache.spark.SparkContext
 import org.apache.spark.graphx.Graph._
 import org.apache.spark.graphx.PartitionStrategy._
@@ -351,19 +350,4 @@ class GraphSuite extends FunSuite with LocalSparkContext {
     }
   }
 
-  test("non-default number of edge partitions") {
-    val n = 10
-    val defaultParallelism = 3
-    val numEdgePartitions = 4
-    assert(defaultParallelism != numEdgePartitions)
-    val conf = new SparkConf()
-      .set("spark.default.parallelism", defaultParallelism.toString)
-    val sc = new SparkContext("local", "test", conf)
-    val edges = sc.parallelize((1 to n).map(x => (x: VertexId, 0: VertexId)),
-      numEdgePartitions)
-    val graph = Graph.fromEdgeTuples(edges, 1)
-    val neighborAttrSums = graph.mapReduceTriplets[Int](
-      et => Iterator((et.dstId, et.srcAttr)), _ + _)
-    assert(neighborAttrSums.collect.toSet === Set((0: VertexId, n)))
-  }
 }