Merge remote-tracking branch 'origin/master' into SPARK-21646

# Conflicts:
#	sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala

sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala

@@ -2659,6 +2659,25 @@ class SQLQuerySuite extends QueryTest with SharedSQLContext {
     }
   }
 
+  test("SPARK-21743: top-most limit should not cause memory leak") {
+    // In unit test, Spark will fail the query if memory leak detected.
+    spark.range(100).groupBy("id").count().limit(1).collect()
+  }
+
+  test("SPARK-21652: rule confliction of InferFiltersFromConstraints and ConstantPropagation") {
+    withTempView("t1", "t2") {
+      Seq((1, 1)).toDF("col1", "col2").createOrReplaceTempView("t1")
+      Seq(1, 2).toDF("col").createOrReplaceTempView("t2")
+      val df = sql(
+        """
+          |SELECT *
+          |FROM t1, t2
+          |WHERE t1.col1 = 1 AND 1 = t1.col2 AND t1.col1 = t2.col AND t1.col2 = t2.col
+        """.stripMargin)
+      checkAnswer(df, Row(1, 1, 1))
+    }
+  }
+
   test("SPARK-21646: CommonTypeForBinaryComparison: StringType vs NumericType") {
     withTempView("v") {
       val str1 = Long.MaxValue.toString + "1"