[SPARK-25301][SQL] When a view uses an UDF from a non default database, Spark analyser throws AnalysisException

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/parser/AstBuilder.scala

@@ -1311,7 +1311,10 @@ class AstBuilder(conf: SQLConf) extends SqlBaseBaseVisitor[AnyRef] with Logging
   protected def visitFunctionName(ctx: QualifiedNameContext): FunctionIdentifier = {
     ctx.identifier().asScala.map(_.getText) match {
       case Seq(db, fn) => FunctionIdentifier(fn, Option(db))
-      case Seq(fn) => FunctionIdentifier(fn, None)
+      case Seq(fn) => fn.split('.').toSeq match {
+        case Seq(d, f) => FunctionIdentifier(f, Option(d))
+        case _ => FunctionIdentifier(fn, None)
+      }
       case other => throw new ParseException(s"Unsupported function name '${ctx.getText}'", ctx)
     }
   }

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveDDLSuite.scala

@@ -2281,4 +2281,23 @@ class HiveDDLSuite
       }
     }
   }
+
+  test("SPARK-25301: checks view with udf from non default database") {
+    val db = "d1"
+    withDatabase(db) {
+      spark.sql(s"CREATE DATABASE $db")
+      val table = "t1"
+      withTable(s"$db.$table") {
+        spark.sql(s"CREATE TABLE $db.$table AS SELECT 'abcd' c1, 'xyz' c2")
+        val functionNameUpper = "udfUpper"
+        withUserDefinedFunction(s"$db.$functionNameUpper" -> false) {
+          val functionClass =
+            classOf[org.apache.hadoop.hive.ql.udf.generic.GenericUDFUpper].getCanonicalName
+          sql(s"CREATE FUNCTION $db.$functionNameUpper AS '$functionClass'")
+          val ds = sql(s"SELECT `$db.$functionNameUpper`(`$table`.`c1`)  FROM `$db`.`$table`")
+          checkAnswer(ds, Row("ABCD"))
+        }
+      }
+    }
+  }
 }