## What changes were proposed in this pull request?
A Bean serializer in `ExpressionEncoder`  could change values when Beans having NULL. A concrete example is as follows;
```
scala> :paste
class Outer extends Serializable {
  private var cls: Inner = _
  def setCls(c: Inner): Unit = cls = c
  def getCls(): Inner = cls
}

class Inner extends Serializable {
  private var str: String = _
  def setStr(s: String): Unit = str = str
  def getStr(): String = str
}

scala> Seq("""{"cls":null}""", """{"cls": {"str":null}}""").toDF().write.text("data")
scala> val encoder = Encoders.bean(classOf[Outer])
scala> val schema = encoder.schema
scala> val df = spark.read.schema(schema).json("data").as[Outer](encoder)
scala> df.show
+------+
|   cls|
+------+
|[null]|
|  null|
+------+

scala> df.map(x => x)(encoder).show()
+------+
|   cls|
+------+
|[null]|
|[null]|     // <-- Value changed
+------+
```

This is because the Bean serializer does not have the NULL-check expressions that the serializer of Scala's product types has. Actually, this value change does not happen in Scala's product types;

```
scala> :paste
case class Outer(cls: Inner)
case class Inner(str: String)

scala> val encoder = Encoders.product[Outer]
scala> val schema = encoder.schema
scala> val df = spark.read.schema(schema).json("data").as[Outer](encoder)
scala> df.show
+------+
|   cls|
+------+
|[null]|
|  null|
+------+

scala> df.map(x => x)(encoder).show()
+------+
|   cls|
+------+
|[null]|
|  null|
+------+
```

This pr added the NULL-check expressions in Bean serializer along with the serializer of Scala's product types.

## How was this patch tested?
Added tests in `JavaDatasetSuite`.

Author: Takeshi Yamamuro <yamamuro@apache.org>

Closes #17372 from maropu/SPARK-19980-BACKPORT2.1.

## What changes were proposed in this pull request?

The description in the comment for array_contains is vague/incomplete (i.e., doesn't mention that it returns `null` if the array is `null`); this PR fixes that.

## How was this patch tested?

No testing, since it merely changes a comment.

Please review http://spark.apache.org/contributing.html

 before opening a pull request.

Author: Will Manning <lwwmanning@gmail.com>

Closes #17380 from lwwmanning/patch-1.

(cherry picked from commit a04dcde8)
Signed-off-by: Reynold Xin <rxin@databricks.com>

## What changes were proposed in this pull request?

When SparkR is installed as a R package there might not be any java runtime.
If it is not there SparkR's `sparkR.session()` will block waiting for the connection timeout, hanging the R IDE/shell, without any notification or message.

## How was this patch tested?

manually

- [x] need to test on Windows

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #16596 from felixcheung/rcheckjava.

(cherry picked from commit a8877bdb)
Signed-off-by: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

## What changes were proposed in this pull request?

Change the nullability of function `StringToMap` from `false` to `true`.

Author: zhaorongsheng <334362872@qq.com>

Closes #17350 from zhaorongsheng/bug-fix_strToMap_NPE.

(cherry picked from commit 7dbc162f)
Signed-off-by: Xiao Li <gatorsmile@gmail.com>

## What changes were proposed in this pull request?

Since current `HiveShim`'s `convertFilters` does not escape the string literals. There exists the following correctness issues. This PR aims to return the correct result and also shows the more clear exception message.

**BEFORE**

```scala
scala> Seq((1, "p1", "q1"), (2, "p1\" and q=\"q1", "q2")).toDF("a", "p", "q").write.partitionBy("p", "q").saveAsTable("t1")

scala> spark.table("t1").filter($"p" === "p1\" and q=\"q1").select($"a").show
+---+
|  a|
+---+
+---+

scala> spark.table("t1").filter($"p" === "'\"").select($"a").show
java.lang.RuntimeException: Caught Hive MetaException attempting to get partition metadata by filter from ...
```

**AFTER**

```scala
scala> spark.table("t1").filter($"p" === "p1\" and q=\"q1").select($"a").show
+---+
|  a|
+---+
|  2|
+---+

scala> spark.table("t1").filter($"p" === "'\"").select($"a").show
java.lang.UnsupportedOperationException: Partition filter cannot have both `"` and `'` characters
```

## How was this patch tested?

Pass the Jenkins test with new test cases.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #17266 from dongjoon-hyun/SPARK-19912.

(cherry picked from commit 21e366ae)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

(Jira: https://issues.apache.org/jira/browse/SPARK-17204

)

## What changes were proposed in this pull request?

There are a couple of bugs in the `BlockManager` with respect to support for replicated off-heap storage. First, the locally-stored off-heap byte buffer is disposed of when it is replicated. It should not be. Second, the replica byte buffers are stored as heap byte buffers instead of direct byte buffers even when the storage level memory mode is off-heap. This PR addresses both of these problems.

## How was this patch tested?

`BlockManagerReplicationSuite` was enhanced to fill in the coverage gaps. It now fails if either of the bugs in this PR exist.

Author: Michael Allman <michael@videoamp.com>

Closes #16499 from mallman/spark-17204-replicated_off_heap_storage.

(cherry picked from commit 7fa116f8)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

## What changes were proposed in this pull request?

For right outer join, values of the left key will be filled with nulls if it can't match the value of the right key, so `nullOrdering` of the left key can't be guaranteed. We should output right key order instead of left key order.

For full outer join, neither left key nor right key guarantees `nullOrdering`. We should not output any ordering.

In tests, besides adding three test cases for left/right/full outer sort merge join, this patch also reorganizes code in `PlannerSuite` by putting together tests for `Sort`, and also extracts common logic in Sort tests into a method.

## How was this patch tested?

Corresponding test cases are added.

Author: wangzhenhua <wangzhenhua@huawei.com>
Author: Zhenhua Wang <wzh_zju@163.com>

Closes #17331 from wzhfy/wrongOrdering.

(cherry picked from commit 965a5abc)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

## What changes were proposed in this pull request?

Passes R `tempdir()` (this is the R session temp dir, shared with other temp files/dirs) to JVM, set System.Property for derby home dir to move derby.log

## How was this patch tested?

Manually, unit tests

With this, these are relocated to under /tmp
```
# ls /tmp/RtmpG2M0cB/
derby.log
```
And they are removed automatically when the R session is ended.

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #16330 from felixcheung/rderby.

(cherry picked from commit 422aa67d)
Signed-off-by: Felix Cheung <felixcheung@apache.org>

## What changes were proposed in this pull request?

Fix scaladoc for UDFRegistration

## How was this patch tested?

local build

Author: Jacek Laskowski <jacek@japila.pl>

Closes #17337 from jaceklaskowski/udfregistration-scaladoc.

(cherry picked from commit 6326d406)
Signed-off-by: Reynold Xin <rxin@databricks.com>

## What changes were proposed in this pull request?

Sometimes, CheckpointTests will hang on a busy machine because the streaming jobs are too slow and cannot catch up. I observed the scheduled delay was keeping increasing for dozens of seconds locally.

This PR increases the batch interval from 0.5 seconds to 2 seconds to generate less Spark jobs. It should make `pyspark.streaming.tests.CheckpointTests` more stable. I also replaced `sleep` with `awaitTerminationOrTimeout` so that if the streaming job fails, it will also fail the test.

## How was this patch tested?

Jenkins

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #17323 from zsxwing/SPARK-19986.

(cherry picked from commit 376d7821)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>

## Problem

There are several places where we write out version identifiers in various logs for structured streaming (usually `v1`). However, in the places where we check for this, we throw a confusing error message.

## What changes were proposed in this pull request?

This patch made two major changes:
1. added a `parseVersion(...)` method, and based on this method, fixed the following places the way they did version checking (no other place needed to do this checking):
```
HDFSMetadataLog
  - CompactibleFileStreamLog  ------------> fixed with this patch
    - FileStreamSourceLog  ---------------> inherited the fix of `CompactibleFileStreamLog`
    - FileStreamSinkLog  -----------------> inherited the fix of `CompactibleFileStreamLog`
  - OffsetSeqLog  ------------------------> fixed with this patch
  - anonymous subclass in KafkaSource  ---> fixed with this patch
```

2. changed the type of `FileStreamSinkLog.VERSION`, `FileStreamSourceLog.VERSION` etc. from `String` to `Int`, so that we can identify newer versions via `version > 1` instead of `version != "v1"`
    - note this didn't break any backwards compatibility -- we are still writing out `"v1"` and reading back `"v1"`

## Exception message with this patch
```
java.lang.IllegalStateException: Failed to read log file /private/var/folders/nn/82rmvkk568sd8p3p8tb33trw0000gn/T/spark-86867b65-0069-4ef1-b0eb-d8bd258ff5b8/0. UnsupportedLogVersion: maximum supported log version is v1, but encountered v99. The log file was produced by a newer version of Spark and cannot be read by this version. Please upgrade.
	at org.apache.spark.sql.execution.streaming.HDFSMetadataLog.get(HDFSMetadataLog.scala:202)
	at org.apache.spark.sql.execution.streaming.OffsetSeqLogSuite$$anonfun$3$$anonfun$apply$mcV$sp$2.apply(OffsetSeqLogSuite.scala:78)
	at org.apache.spark.sql.execution.streaming.OffsetSeqLogSuite$$anonfun$3$$anonfun$apply$mcV$sp$2.apply(OffsetSeqLogSuite.scala:75)
	at org.apache.spark.sql.test.SQLTestUtils$class.withTempDir(SQLTestUtils.scala:133)
	at org.apache.spark.sql.execution.streaming.OffsetSeqLogSuite.withTempDir(OffsetSeqLogSuite.scala:26)
	at org.apache.spark.sql.execution.streaming.OffsetSeqLogSuite$$anonfun$3.apply$mcV$sp(OffsetSeqLogSuite.scala:75)
	at org.apache.spark.sql.execution.streaming.OffsetSeqLogSuite$$anonfun$3.apply(OffsetSeqLogSuite.scala:75)
	at org.apache.spark.sql.execution.streaming.OffsetSeqLogSuite$$anonfun$3.apply(OffsetSeqLogSuite.scala:75)
	at org.scalatest.Transformer$$anonfun$apply$1.apply$mcV$sp(Transformer.scala:22)
	at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
```

## How was this patch tested?

unit tests

Author: Liwei Lin <lwlin7@gmail.com>

Closes #17327 from lw-lin/good-msg-2.1.

[SPARK-19765][SPARK-18549][SPARK-19093][SPARK-19736][BACKPORT-2.1][SQL] Backport Three Cache-related PRs to Spark 2.1

### What changes were proposed in this pull request?

Backport a few cache related PRs:

---
[[SPARK-19093][SQL] Cached tables are not used in SubqueryExpression](https://github.com/apache/spark/pull/16493)

Consider the plans inside subquery expressions while looking up cache manager to make
use of cached data. Currently CacheManager.useCachedData does not consider the
subquery expressions in the plan.

---
[[SPARK-19736][SQL] refreshByPath should clear all cached plans with the specified path](https://github.com/apache/spark/pull/17064)

Catalog.refreshByPath can refresh the cache entry and the associated metadata for all dataframes (if any), that contain the given data source path.

However, CacheManager.invalidateCachedPath doesn't clear all cached plans with the specified path. It causes some strange behaviors reported in SPARK-15678.

---
[[SPARK-19765][SPARK-18549][SQL] UNCACHE TABLE should un-cache all cached plans that refer to this table](https://github.com/apache/spark/pull/17097)

When un-cache a table, we should not only remove the cache entry for this table, but also un-cache any other cached plans that refer to this table. The following commands trigger the table uncache: `DropTableCommand`, `TruncateTableCommand`, `AlterTableRenameCommand`, `UncacheTableCommand`, `RefreshTable` and `InsertIntoHiveTable`

This PR also includes some refactors:
- use java.util.LinkedList to store the cache entries, so that it's safer to remove elements while iterating
- rename invalidateCache to recacheByPlan, which is more obvious about what it does.

### How was this patch tested?
N/A

Author: Xiao Li <gatorsmile@gmail.com>

Closes #17319 from gatorsmile/backport-17097.

[SPARK-19329][SQL][BRANCH-2.1] Reading from or writing to a datasource table with a non pre-existing location should succeed

## What changes were proposed in this pull request?

This is a backport pr of https://github.com/apache/spark/pull/16672 into branch-2.1.

## How was this patch tested?
Existing tests.

Author: windpiger <songjun@outlook.com>

Closes #17317 from windpiger/backport-insertnotexists.

## What changes were proposed in this pull request?

This PR proposes to use the correct deserializer, `BatchedSerializer` for RDD construction for coalesce/repartition when the shuffle is enabled. Currently, it is passing `UTF8Deserializer` as is not `BatchedSerializer` from the copied one.

with the file, `text.txt` below:

```
a
b

d
e
f
g
h
i
j
k
l

```

- Before

```python
>>> sc.textFile('text.txt').repartition(1).collect()
```

```
UTF8Deserializer(True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File ".../spark/python/pyspark/rdd.py", line 811, in collect
    return list(_load_from_socket(port, self._jrdd_deserializer))
  File ".../spark/python/pyspark/serializers.py", line 549, in load_stream
    yield self.loads(stream)
  File ".../spark/python/pyspark/serializers.py", line 544, in loads
    return s.decode("utf-8") if self.use_unicode else s
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/utf_8.py", line 16, in decode
    return codecs.utf_8_decode(input, errors, True)
UnicodeDecodeError: 'utf8' codec can't decode byte 0x80 in position 0: invalid start byte
```

- After

```python
>>> sc.textFile('text.txt').repartition(1).collect()
```

```
[u'a', u'b', u'', u'd', u'e', u'f', u'g', u'h', u'i', u'j', u'k', u'l', u'']
```

## How was this patch tested?

Unit test in `python/pyspark/tests.py`.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17282 from HyukjinKwon/SPARK-19872.

(cherry picked from commit 7387126f)
Signed-off-by: Davies Liu <davies.liu@gmail.com>

## What changes were proposed in this pull request?
This patch moves SQLConf from sql/core to sql/catalyst. To minimize the changes, the patch used type alias to still keep CatalystConf (as a type alias) and SimpleCatalystConf (as a concrete class that extends SQLConf).

Motivation for the change is that it is pretty weird to have SQLConf only in sql/core and then we have to duplicate config options that impact optimizer/analyzer in sql/catalyst using CatalystConf.

This is a backport into branch-2.1 to minimize merge conflicts.

## How was this patch tested?
N/A

Author: Reynold Xin <rxin@databricks.com>

Closes #17301 from rxin/branch-2.1-conf.

When dynamic partition value is null or empty string, we should write the data to a directory like `a=__HIVE_DEFAULT_PARTITION__`, when we read the data back, we should respect this special directory name and treat it as null.

This is the same behavior of impala, see https://issues.apache.org/jira/browse/IMPALA-252



new regression test

Author: Wenchen Fan <wenchen@databricks.com>

Closes #17277 from cloud-fan/partition.

(cherry picked from commit dacc382f)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

## What changes were proposed in this pull request?
The `RemoveRedundantAlias` rule can change the output attributes (the expression id's to be precise) of a query by eliminating the redundant alias producing them. This is no problem for a regular query, but can cause problems for correlated subqueries: The attributes produced by the subquery are used in the parent plan; changing them will break the parent plan.

This PR fixes this by wrapping a subquery in a `Subquery` top level node when it gets optimized. The `RemoveRedundantAlias` rule now recognizes `Subquery` and makes sure that the output attributes of the `Subquery` node are retained.

## How was this patch tested?
Added a test case to `RemoveRedundantAliasAndProjectSuite` and added a regression test to `SubquerySuite`.

Author: Herman van Hovell <hvanhovell@databricks.com>

Closes #17278 from hvanhovell/SPARK-19933.

(cherry picked from commit e04c05cf)
Signed-off-by: Herman van Hovell <hvanhovell@databricks.com>

When using the KafkaSource with Structured Streaming, consumer assignments are not what the user expects if startingOffsets is set to an explicit set of topics/partitions in JSON where the topic(s) happen to have uppercase characters. When StartingOffsets is constructed, the original string value from options is transformed toLowerCase to make matching on "earliest" and "latest" case insensitive. However, the toLowerCase JSON is passed to SpecificOffsets for the terminal condition, so topic names may not be what the user intended by the time assignments are made with the underlying KafkaConsumer.

KafkaSourceProvider.scala:
```
val startingOffsets = caseInsensitiveParams.get(STARTING_OFFSETS_OPTION_KEY).map(_.trim.toLowerCase) match {
    case Some("latest") => LatestOffsets
    case Some("earliest") => EarliestOffsets
    case Some(json) => SpecificOffsets(JsonUtils.partitionOffsets(json))
    case None => LatestOffsets
  }
```

Thank cbowden for reporting.

Jenkins

Author: uncleGen <hustyugm@gmail.com>

Closes #17209 from uncleGen/SPARK-19853.

(cherry picked from commit 0a4d06a7)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

## What changes were proposed in this pull request?

- SS python example: `TypeError: 'xxx' object is not callable`
- some other doc issue.

## How was this patch tested?

Jenkins.

Author: uncleGen <hustyugm@gmail.com>

Closes #17257 from uncleGen/docs-ss-python.

(cherry picked from commit e29a74d5)
Signed-off-by: Sean Owen <sowen@cloudera.com>

Add a new configuration option that allows Spark SQL to infer a case-sensitive schema from a Hive Metastore table's data files when a case-sensitive schema can't be read from the table properties.

- Add spark.sql.hive.caseSensitiveInferenceMode param to SQLConf
- Add schemaPreservesCase field to CatalogTable (set to false when schema can't
  successfully be read from Hive table props)
- Perform schema inference in HiveMetastoreCatalog if schemaPreservesCase is
  false, depending on spark.sql.hive.caseSensitiveInferenceMode
- Add alterTableSchema() method to the ExternalCatalog interface
- Add HiveSchemaInferenceSuite tests
- Refactor and move ParquetFileForamt.meregeMetastoreParquetSchema() as
  HiveMetastoreCatalog.mergeWithMetastoreSchema
- Move schema merging tests from ParquetSchemaSuite to HiveSchemaInferenceSuite

[JIRA for this change](https://issues.apache.org/jira/browse/SPARK-19611)

The tests in ```HiveSchemaInferenceSuite``` should verify that schema inference is working as expected. ```ExternalCatalogSuite``` has also been extended to cover the new ```alterTableSchema()``` API.

Author: Budde <budde@amazon.com>

Closes #17229 from budde/SPARK-19611-2.1.

In spark SQL, map type can't be used in equality test/comparison, and `Intersect`/`Except`/`Distinct` do need equality test for all columns, we should not allow map type in `Intersect`/`Except`/`Distinct`.

new regression test

Author: Wenchen Fan <wenchen@databricks.com>

Closes #17236 from cloud-fan/map.

(cherry picked from commit fb9beda5)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

## What changes were proposed in this pull request?

We need to notify the await batch lock when the stream exits early e.g., when an exception has been thrown.

## How was this patch tested?

Current tests that throw exceptions at runtime will finish faster as a result of this update.

zsxwing

Please review http://spark.apache.org/contributing.html

 before opening a pull request.

Author: Tyson Condie <tcondie@gmail.com>

Closes #17231 from tcondie/kafka-writer.

(cherry picked from commit 501b7111)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

## What changes were proposed in this pull request?

Fix the `throw new IllegalStateException` if statement part.

## How is this patch tested

Regression test

Author: Burak Yavuz <brkyvz@gmail.com>

Closes #17228 from brkyvz/kafka-cause-fix.

(cherry picked from commit 82138e09)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

## What changes were proposed in this pull request?

`watermark` should not be negative. This behavior is invalid, check it before real run.

## How was this patch tested?

add new unit test.

Author: uncleGen <hustyugm@gmail.com>
Author: dylon <hustyugm@gmail.com>

Closes #17202 from uncleGen/SPARK-19861.

(cherry picked from commit 30b18e69)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

## What changes were proposed in this pull request?

Add handling of input of type `Int` for dataType `TimestampType` to `EvaluatePython.scala`. Py4J serializes ints smaller than MIN_INT or larger than MAX_INT to Long, which are handled correctly already, but values between MIN_INT and MAX_INT are serialized to Int.

These range limits correspond to roughly half an hour on either side of the epoch. As a result, PySpark doesn't allow TimestampType values to be created in this range.

Alternatives attempted: patching the `TimestampType.toInternal` function to cast return values to `long`, so Py4J would always serialize them to Scala Long. Python3 does not have a `long` type, so this approach failed on Python3.

## How was this patch tested?

Added a new PySpark-side test that fails without the change.

The contribution is my original work and I license the work to the project under the project’s open source license.

Resubmission of https://github.com/apache/spark/pull/16896

. The original PR didn't go through Jenkins and broke the build. davies dongjoon-hyun

cloud-fan Could you kick off a Jenkins run for me? It passed everything for me locally, but it's possible something has changed in the last few weeks.

Author: Jason White <jason.white@shopify.com>

Closes #17200 from JasonMWhite/SPARK-19561.

(cherry picked from commit 206030bd)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

## What changes were proposed in this pull request?

A follow up to SPARK-19859:

- extract the calculation of `delayMs` and reuse it.
- update EventTimeWatermarkExec
- use the correct `delayMs` in EventTimeWatermark

## How was this patch tested?

Jenkins.

Author: uncleGen <hustyugm@gmail.com>

Closes #17221 from uncleGen/SPARK-19859.

(cherry picked from commit eeb1d6db)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

## What changes were proposed in this pull request?

The API docs should not include the "org.apache.spark.sql.internal" package because they are internal private APIs.

## How was this patch tested?

Jenkins

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #17217 from zsxwing/SPARK-19874.

(cherry picked from commit 029e40b4)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

[MINOR][SQL] The analyzer rules are fired twice for cases when AnalysisException is raised from analyzer.

## What changes were proposed in this pull request?
In general we have a checkAnalysis phase which validates the logical plan and throws AnalysisException on semantic errors. However we also can throw AnalysisException from a few analyzer rules like ResolveSubquery.

I found that we fire up the analyzer rules twice for the queries that throw AnalysisException from one of the analyzer rules. This is a very minor fix. We don't have to strictly fix it. I just got confused seeing the rule getting fired two times when i was not expecting it.

## How was this patch tested?

Tested manually.

Author: Dilip Biswal <dbiswal@us.ibm.com>

Closes #17214 from dilipbiswal/analyis_twice.

(cherry picked from commit d809ceed)
Signed-off-by: Xiao Li <gatorsmile@gmail.com>

This reverts commit 502c927b.

[SPARK-19813] maxFilesPerTrigger combo latestFirst may miss old files in combination with maxFileAge in FileStreamSource

## What changes were proposed in this pull request?

**The Problem**
There is a file stream source option called maxFileAge which limits how old the files can be, relative the latest file that has been seen. This is used to limit the files that need to be remembered as "processed". Files older than the latest processed files are ignored. This values is by default 7 days.
This causes a problem when both
latestFirst = true
maxFilesPerTrigger > total files to be processed.
Here is what happens in all combinations
1) latestFirst = false - Since files are processed in order, there wont be any unprocessed file older than the latest processed file. All files will be processed.
2) latestFirst = true AND maxFilesPerTrigger is not set - The maxFileAge thresholding mechanism takes one batch initialize. If maxFilesPerTrigger is not, then all old files get processed in the first batch, and so no file is left behind.
3) latestFirst = true AND maxFilesPerTrigger is set to X - The first batch process the latest X files. That sets the threshold latest file - maxFileAge, so files older than this threshold will never be considered for processing.
The bug is with case 3.

**The Solution**

Ignore `maxFileAge` when both `maxFilesPerTrigger` and `latestFirst` are set.

## How was this patch tested?

Regression test in `FileStreamSourceSuite`

Author: Burak Yavuz <brkyvz@gmail.com>

Closes #17153 from brkyvz/maxFileAge.

(cherry picked from commit a3648b5d)
Signed-off-by: Burak Yavuz <brkyvz@gmail.com>

Previously, we were using the mirror of passed in `TypeTag` when reflecting to build an encoder.  This fails when the outer class is built in (i.e. `Seq`'s default mirror is based on root classloader) but inner classes (i.e. `A` in `Seq[A]`) are defined in the REPL or a library.

This patch changes us to always reflect based on a mirror created using the context classloader.

Author: Michael Armbrust <michael@databricks.com>

Closes #17201 from marmbrus/replSeqEncoder.

(cherry picked from commit 314e48a3)
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

## What changes were proposed in this pull request?
The `keyword_only` decorator in PySpark is not thread-safe.  It writes kwargs to a static class variable in the decorator, which is then retrieved later in the class method as `_input_kwargs`.  If multiple threads are constructing the same class with different kwargs, it becomes a race condition to read from the static class variable before it's overwritten.  See [SPARK-19348](https://issues.apache.org/jira/browse/SPARK-19348) for reproduction code.

This change will write the kwargs to a member variable so that multiple threads can operate on separate instances without the race condition.  It does not protect against multiple threads operating on a single instance, but that is better left to the user to synchronize.

## How was this patch tested?
Added new unit tests for using the keyword_only decorator and a regression test that verifies `_input_kwargs` can be overwritten from different class instances.

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #17193 from BryanCutler/pyspark-keyword_only-threadsafe-SPARK-19348-2_1.

## What changes were proposed in this pull request?

The new watermark should override the old one. Otherwise, we just pick up the first column which has a watermark, it may be unexpected.

## How was this patch tested?

The new test.

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #17199 from zsxwing/SPARK-19859.

(cherry picked from commit d8830c50)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

This reverts commit 6f468462.

Add parentheses so that both lines form a single statement; also add
a log message so that the issue becomes more explicit if it shows up
again.

Tested manually with integration test that exercises the feature.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #17198 from vanzin/SPARK-19857.

(cherry picked from commit 8e41c2ee)
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>

## What changes were proposed in this pull request?

Cast the output of `TimestampType.toInternal` to long to allow for proper Timestamp creation in DataFrames near the epoch.

## How was this patch tested?

Added a new test that fails without the change.

dongjoon-hyun davies Mind taking a look?

The contribution is my original work and I license the work to the project under the project’s open source license.

Author: Jason White <jason.white@shopify.com>

Closes #16896 from JasonMWhite/SPARK-19561.

(cherry picked from commit 6f468462)
Signed-off-by: Davies Liu <davies.liu@gmail.com>

## What changes were proposed in this pull request?

Add a new Kafka Sink and Kafka Relation for writing streaming and batch queries, respectively, to Apache Kafka.
### Streaming Kafka Sink
- When addBatch is called
-- If batchId is great than the last written batch
--- Write batch to Kafka
---- Topic will be taken from the record, if present, or from a topic option, which overrides topic in record.
-- Else ignore

### Batch Kafka Sink
- KafkaSourceProvider will implement CreatableRelationProvider
- CreatableRelationProvider#createRelation will write the passed in Dataframe to a Kafka
- Topic will be taken from the record, if present, or from topic option, which overrides topic in record.
- Save modes Append and ErrorIfExist supported under identical semantics. Other save modes result in an AnalysisException

tdas zsxwing

## How was this patch tested?

### The following unit tests will be included
- write to stream with topic field: valid stream write with data that includes an existing topic in the schema
- write structured streaming aggregation w/o topic field, with default topic: valid stream write with data that does not include a topic field, but the configuration includes a default topic
- write data with bad schema: various cases of writing data that does not conform to a proper schema e.g., 1. no topic field or default topic, and 2. no value field
- write data with valid schema but wrong types: data with a complete schema but wrong types e.g., key and value types are integers.
- write to non-existing topic: write a stream to a topic that does not exist in Kafka, which has been configured to not auto-create topics.
- write batch to kafka: simple write batch to Kafka, which goes through the same code path as streaming scenario, so validity checks will not be redone here.

### Examples
```scala
// Structured Streaming
val writer = inputStringStream.map(s => s.get(0).toString.getBytes()).toDF("value")
 .selectExpr("value as key", "value as value")
 .writeStream
 .format("kafka")
 .option("checkpointLocation", checkpointDir)
 .outputMode(OutputMode.Append)
 .option("kafka.bootstrap.servers", brokerAddress)
 .option("topic", topic)
 .queryName("kafkaStream")
 .start()

// Batch
val df = spark
 .sparkContext
 .parallelize(Seq("1", "2", "3", "4", "5"))
 .map(v => (topic, v))
 .toDF("topic", "value")

df.write
 .format("kafka")
 .option("kafka.bootstrap.servers",brokerAddress)
 .option("topic", topic)
 .save()
```
Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: Tyson Condie <tcondie@gmail.com>

Closes #17043 from tcondie/kafka-writer.

[SPARK-19822][TEST] CheckpointSuite.testCheckpointedOperation: should not filter checkpointFilesOfLatestTime with the PATH string.

## What changes were proposed in this pull request?

https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/73800/testReport/



```
sbt.ForkMain$ForkError: org.scalatest.exceptions.TestFailedDueToTimeoutException: The code
passed to eventually never returned normally. Attempted 617 times over 10.003740484 seconds.
Last failure message: 8 did not equal 2.
	at org.scalatest.concurrent.Eventually$class.tryTryAgain$1(Eventually.scala:420)
	at org.scalatest.concurrent.Eventually$class.eventually(Eventually.scala:438)
	at org.scalatest.concurrent.Eventually$.eventually(Eventually.scala:478)
	at org.scalatest.concurrent.Eventually$class.eventually(Eventually.scala:336)
	at org.scalatest.concurrent.Eventually$.eventually(Eventually.scala:478)
	at org.apache.spark.streaming.DStreamCheckpointTester$class.generateOutput(CheckpointSuite
.scala:172)
	at org.apache.spark.streaming.CheckpointSuite.generateOutput(CheckpointSuite.scala:211)
```

the check condition is:

```
val checkpointFilesOfLatestTime = Checkpoint.getCheckpointFiles(checkpointDir).filter {
     _.toString.contains(clock.getTimeMillis.toString)
}
// Checkpoint files are written twice for every batch interval. So assert that both
// are written to make sure that both of them have been written.
assert(checkpointFilesOfLatestTime.size === 2)
```

the path string may contain the `clock.getTimeMillis.toString`, like `3500` :

```
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-500
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-1000
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-1500
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-2000
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-2500
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-3000
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-3500.bk
file:/root/dev/spark/assembly/CheckpointSuite/spark-20035007-9891-4fb6-91c1-cc15b7ccaf15/checkpoint-3500
                                                       ▲▲▲▲
```

so we should only check the filename, but not the whole path.

## How was this patch tested?

Jenkins.

Author: uncleGen <hustyugm@gmail.com>

Closes #17167 from uncleGen/flaky-CheckpointSuite.

(cherry picked from commit 207067ea)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>

## What changes were proposed in this pull request?

"DataFrameCallbackSuite.execute callback functions when a DataFrame action failed" sets the log level to "fatal" but doesn't recover it. Hence, tests running after it won't output any logs except fatal logs.

This PR uses `testQuietly` instead to avoid changing the log level.

## How was this patch tested?

Jenkins

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #17156 from zsxwing/SPARK-19816.

(cherry picked from commit fbc40580)
Signed-off-by: Yin Huai <yhuai@databricks.com>