[SPARK-19832][SQL] DynamicPartitionWriteTask get partitionPath should escape the partition name

## What changes were proposed in this pull request?

Currently in DynamicPartitionWriteTask, when we get the paritionPath of a parition, we just escape the partition value, not escape the partition name.

this will cause some problems for some  special partition name situation, for example :
1) if the partition name contains '%' etc,  there will be two partition path created in the filesytem, one is for escaped path like '/path/a%25b=1', another is for unescaped path like '/path/a%b=1'.
and the data inserted stored in unescaped path, while the show partitions table will return 'a%25b=1' which the partition name is escaped. So here it is not consist. And I think the data should be stored in the escaped path in filesystem, which Hive2.0.0 also have the same action.

2) if the partition name contains ':', there will throw exception that new Path("/path","a:b"), this is illegal which has a colon in the relative path.

```
java.lang.IllegalArgumentException: java.net.URISyntaxException: Relative path in absolute URI: a:b
  at org.apache.hadoop.fs.Path.initialize(Path.java:205)
  at org.apache.hadoop.fs.Path.<init>(Path.java:171)
  at org.apache.hadoop.fs.Path.<init>(Path.java:88)
  ... 48 elided
Caused by: java.net.URISyntaxException: Relative path in absolute URI: a:b
  at java.net.URI.checkPath(URI.java:1823)
  at java.net.URI.<init>(URI.java:745)
  at org.apache.hadoop.fs.Path.initialize(Path.java:202)
  ... 50 more
```
## How was this patch tested?
unit test added

Author: windpiger <songjun@outlook.com>

Closes #17173 from windpiger/fixDatasourceSpecialCharPartitionName.

2 files changed, 24 insertions, 1 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/FileFormatWriter.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/FileFormatWriter.scala
index 950e5ca0d6..30a09a9ad3 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/FileFormatWriter.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/FileFormatWriter.scala
@@ -341,7 +341,7 @@ object FileFormatWriter extends Logging {
           Seq(Cast(c, StringType, Option(desc.timeZoneId))),
           Seq(StringType))
         val str = If(IsNull(c), Literal(ExternalCatalogUtils.DEFAULT_PARTITION_NAME), escaped)
-        val partitionName = Literal(c.name + "=") :: str :: Nil
+        val partitionName = Literal(ExternalCatalogUtils.escapePathName(c.name) + "=") :: str :: Nil
         if (i == 0) partitionName else Literal(Path.SEPARATOR) :: partitionName
       }
     }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
index 6ffa58bcd9..b2199fdf90 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
@@ -1995,6 +1995,29 @@ class DDLSuite extends QueryTest with SharedSQLContext with BeforeAndAfterEach {
     }
   }
 
+  Seq("a b", "a:b", "a%b", "a,b").foreach { specialChars =>
+    test(s"data source table:partition column name containing $specialChars") {
+      withTable("t") {
+        withTempDir { dir =>
+          spark.sql(
+            s"""
+               |CREATE TABLE t(a string, `$specialChars` string)
+               |USING parquet
+               |PARTITIONED BY(`$specialChars`)
+               |LOCATION '$dir'
+             """.stripMargin)
+
+          assert(dir.listFiles().isEmpty)
+          spark.sql(s"INSERT INTO TABLE t PARTITION(`$specialChars`=2) SELECT 1")
+          val partEscaped = s"${ExternalCatalogUtils.escapePathName(specialChars)}=2"
+          val partFile = new File(dir, partEscaped)
+          assert(partFile.listFiles().length >= 1)
+          checkAnswer(spark.table("t"), Row("1", "2") :: Nil)
+        }
+      }
+    }
+  }
+
   Seq("a b", "a:b", "a%b").foreach { specialChars =>
     test(s"location uri contains $specialChars for datasource table") {
       withTable("t", "t1") {