[SPARK-14282][SQL] CodeFormatter should handle oneline comment with /* */ properly

## What changes were proposed in this pull request?

This PR improves `CodeFormatter` to fix the following malformed indentations.
```java
/* 019 */   public java.lang.Object apply(java.lang.Object _i) {
/* 020 */     InternalRow i = (InternalRow) _i;
/* 021 */     /* createexternalrow(if (isnull(input[0, double])) null else input[0, double], if (isnull(input[1, int])) null else input[1, int], ... */
/* 022 */       boolean isNull = false;
/* 023 */       final Object[] values = new Object[2];
/* 024 */       /* if (isnull(input[0, double])) null else input[0, double] */
/* 025 */     /* isnull(input[0, double]) */
...
/* 053 */     if (!false && false) {
/* 054 */       /* null */
/* 055 */     final int value9 = -1;
/* 056 */     isNull6 = true;
/* 057 */     value6 = value9;
/* 058 */   } else {
...
/* 077 */   return mutableRow;
/* 078 */ }
/* 079 */ }
/* 080 */
```

After this PR, the code will be formatted like the following.
```java
/* 019 */   public java.lang.Object apply(java.lang.Object _i) {
/* 020 */     InternalRow i = (InternalRow) _i;
/* 021 */     /* createexternalrow(if (isnull(input[0, double])) null else input[0, double], if (isnull(input[1, int])) null else input[1, int], ... */
/* 022 */     boolean isNull = false;
/* 023 */     final Object[] values = new Object[2];
/* 024 */     /* if (isnull(input[0, double])) null else input[0, double] */
/* 025 */     /* isnull(input[0, double]) */
...
/* 053 */     if (!false && false) {
/* 054 */       /* null */
/* 055 */       final int value9 = -1;
/* 056 */       isNull6 = true;
/* 057 */       value6 = value9;
/* 058 */     } else {
...
/* 077 */     return mutableRow;
/* 078 */   }
/* 079 */ }
/* 080 */
```

Also, this issue fixes the following too. (Similar with [SPARK-14185](https://issues.apache.org/jira/browse/SPARK-14185))
```java
16/03/30 12:39:24 DEBUG WholeStageCodegen: /* 001 */ public Object generate(Object[] references) {
/* 002 */   return new GeneratedIterator(references);
/* 003 */ }
```
```java
16/03/30 12:46:32 DEBUG WholeStageCodegen:
/* 001 */ public Object generate(Object[] references) {
/* 002 */   return new GeneratedIterator(references);
/* 003 */ }
```

## How was this patch tested?

Pass the Jenkins tests (including new CodeFormatterSuite testcases.)

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #12072 from dongjoon-hyun/SPARK-14282.

3 files changed, 17 insertions, 2 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatter.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatter.scala
index 8e40754dc3..ab4831f7ab 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatter.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatter.scala
@@ -74,7 +74,8 @@ private class CodeFormatter {
         // Handle single line comments
         newIndentLevel = indentLevel
       }
-    } else {
+    }
+    if (inCommentBlock) {
       if (line.endsWith("*/")) {
         inCommentBlock = false
         newIndentLevel = indentLevelOutsideCommentBlock
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatterSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatterSuite.scala
index d7836aa3b2..f57b82bb96 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatterSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeFormatterSuite.scala
@@ -115,6 +115,20 @@ class CodeFormatterSuite extends SparkFunSuite {
     """.stripMargin
   }
 
+  testCase("single line comments /* */ ") {
+    """/** This is a comment about class A { { { ( ( */
+      |class A {
+      |class body;
+      |}""".stripMargin
+  }{
+    """
+      |/* 001 */ /** This is a comment about class A { { { ( ( */
+      |/* 002 */ class A {
+      |/* 003 */   class body;
+      |/* 004 */ }
+    """.stripMargin
+  }
+
   testCase("multi-line comments") {
     """  /* This is a comment about
       |class A {
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/WholeStageCodegen.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/WholeStageCodegen.scala
index da3ee46b7d..6a779abd40 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/WholeStageCodegen.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/WholeStageCodegen.scala
@@ -337,7 +337,7 @@ case class WholeStageCodegen(child: SparkPlan) extends UnaryNode with CodegenSup
 
     // try to compile, helpful for debug
     val cleanedSource = CodeFormatter.stripExtraNewLines(source)
-    logDebug(s"${CodeFormatter.format(cleanedSource)}")
+    logDebug(s"\n${CodeFormatter.format(cleanedSource)}")
     CodeGenerator.compile(cleanedSource)
     (ctx, cleanedSource)
   }