[SPARK-20156][CORE][SQL][STREAMING][MLLIB] Java String toLowerCase "Turkish locale bug" causes Spark problems

## What changes were proposed in this pull request?

Add Locale.ROOT to internal calls to String `toLowerCase`, `toUpperCase`, to avoid inadvertent locale-sensitive variation in behavior (aka the "Turkish locale problem").

The change looks large but it is just adding `Locale.ROOT` (the locale with no country or language specified) to every call to these methods.

## How was this patch tested?

Existing tests.

Author: Sean Owen <sowen@cloudera.com>

Closes #17527 from srowen/SPARK-20156.

1 files changed, 2 insertions, 1 deletions

diff --git a/sql/hive-thriftserver/src/main/java/org/apache/hive/service/auth/SaslQOP.java b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/auth/SaslQOP.java
index ab3ac6285a..ad4dfd75f4 100644
--- a/sql/hive-thriftserver/src/main/java/org/apache/hive/service/auth/SaslQOP.java
+++ b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/auth/SaslQOP.java
@@ -19,6 +19,7 @@
 package org.apache.hive.service.auth;
 
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 
 /**
@@ -52,7 +53,7 @@ public enum SaslQOP {
 
   public static SaslQOP fromString(String str) {
     if (str != null) {
-      str = str.toLowerCase();
+      str = str.toLowerCase(Locale.ROOT);
     }
     SaslQOP saslQOP = STR_TO_ENUM.get(str);
     if (saslQOP == null) {