Don't rely on default locale when using toUpperCase() and toLowerCase()

Otherwise these methods may produce unexpected results if used for
strings that are intended to be interpreted locale independently.
Examples are programming language identifiers, protocol keys, and HTML
tags. For instance, "TITLE".toLowerCase() in a Turkish locale returns
"t\u0131tle", where '\u0131' is the LATIN SMALL LETTER DOTLESS I
character.

See
https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#toLowerCase--
http://blog.thetaphi.de/2012/07/default-locales-default-charsets-and.html

Bug: 511238
Change-Id: Id8d8f37d84d62239c918b81f8d883ed798d87656
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

18 files changed, 52 insertions, 25 deletions

diff --git a/org.eclipse.jgit.lfs.server/src/org/eclipse/jgit/lfs/server/s3/SignerV4.java b/org.eclipse.jgit.lfs.server/src/org/eclipse/jgit/lfs/server/s3/SignerV4.java
index f95b605c85..4149484c8c 100644
--- a/org.eclipse.jgit.lfs.server/src/org/eclipse/jgit/lfs/server/s3/SignerV4.java
+++ b/org.eclipse.jgit.lfs.server/src/org/eclipse/jgit/lfs/server/s3/SignerV4.java
@@ -57,6 +57,7 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.SimpleTimeZone;
 import java.util.SortedMap;
@@ -247,7 +248,7 @@ class SignerV4 {
 		for (String header : sortedHeaders) {
 			if (buffer.length() > 0)
 				buffer.append(";"); //$NON-NLS-1$
-			buffer.append(header.toLowerCase());
+			buffer.append(header.toLowerCase(Locale.ROOT));
 		}
 
 		return buffer.toString();
@@ -265,7 +266,8 @@ class SignerV4 {
 
 		StringBuilder buffer = new StringBuilder();
 		for (String key : sortedHeaders) {
-			buffer.append(key.toLowerCase().replaceAll("\\s+", " ") + ":" //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+			buffer.append(
+					key.toLowerCase(Locale.ROOT).replaceAll("\\s+", " ") + ":" //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 					+ headers.get(key).replaceAll("\\s+", " ")); //$NON-NLS-1$//$NON-NLS-2$
 			buffer.append("\n"); //$NON-NLS-1$
 		}
diff --git a/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java
index 435a2a3c39..68dcf806b8 100644
--- a/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java
+++ b/org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java
@@ -57,6 +57,7 @@ import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Locale;
 
 import org.eclipse.jgit.junit.JGitTestUtil;
 import org.eclipse.jgit.lfs.errors.InvalidLongObjectIdException;
@@ -152,7 +153,7 @@ public class LongObjectIdTest {
 	public void test011_toString() {
 		final String x = "0123456789ABCDEFabcdef01234567890123456789ABCDEFabcdef0123456789";
 		final LongObjectId oid = LongObjectId.fromString(x);
-		assertEquals(x.toLowerCase(), oid.name());
+		assertEquals(x.toLowerCase(Locale.ROOT), oid.name());
 	}
 
 	@Test
diff --git a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsPointer.java b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsPointer.java
index 0aee1aadde..0f62025be5 100644
--- a/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsPointer.java
+++ b/org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/LfsPointer.java
@@ -51,6 +51,7 @@ import java.io.PrintStream;
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 import java.nio.charset.UnsupportedCharsetException;
+import java.util.Locale;
 
 import org.eclipse.jgit.annotations.Nullable;
 import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
@@ -79,7 +80,7 @@ public class LfsPointer {
 	 * evaluate to "sha256"
 	 */
 	public static final String HASH_FUNCTION_NAME = Constants.LONG_HASH_FUNCTION
-			.toLowerCase().replace("-", ""); //$NON-NLS-1$ //$NON-NLS-2$
+			.toLowerCase(Locale.ROOT).replace("-", ""); //$NON-NLS-1$ //$NON-NLS-2$
 
 	private AnyLongObjectId oid;
 
diff --git a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java
index 62e77285b9..82c401ff86 100644
--- a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java
+++ b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java
@@ -53,6 +53,7 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 
@@ -102,8 +103,8 @@ class Log extends RevWalkTextBuiltin {
 
 	@Option(name = "--date", usage = "usage_date")
 	void dateFormat(String date) {
-		if (date.toLowerCase().equals(date))
-			date = date.toUpperCase();
+		if (date.toLowerCase(Locale.ROOT).equals(date))
+			date = date.toUpperCase(Locale.ROOT);
 		dateFormatter = new GitDateFormatter(Format.valueOf(date));
 	}
 
diff --git a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java
index a0f4d06d40..7d111ffccb 100644
--- a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java
+++ b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java
@@ -53,6 +53,7 @@ import java.net.URL;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 
 import org.eclipse.jgit.awtui.AwtAuthenticator;
 import org.eclipse.jgit.awtui.AwtCredentialsProvider;
@@ -240,7 +241,8 @@ public class Main {
 		}
 
 		if (version) {
-			String cmdId = Version.class.getSimpleName().toLowerCase();
+			String cmdId = Version.class.getSimpleName()
+					.toLowerCase(Locale.ROOT);
 			subcommand = CommandCatalog.get(cmdId).create();
 		}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdTest.java
index 80ece1c26a..0adea0baa7 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectIdTest.java
@@ -49,6 +49,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Locale;
+
 import org.eclipse.jgit.errors.InvalidObjectIdException;
 import org.junit.Test;
 
@@ -122,7 +124,7 @@ public class ObjectIdTest {
 	public void test011_toString() {
 		final String x = "0123456789ABCDEFabcdef1234567890abcdefAB";
 		final ObjectId oid = ObjectId.fromString(x);
-		assertEquals(x.toLowerCase(), oid.name());
+		assertEquals(x.toLowerCase(Locale.ROOT), oid.name());
 	}
 
 	@Test(expected = InvalidObjectIdException.class)
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
index cc5870ebfe..a60bb39cea 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
@@ -85,6 +85,7 @@ import java.security.Security;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Locale;
 import java.util.Properties;
 import java.util.Set;
 import java.util.TreeSet;
@@ -461,7 +462,7 @@ public class WalkEncryptionTest {
 			Set<String> source = Security.getAlgorithms("Cipher");
 			Set<String> target = new TreeSet<String>();
 			for (String algo : source) {
-				algo = algo.toUpperCase();
+				algo = algo.toUpperCase(Locale.ROOT);
 				if (algo.matches(regex)) {
 					target.add(algo);
 				}
@@ -759,7 +760,7 @@ public class WalkEncryptionTest {
 			for (String source : cipherSet) {
 				// Standard names are not case-sensitive.
 				// http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html
-				String target = algorithm.toUpperCase();
+				String target = algorithm.toUpperCase(Locale.ROOT);
 				if (source.equalsIgnoreCase(target)) {
 					return true;
 				}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/MergeCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/MergeCommand.java
index ced1863719..2daa0d1a3b 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/MergeCommand.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/MergeCommand.java
@@ -50,6 +50,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 import org.eclipse.jgit.api.MergeResult.MergeStatus;
@@ -134,7 +135,7 @@ public class MergeCommand extends GitCommand<MergeResult> {
 		FF_ONLY;
 
 		public String toConfigValue() {
-			return "--" + name().toLowerCase().replace('_', '-'); //$NON-NLS-1$
+			return "--" + name().toLowerCase(Locale.ROOT).replace('_', '-'); //$NON-NLS-1$
 		}
 
 		public boolean matchConfigValue(String in) {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java
index 0388acbbaf..16315a5b55 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileRepository.java
@@ -55,6 +55,7 @@ import java.io.IOException;
 import java.text.MessageFormat;
 import java.text.ParseException;
 import java.util.HashSet;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;
 
@@ -342,7 +343,7 @@ public class FileRepository extends Repository {
 		if (symLinks != null)
 			cfg.setString(ConfigConstants.CONFIG_CORE_SECTION, null,
 					ConfigConstants.CONFIG_KEY_SYMLINKS, symLinks.name()
-							.toLowerCase());
+							.toLowerCase(Locale.ROOT));
 		cfg.setInt(ConfigConstants.CONFIG_CORE_SECTION, null,
 				ConfigConstants.CONFIG_KEY_REPO_FORMAT_VERSION, 0);
 		cfg.setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null,
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java
index 8fe8a96e99..ec771a24f0 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java
@@ -58,6 +58,7 @@ import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
@@ -895,7 +896,7 @@ public class Config {
 		if (value instanceof ConfigEnum)
 			n = ((ConfigEnum) value).toConfigValue();
 		else
-			n = value.name().toLowerCase().replace('_', ' ');
+			n = value.name().toLowerCase(Locale.ROOT).replace('_', ' ');
 		setString(section, subsection, name, n);
 	}
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/patch/FormatError.java b/org.eclipse.jgit/src/org/eclipse/jgit/patch/FormatError.java
index 245b3ee599..767cb24306 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/patch/FormatError.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/patch/FormatError.java
@@ -43,6 +43,8 @@
 
 package org.eclipse.jgit.patch;
 
+import java.util.Locale;
+
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.util.RawParseUtils;
 
@@ -102,7 +104,7 @@ public class FormatError {
 	@Override
 	public String toString() {
 		final StringBuilder r = new StringBuilder();
-		r.append(getSeverity().name().toLowerCase());
+		r.append(getSeverity().name().toLowerCase(Locale.ROOT));
 		r.append(": at offset "); //$NON-NLS-1$
 		r.append(getOffset());
 		r.append(": "); //$NON-NLS-1$
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FooterKey.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FooterKey.java
index 319b819a79..36965f4996 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FooterKey.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FooterKey.java
@@ -43,6 +43,8 @@
 
 package org.eclipse.jgit.revwalk;
 
+import java.util.Locale;
+
 import org.eclipse.jgit.lib.Constants;
 
 /** Case insensitive key for a {@link FooterLine}. */
@@ -68,7 +70,7 @@ public final class FooterKey {
 	 */
 	public FooterKey(final String keyName) {
 		name = keyName;
-		raw = Constants.encode(keyName.toLowerCase());
+		raw = Constants.encode(keyName.toLowerCase(Locale.ROOT));
 	}
 
 	/** @return name of this footer line. */
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/submodule/SubmoduleWalk.java b/org.eclipse.jgit/src/org/eclipse/jgit/submodule/SubmoduleWalk.java
index 5b9e8d9029..a10f3d7117 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/submodule/SubmoduleWalk.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/submodule/SubmoduleWalk.java
@@ -45,6 +45,7 @@ package org.eclipse.jgit.submodule;
 import java.io.File;
 import java.io.IOException;
 import java.text.MessageFormat;
+import java.util.Locale;
 
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheIterator;
@@ -663,7 +664,8 @@ public class SubmoduleWalk implements AutoCloseable {
 				ConfigConstants.CONFIG_KEY_IGNORE);
 		if (name == null)
 			return null;
-		return IgnoreSubmoduleMode.valueOf(name.trim().toUpperCase());
+		return IgnoreSubmoduleMode
+				.valueOf(name.trim().toUpperCase(Locale.ROOT));
 	}
 
 	/**
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/HttpAuthMethod.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/HttpAuthMethod.java
index 81e6904bff..4256fe47db 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/HttpAuthMethod.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/HttpAuthMethod.java
@@ -56,6 +56,7 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Random;
@@ -168,7 +169,8 @@ abstract class HttpAuthMethod {
 									SCHEMA_NAME_SEPARATOR, 2);
 
 							try {
-								Type methodType = Type.valueOf(valuePart[0].toUpperCase());
+								Type methodType = Type.valueOf(
+										valuePart[0].toUpperCase(Locale.ROOT));
 
 								if ((ignoreTypes != null)
 										&& (ignoreTypes.contains(methodType))) {
@@ -540,7 +542,7 @@ abstract class HttpAuthMethod {
 			GSSManager gssManager = GSS_MANAGER_FACTORY.newInstance(conn
 					.getURL());
 			String host = conn.getURL().getHost();
-			String peerName = "HTTP@" + host.toLowerCase(); //$NON-NLS-1$
+			String peerName = "HTTP@" + host.toLowerCase(Locale.ROOT); //$NON-NLS-1$
 			try {
 				GSSName gssName = gssManager.createName(peerName,
 						GSSName.NT_HOSTBASED_SERVICE);
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/NetRC.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/NetRC.java
index bacab7e21e..8855f96567 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/NetRC.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/NetRC.java
@@ -48,6 +48,7 @@ import java.io.FileReader;
 import java.io.IOException;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 import java.util.TreeMap;
 import java.util.regex.Matcher;
@@ -230,7 +231,7 @@ public class NetRC {
 
 				matcher.reset(line);
 				while (matcher.find()) {
-					String command = matcher.group().toLowerCase();
+					String command = matcher.group().toLowerCase(Locale.ROOT);
 					if (command.startsWith("#")) { //$NON-NLS-1$
 						matcher.reset(""); //$NON-NLS-1$
 						continue;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportGitSsh.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportGitSsh.java
index da98e8c9ea..6bdf905e4f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportGitSsh.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportGitSsh.java
@@ -56,6 +56,7 @@ import java.util.Collections;
 import java.util.EnumSet;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 
 import org.eclipse.jgit.errors.NoRemoteRepositoryException;
@@ -217,11 +218,12 @@ public class TransportGitSsh extends SshTransport implements PackTransport {
 		public Process exec(String command, int timeout)
 				throws TransportException {
 			String ssh = SystemReader.getInstance().getenv("GIT_SSH"); //$NON-NLS-1$
-			boolean putty = ssh.toLowerCase().contains("plink"); //$NON-NLS-1$
+			boolean putty = ssh.toLowerCase(Locale.ROOT).contains("plink"); //$NON-NLS-1$
 
 			List<String> args = new ArrayList<String>();
 			args.add(ssh);
-			if (putty && !ssh.toLowerCase().contains("tortoiseplink")) //$NON-NLS-1$
+			if (putty
+					&& !ssh.toLowerCase(Locale.ROOT).contains("tortoiseplink")) //$NON-NLS-1$
 				args.add("-batch"); //$NON-NLS-1$
 			if (0 < getURI().getPort()) {
 				args.add(putty ? "-P" : "-p"); //$NON-NLS-1$ //$NON-NLS-2$
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkEncryption.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkEncryption.java
index 4c3fdd84f2..333e09d463 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkEncryption.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkEncryption.java
@@ -52,6 +52,7 @@ import java.security.GeneralSecurityException;
 import java.security.spec.AlgorithmParameterSpec;
 import java.security.spec.KeySpec;
 import java.text.MessageFormat;
+import java.util.Locale;
 import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -192,7 +193,7 @@ abstract class WalkEncryption {
 
 			// Standard names are not case-sensitive.
 			// http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html
-			String cryptoName = cryptoAlg.toUpperCase();
+			String cryptoName = cryptoAlg.toUpperCase(Locale.ROOT);
 
 			if (!cryptoName.startsWith("PBE")) //$NON-NLS-1$
 				throw new GeneralSecurityException(JGitText.get().encryptionOnlyPBE);
@@ -373,7 +374,7 @@ abstract class WalkEncryption {
 
 			SecretKey keyBase = factory.generateSecret(keySpec);
 
-			String name = cipherAlgo.toUpperCase();
+			String name = cipherAlgo.toUpperCase(Locale.ROOT);
 			Matcher matcherPBE = Pattern.compile(REGEX_PBE).matcher(name);
 			Matcher matcherTrans = Pattern.compile(REGEX_TRANS).matcher(name);
 			if (matcherPBE.matches()) {
@@ -506,7 +507,7 @@ abstract class WalkEncryption {
 		JGitV1(String algo, String pass)
 				throws GeneralSecurityException {
 			super(wrap(algo, pass));
-			String name = cipherAlgo.toUpperCase();
+			String name = cipherAlgo.toUpperCase(Locale.ROOT);
 			Matcher matcherPBE = Pattern.compile(REGEX_PBE).matcher(name);
 			if (!matcherPBE.matches())
 				throw new GeneralSecurityException(
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/FileUtils.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/FileUtils.java
index aa101f73f9..c04dfa9610 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/FileUtils.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/FileUtils.java
@@ -65,6 +65,7 @@ import java.text.Normalizer;
 import java.text.Normalizer.Form;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.regex.Pattern;
 
 import org.eclipse.jgit.internal.JGitText;
@@ -542,7 +543,8 @@ public class FileUtils {
 	public static boolean isStaleFileHandle(IOException ioe) {
 		String msg = ioe.getMessage();
 		return msg != null
-				&& msg.toLowerCase().matches("stale .*file .*handle"); //$NON-NLS-1$
+				&& msg.toLowerCase(Locale.ROOT)
+						.matches("stale .*file .*handle"); //$NON-NLS-1$
 	}
 
 	/**