fix: replace @SuppressWarnings with Locale.ROOT in test classes

Replace remaining @SuppressWarnings("StringCaseLocaleUsage") with
explicit Locale.ROOT in 6 test files. The suppress annotations were
hiding real locale-sensitivity bugs:

- BytecodeCompiler: toUpperCase() on opcode names like "jumpi" would
  produce "JUMPİ" on Turkish locale, causing opcode lookup failure
- ShieldedReceiveTest: toUpperCase() on ztron address containing 'i'
  would produce 'İ' instead of 'I', breaking address decoding
- CronExpressionTest, OperationsTest, DataWord, SM2KeyTest: hex
  formatting with toUpperCase() (low risk but inconsistent)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: halibobo1205

framework/src/test/java/org/tron/common/cron/CronExpressionTest.java

@@ -24,6 +24,7 @@
 import java.text.ParseException;
 import java.util.Calendar;
 import java.util.Date;
+import java.util.Locale;
 import org.junit.Test;
 
 public class CronExpressionTest {
@@ -161,12 +162,11 @@ public void testLastDayOffset() throws Exception {
 
   }
 
-  @SuppressWarnings("StringCaseLocaleUsage")
   @Test
   public void testQuartz() throws Exception {
     CronExpression cronExpression = new CronExpression("19 15 10 4 Apr ? ");
-    assertEquals("19 15 10 4 Apr ? ".toUpperCase(), cronExpression.getCronExpression());
-    assertEquals("19 15 10 4 Apr ? ".toUpperCase(), cronExpression.toString());
+    assertEquals("19 15 10 4 Apr ? ".toUpperCase(Locale.ROOT), cronExpression.getCronExpression());
+    assertEquals("19 15 10 4 Apr ? ".toUpperCase(Locale.ROOT), cronExpression.toString());
 
     // if broken, this will throw an exception
     cronExpression.getNextValidTimeAfter(new Date());

framework/src/test/java/org/tron/common/crypto/SM2KeyTest.java

@@ -13,6 +13,7 @@
 import java.security.KeyPairGenerator;
 import java.security.SignatureException;
 import java.util.Arrays;
+import java.util.Locale;
 import lombok.extern.slf4j.Slf4j;
 import org.bouncycastle.crypto.digests.SM3Digest;
 import org.bouncycastle.util.encoders.Hex;
@@ -116,15 +117,14 @@ public void testInvalidSignatureLength() throws SignatureException {
     fail("Expecting a SignatureException for invalid signature length");
   }
 
-  @SuppressWarnings("StringCaseLocaleUsage")
   @Test
   public void testSM3Hash() {
     SM2 key = SM2.fromPublicOnly(pubKey);
     SM2Signer signer = key.getSM2SignerForHash();
     String message = "message digest";
     byte[] hash = signer.generateSM3Hash(message.getBytes());
     assertEquals("2A723761EAE35429DF643648FD69FB7787E7FC32F321BFAF7E294390F529BAF4",
-        Hex.toHexString(hash).toUpperCase());
+        Hex.toHexString(hash).toUpperCase(Locale.ROOT));
   }
 
 

framework/src/test/java/org/tron/common/runtime/vm/BytecodeCompiler.java

@@ -2,6 +2,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 
 import org.bouncycastle.util.encoders.Hex;
 import org.tron.core.vm.Op;
@@ -12,13 +13,12 @@ public byte[] compile(String code) {
     return compile(code.split("\\s+"));
   }
 
-  @SuppressWarnings("StringCaseLocaleUsage")
   private byte[] compile(String[] tokens) {
     List<Byte> bytecodes = new ArrayList<>();
     int ntokens = tokens.length;
 
     for (String s : tokens) {
-      String token = s.trim().toUpperCase();
+      String token = s.trim().toUpperCase(Locale.ROOT);
 
       if (token.isEmpty()) {
         continue;

framework/src/test/java/org/tron/common/runtime/vm/OperationsTest.java

@@ -5,6 +5,7 @@
 import static org.tron.core.config.Parameter.ChainConstant.FROZEN_PERIOD;
 
 import java.util.List;
+import java.util.Locale;
 import java.util.Random;
 
 import lombok.SneakyThrows;
@@ -489,7 +490,6 @@ public void testBlockInformationOperations() throws ContractValidateException {
   }
 
   // test Memory, Storage and Flow Operations
-  @SuppressWarnings("StringCaseLocaleUsage")
   @Test
   public void testMemoryStorageAndFlowOperations() throws ContractValidateException {
     invoke = new ProgramInvokeMockImpl();
@@ -539,7 +539,7 @@ public void testMemoryStorageAndFlowOperations() throws ContractValidateExceptio
     testSingleOperation(program);
     Assert.assertEquals(20, program.getResult().getEnergyUsed());
     Assert.assertEquals("00000000000000000000000000000000000000000000000000000000000000CC",
-        Hex.toHexString(program.getStack().peek().getData()).toUpperCase());
+        Hex.toHexString(program.getStack().peek().getData()).toUpperCase(Locale.ROOT));
 
     // PC = 0x58
     op = new byte[]{0x60, 0x01, 0x60, 0x00, 0x58};
@@ -819,7 +819,6 @@ public void testOtherOperations() throws ContractValidateException {
     Assert.assertTrue(program.getResult().isRevert());
   }
 
-  @SuppressWarnings("StringCaseLocaleUsage")
   @Ignore
   @Test
   public void testComplexOperations() throws ContractValidateException {
@@ -863,7 +862,7 @@ public void testComplexOperations() throws ContractValidateException {
     testSingleOperation(program);
     Assert.assertEquals(10065, program.getResult().getEnergyUsed());
     Assert.assertEquals("0000000000000000000000000000000000000000000000000000000000000033",
-        Hex.toHexString(program.getStack().peek().getData()).toUpperCase());
+        Hex.toHexString(program.getStack().peek().getData()).toUpperCase(Locale.ROOT));
 
     // EXTCODESIZE = 0x3b
     op = new byte[]{0x3b};
@@ -883,7 +882,7 @@ public void testComplexOperations() throws ContractValidateException {
     testSingleOperation(program);
     Assert.assertEquals(38, program.getResult().getEnergyUsed());
     Assert.assertEquals("6000600000000000000000000000000000000000000000000000000000000000",
-        Hex.toHexString(program.getMemory()).toUpperCase());
+        Hex.toHexString(program.getMemory()).toUpperCase(Locale.ROOT));
 
   }
 

framework/src/test/java/org/tron/common/utils/client/utils/DataWord.java

@@ -24,6 +24,7 @@
 import com.fasterxml.jackson.annotation.JsonValue;
 import java.math.BigInteger;
 import java.nio.ByteBuffer;
+import java.util.Locale;
 
 import org.bouncycastle.util.Arrays;
 import org.bouncycastle.util.encoders.Hex;
@@ -430,9 +431,8 @@ public String toPrefixString() {
     return Hex.toHexString(pref).substring(0, 6);
   }
 
-  @SuppressWarnings("StringCaseLocaleUsage")
   public String shortHex() {
-    String hexValue = Hex.toHexString(getNoLeadZeroesData()).toUpperCase();
+    String hexValue = Hex.toHexString(getNoLeadZeroesData()).toUpperCase(Locale.ROOT);
     return "0x" + hexValue.replaceFirst("^0+(?!$)", "");
   }
 

framework/src/test/java/org/tron/core/zksnark/ShieldedReceiveTest.java

@@ -12,6 +12,7 @@
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Optional;
 import java.util.Set;
 import javax.annotation.Resource;
@@ -2527,12 +2528,11 @@ public void pushSameSkAndScanAndSpend() throws Exception {
     Assert.assertTrue(ok2);
   }
 
-  @SuppressWarnings("StringCaseLocaleUsage")
   @Test
   public void decodePaymentAddressIgnoreCase() {
     String addressLower =
         "ztron1975m0wyg8f30cgf2l5fgndhzqzkzgkgnxge8cwx2wr7m3q7chsuwewh2e6u24yykum0hq8ue99u";
-    String addressUpper = addressLower.toUpperCase();
+    String addressUpper = addressLower.toUpperCase(Locale.ROOT);
 
     PaymentAddress paymentAddress1 = KeyIo.decodePaymentAddress(addressLower);
     PaymentAddress paymentAddress2 = KeyIo.decodePaymentAddress(addressUpper);