fix: ghost-fleet auto-fixes on bdu/register-mappings

- CrashUploader: fix empty experimental:{} when isExtendedInfoEnabled()=false
- CrashTrackingConfig: add private constructor to utility class
- HotspotCrashLogParser: use m.end() instead of indexOf('=') + 1
- RedactUtils: annotate redactDottedClassOopRef as @VisibleForTesting
- RedactUtils: add underscore to NMETHOD_CLASS, DOTTED_CLASS_OOP_REF, IS_AN_OOP regex character classes

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

Author: jbachorik

dd-java-agent/agent-crashtracking/src/main/java/datadog/crashtracking/CrashUploader.java

@@ -579,8 +579,9 @@ private RequestBody makeErrorTrackingRequestBody(@Nonnull CrashLog payload, bool
         // experimental
         if (payload.experimental != null
             && (payload.experimental.ucontext != null
-                || payload.experimental.registerToMemoryMapping != null
-                || payload.experimental.runtimeArgs != null)) {
+                || (uploaderSettings.isExtendedInfoEnabled()
+                    && (payload.experimental.registerToMemoryMapping != null
+                        || payload.experimental.runtimeArgs != null)))) {
           writer.name("experimental");
           writer.beginObject();
           if (payload.experimental.ucontext != null) {

dd-java-agent/agent-crashtracking/src/main/java/datadog/crashtracking/parsers/HotspotCrashLogParser.java

@@ -455,7 +455,7 @@ public CrashLog parse(String uuid, String crashLog) {
             if (m.lookingAt()) {
               currentRegisterToMemoryMapping = m.group(1);
               registerToMemoryMapping.put(
-                  currentRegisterToMemoryMapping, line.substring(line.indexOf('=') + 1));
+                  currentRegisterToMemoryMapping, line.substring(m.end()));
             } else if (!currentRegisterToMemoryMapping.isEmpty()) {
               registerToMemoryMapping.computeIfPresent(
                   currentRegisterToMemoryMapping, (key, value) -> value + "\n" + line);

dd-java-agent/agent-crashtracking/src/main/java/datadog/crashtracking/parsers/RedactUtils.java

@@ -50,7 +50,7 @@ public final class RedactUtils {
   //   "Compiled method (c2) ... com.company.Foo::methodName (N bytes)"   (PRODUCT — dots)
   //   "Compiled method (c2) ... com/company/Foo::methodName (N bytes)"   (debug  — slashes)
   private static final Pattern NMETHOD_CLASS =
-      Pattern.compile("([A-Za-z][A-Za-z0-9$]*(?:[./][A-Za-z][A-Za-z0-9$]*)+)::");
+      Pattern.compile("([A-Za-z$_][A-Za-z0-9$_]*(?:[./][A-Za-z$_][A-Za-z0-9$_]*)+)::");
 
   // Library path in two formats produced by os::print_location():
   //   <offset 0x...> in /path/to/lib.so at 0x...       (no dladdr symbol)
@@ -62,11 +62,11 @@ public final class RedactUtils {
   // This specifically identifies the inline string value of a java.lang.Class 'name' field
   private static final Pattern DOTTED_CLASS_OOP_REF =
       Pattern.compile(
-          "\"([A-Za-z][A-Za-z0-9$]*(?:\\.[A-Za-z][A-Za-z0-9$]*)*)\"(\\{0x[0-9a-fA-F]+\\})");
+          "\"([A-Za-z$_][A-Za-z0-9$_]*(?:\\.[A-Za-z$_][A-Za-z0-9$_]*)*)\"(\\{0x[0-9a-fA-F]+\\})");
 
   // is an oop: com.company.Class
   private static final Pattern IS_AN_OOP =
-      Pattern.compile("(is an oop: )([A-Za-z][A-Za-z0-9$]*(?:\\.[A-Za-z][A-Za-z0-9$]*)*)");
+      Pattern.compile("(is an oop: )([A-Za-z$_][A-Za-z0-9$_]*(?:\\.[A-Za-z$_][A-Za-z0-9$_]*)*)");
 
   // Hex-dump bytes in "points into unknown readable memory:" lines.
   // Two formats produced by os::print_location():
@@ -215,6 +215,7 @@ static String redactNmethodClass(String line) {
    * java.lang.Class} oop) use {@link #redactRegisterToMemoryMapping} which detects the oop type
    * automatically.
    */
+  // @VisibleForTesting — no production callers; used directly in unit tests
   static String redactDottedClassOopRef(String line) {
     return redactStringOopRef(line, false);
   }

dd-trace-api/src/main/java/datadog/trace/api/config/CrashTrackingConfig.java

@@ -7,6 +7,8 @@
  * documentation for details.
  */
 public final class CrashTrackingConfig {
+  private CrashTrackingConfig() {}
+
   public static final String CRASH_TRACKING_ENABLED = "crashtracking.enabled";
   public static final boolean CRASH_TRACKING_ENABLED_DEFAULT = true;