Use numbered capture groups for sentry-trace validation (#4652)

* Use numbered capture groups for sentry-trace validation

* Fix tab escape in character gropu and add tests

* Use previous tab escape

* Add changelog entry

* Fix typo

---------

Co-authored-by: markushi <[email protected]>

Author: alexander-alderman-webb

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+### Fixes
+
+- Do not use named capturing groups for regular expressions ([#4652](https://github.com/getsentry/sentry-java/pull/4652))
+  - This fixes a crash on Android versions below 8.0 (API level 26)
+
 ### Features
 
 - Add onDiscard to enable users to track the type and amount of data discarded before reaching Sentry ([#4612](https://github.com/getsentry/sentry-java/pull/4612))

sentry/src/main/java/io/sentry/SentryTraceHeader.java

@@ -15,10 +15,10 @@ public final class SentryTraceHeader {
   private final @NotNull SpanId spanId;
   private final @Nullable Boolean sampled;
 
+  // Use numbered capture groups for Android API level < 26 compatibility
   private static final Pattern SENTRY_TRACEPARENT_HEADER_REGEX =
       Pattern.compile(
-          "^[ \\t]*(?<traceId>[0-9a-f]{32})-(?<spanId>[0-9a-f]{16})(?<sampled>-[01])?[ \\t]*$",
-          Pattern.CASE_INSENSITIVE);
+          "^[ \\t]*([0-9a-f]{32})-([0-9a-f]{16})(-[01])?[ \\t]*$", Pattern.CASE_INSENSITIVE);
 
   public SentryTraceHeader(
       final @NotNull SentryId traceId,
@@ -33,14 +33,15 @@ public SentryTraceHeader(final @NotNull String value) throws InvalidSentryTraceH
     Matcher matcher = SENTRY_TRACEPARENT_HEADER_REGEX.matcher(value);
     boolean matchesExist = matcher.matches();
 
-    if (!matchesExist || matcher.group("traceId") == null || matcher.group("spanId") == null) {
+    if (!matchesExist) {
       throw new InvalidSentryTraceHeaderException(value);
     }
 
-    this.traceId = new SentryId(matcher.group("traceId"));
-    this.spanId = new SpanId(matcher.group("spanId"));
-    this.sampled =
-        matcher.group("sampled") == null ? null : "1".equals(matcher.group("sampled").substring(1));
+    this.traceId = new SentryId(matcher.group(1));
+    this.spanId = new SpanId(matcher.group(2));
+
+    String sampled = matcher.group(3);
+    this.sampled = sampled == null ? null : "1".equals(sampled.substring(1));
   }
 
   public @NotNull String getName() {

sentry/src/test/java/io/sentry/SentryTraceHeaderTest.kt

@@ -132,6 +132,26 @@ class SentryTraceHeaderTest {
     assertNull(header.isSampled)
   }
 
+  @Test
+  fun `handles header without sampling decision and leading whitespace`() {
+    val sentryId = SentryId()
+    val spanId = SpanId()
+    val header = SentryTraceHeader(" \t $sentryId-$spanId")
+    assertEquals(sentryId, header.traceId)
+    assertEquals(spanId, header.spanId)
+    assertNull(header.isSampled)
+  }
+
+  @Test
+  fun `handles header without sampling decision and trailing whitespace`() {
+    val sentryId = SentryId()
+    val spanId = SpanId()
+    val header = SentryTraceHeader("$sentryId-$spanId \t ")
+    assertEquals(sentryId, header.traceId)
+    assertEquals(spanId, header.spanId)
+    assertNull(header.isSampled)
+  }
+
   @Test
   fun `when sampling decision is not made, getValue returns header with traceId and spanId`() {
     val sentryId = SentryId()