fix(android): Skip dist fallback when release has no version code

CHANGELOG.md

@@ -18,6 +18,8 @@
 - Keep UI profiling running when `startProfiler` is called before a requested stop takes effect at the end of the current chunk ([#6291](https://github.com/getsentry/sentry-java/pull/6291))
   - Before, the start call was ignored and the profiler still stopped at the end of the chunk, even in `TRACE` mode while sampled spans were active. On API 34 and lower, every later profile also stopped after one chunk.
 - Refuse to send data to servers whose certificate was issued by one of the leaked eMudhra intermediates (CVE-2026-111943) ([#6336](https://github.com/getsentry/sentry-java/pull/6336))
+- Stop sending the whole release as `dist` on ANR and app-exit events when the release has no `+versionCode` ([#6450](https://github.com/getsentry/sentry-java/pull/6450))
+  - Relay rejected these values (e.g. `invalid character '@'`). `dist` is now left empty unless `options.dist` is set or the release contains a version code.
 
 ### Dependencies
 

sentry-android-core/src/main/java/io/sentry/android/core/ApplicationExitInfoEventProcessor.java

@@ -532,16 +532,13 @@ private void setDist(
       event.setDist(getLaunchOption(DIST_FILENAME, String.class, options.getDist(), optionsSource));
     }
     // if there's no user-set dist, fall back to versionCode from the release string
+    // (package@versionName+versionCode). Releases without a versionCode leave dist empty.
     if (event.getDist() == null) {
       final String release = event.getRelease();
       if (release != null) {
-        try {
-          final String versionCode = release.substring(release.indexOf('+') + 1);
-          event.setDist(versionCode);
-        } catch (Throwable e) {
-          options
-              .getLogger()
-              .log(SentryLevel.WARNING, "Failed to parse release from scope cache: %s", release);
+        final int versionCodeSeparator = release.indexOf('+');
+        if (versionCodeSeparator != -1) {
+          event.setDist(release.substring(versionCodeSeparator + 1));
         }
       }
     }

sentry-android-core/src/test/java/io/sentry/android/core/ApplicationExitInfoEventProcessorTest.kt

@@ -746,6 +746,32 @@ class ApplicationExitInfoEventProcessorTest {
     assertEquals("232", processed!!.dist)
   }
 
+  @Test
+  fun `if dist is not persisted and release has no version code, leaves dist empty`() {
+    val hint = HintUtils.createWithTypeCheckHint(BackfillableHint())
+
+    val processor = fixture.getSut(tmpDir)
+    fixture.persistOptions(RELEASE_FILENAME, "io.sentry.samples@1.2")
+
+    val processed = processor.process(SentryEvent(), hint)
+
+    assertEquals("io.sentry.samples@1.2", processed!!.release)
+    assertNull(processed.dist)
+  }
+
+  @Test
+  fun `if dist is not persisted and options release has no version code, leaves dist empty`() {
+    val hint = HintUtils.createWithTypeCheckHint(AbnormalExitHint(timestamp = 2_000))
+    val processor = fixture.getSut(tmpDir)
+    fixture.options.release = "io.sentry.samples@1.2"
+    setLastUpdateTime(1_000)
+
+    val processed = processor.process(SentryEvent(), hint)!!
+
+    assertEquals("io.sentry.samples@1.2", processed.release)
+    assertNull(processed.dist)
+  }
+
   @Test
   fun `merges user`() {
     val hint = HintUtils.createWithTypeCheckHint(BackfillableHint())