Sentry recovers after a Thread had currentHub set to a NoOpHub (#2076)

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Fixes
+
+- Sentry can now self heal after a Thread had its currentHub set to a NoOpHub ([#2076](https://github.com/getsentry/sentry-java/pull/2076))
+
 ## 6.0.0-rc.1
 
 ### Features

sentry/src/main/java/io/sentry/Sentry.java

@@ -41,7 +41,7 @@ private Sentry() {}
       return mainHub;
     }
     IHub hub = currentHub.get();
-    if (hub == null) {
+    if (hub == null || hub instanceof NoOpHub) {
       hub = mainHub.clone();
       currentHub.set(hub);
     }

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

@@ -14,8 +14,8 @@ import kotlin.test.BeforeTest
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
+import kotlin.test.assertNotNull
 import kotlin.test.assertTrue
-
 class SentryTest {
 
     private val dsn = "http://key@localhost/proj"
@@ -209,6 +209,30 @@ class SentryTest {
         assertFalse(File(sentryOptions?.profilingTracesDirPath!!).exists())
     }
 
+    @Test
+    fun `using sentry before calling init creates NoOpHub but after init Sentry uses a new clone`() {
+        // noop as not yet initialized, caches NoOpHub in ThreadLocal
+        Sentry.captureMessage("noop caused")
+
+        assertTrue(Sentry.getCurrentHub() is NoOpHub)
+
+        // init Sentry in another thread
+        val thread = Thread() {
+            Sentry.init {
+                it.dsn = dsn
+                it.isDebug = true
+            }
+        }
+        thread.start()
+        thread.join()
+
+        Sentry.captureMessage("should work now")
+
+        val hub = Sentry.getCurrentHub()
+        assertNotNull(hub)
+        assertFalse(hub is NoOpHub)
+    }
+
     private fun getTempPath(): String {
         val tempFile = Files.createTempDirectory("cache").toFile()
         tempFile.delete()