Prevent registering terminating callback multiple times and incorrectly trying to finish transaction

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## 3.5.1
+
+The Sentry SDK team is happy to announce the immediate availability of Sentry Laravel SDK v3.5.1.
+
+### Bug Fixes
+
+- Prevent registering terminating callback multiple times and guard against finishing already finished transactions [(#717)](https://github.com/getsentry/sentry-laravel/pull/717)
+
+  This fixes the `Call to a member function finish() on null` that could occur when using long running processes like on the CLI or with Laravel Octane.
+
 ## 3.5.0
 
 The Sentry SDK team is happy to announce the immediate availability of Sentry Laravel SDK v3.5.0.

src/Sentry/Laravel/Tracing/Middleware.php

@@ -43,6 +43,13 @@ class Middleware
      */
     private $app;
 
+    /**
+     * Whether the terminating callback has been registered.
+     *
+     * @var bool
+     */
+    private $registeredTerminatingCallback = false;
+
     /**
      * Construct the Sentry tracing middleware.
      *
@@ -102,6 +109,11 @@ public function terminate(Request $request, $response): void
         if ($this->app === null) {
             $this->finishTransaction();
         } else {
+            // Ensure we do not register the terminating callback multiple times since there is no point in doing so
+            if ($this->registeredTerminatingCallback) {
+                return;
+            }
+
             // We need to finish the transaction after the response has been sent to the client
             // so we register a terminating callback to do so, this allows us to also capture
             // spans that are created during the termination of the application like queue
@@ -111,6 +123,8 @@ public function terminate(Request $request, $response): void
             $this->app->terminating(function () {
                 $this->finishTransaction();
             });
+
+            $this->registeredTerminatingCallback = true;
         }
     }
 
@@ -223,6 +237,13 @@ private function hydrateResponseData(SymfonyResponse $response): void
 
     private function finishTransaction(): void
     {
+        // We could end up multiple times here since we register a terminating callback so
+        // double check if we have a transaction before trying to finish it since it could
+        // have already been finished in between being registered and being executed again
+        if ($this->transaction === null) {
+            return;
+        }
+
         // Make sure we set the transaction and not have a child span in the Sentry SDK
         // If the transaction is not on the scope during finish, the trace.context is wrong
         SentrySdk::getCurrentHub()->setSpan($this->transaction);