fix(react): Avoid multiple name updates on navigation spans

Author: onurtemizkan

packages/react/src/reactrouterv6-compat-utils.tsx

@@ -518,21 +518,42 @@ export function handleNavigation(opts: {
     }
 
     const activeSpan = getActiveSpan();
-    const isAlreadyInNavigationSpan = activeSpan && spanToJSON(activeSpan).op === 'navigation';
+    const rootSpan = activeSpan ? getRootSpan(activeSpan) : undefined;
+    const isAlreadyInNavigationSpan = rootSpan && spanToJSON(rootSpan).op === 'navigation';
 
     // Cross usage can result in multiple navigation spans being created without this check
     if (isAlreadyInNavigationSpan) {
-      activeSpan?.updateName(name);
-      activeSpan?.setAttribute(SEMANTIC_ATTRIBUTE_SENTRY_SOURCE, source);
+      // Check if we've already set the name for this span using a custom property
+      const hasBeenNamed = (
+        rootSpan as {
+          __sentry_navigation_name_set__?: boolean;
+        }
+      )?.__sentry_navigation_name_set__;
+      if (!hasBeenNamed) {
+        // This is the first time we're setting the name for this span
+        const spanJson = spanToJSON(rootSpan);
+        if (!spanJson.timestamp) {
+          rootSpan?.updateName(name);
+          rootSpan?.setAttribute(SEMANTIC_ATTRIBUTE_SENTRY_SOURCE, source);
+        }
+        // Mark this span as having its name set to prevent future updates
+        addNonEnumerableProperty(rootSpan, '__sentry_navigation_name_set__', true);
+      }
+      // If we already have a name for this span, don't update it
     } else {
-      startBrowserTracingNavigationSpan(client, {
+      const span = startBrowserTracingNavigationSpan(client, {
         name,
         attributes: {
           [SEMANTIC_ATTRIBUTE_SENTRY_SOURCE]: source,
           [SEMANTIC_ATTRIBUTE_SENTRY_OP]: 'navigation',
           [SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN]: `auto.navigation.react.reactrouter_v${version}`,
         },
       });
+
+      // Mark the new span as having its name set
+      if (span) {
+        addNonEnumerableProperty(span, '__sentry_navigation_name_set__', true);
+      }
     }
   }
 }