Fix: Prevent SetDefaultEventParameters from clearing params with all-…

analytics/src/analytics_android.cc

@@ -627,6 +627,7 @@ void SetDefaultEventParameters(
     return;
   }
 
+  bool any_parameter_added = false;
   for (const auto& pair : default_parameters) {
     const Variant& value = pair.second;
     const char* key_cstr = pair.first.c_str();
@@ -648,14 +649,18 @@ void SetDefaultEventParameters(
         LogError(
             "SetDefaultEventParameters: Failed to put null string for key: %s",
             key_cstr);
+      } else {
+        any_parameter_added = true;
       }
       env->DeleteLocalRef(key_jstring);
     } else if (value.is_string() || value.is_int64() || value.is_double() ||
                value.is_bool()) {
       // AddVariantToBundle handles these types and their JNI conversions.
       // It also logs if an individual AddToBundle within it fails or if a type
       // is unsupported by it.
-      if (!AddVariantToBundle(env, bundle, key_cstr, value)) {
+      if (AddVariantToBundle(env, bundle, key_cstr, value)) {
+        any_parameter_added = true;
+      } else {
         // This specific log gives context that the failure happened during
         // SetDefaultEventParameters for a type that was expected to be
         // supported by AddVariantToBundle.
@@ -681,6 +686,14 @@ void SetDefaultEventParameters(
     }
   }
 
+  if (!any_parameter_added) {
+    LogDebug(
+        "SetDefaultEventParameters: No valid parameters were processed, "
+        "skipping native call to avoid clearing existing parameters.");
+    env->DeleteLocalRef(bundle);
+    return;
+  }
+
   env->CallVoidMethod(
       g_analytics_class_instance,
       analytics::GetMethodId(analytics::kSetDefaultEventParameters), bundle);

analytics/src/analytics_ios.mm

@@ -403,6 +403,15 @@ void SetDefaultEventParameters(const std::map<std::string, Variant>& default_par
                pair.first.c_str(), Variant::TypeName(value.type()));
     }
   }
+  // If ns_default_parameters is empty at this point, it means all input
+  // parameters were invalid or the input map itself was empty.
+  // In this case, we should not call the native SDK, as passing an empty
+  // NSDictionary might clear existing parameters, which is not the intent
+  // if all inputs were simply invalid.
+  if ([ns_default_parameters count] == 0) {
+    LogDebug("SetDefaultEventParameters: No valid parameters to set, skipping native call.");
+    return;
+  }
   [FIRAnalytics setDefaultEventParameters:ns_default_parameters];
 }