[scheduler] Fix crash with defer

Doxyfile

@@ -48,7 +48,7 @@ PROJECT_NAME           = ESPHome
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2025.7.0b1
+PROJECT_NUMBER         = 2025.8.0-dev
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

esphome/components/web_server/web_server.h

@@ -78,7 +78,7 @@ enum JsonDetail { DETAIL_ALL, DETAIL_STATE };
   This is because only minimal changes were made to the ESPAsyncWebServer lib_dep, it was undesirable to put deferred
   update logic into that library. We need one deferred queue per connection so instead of one AsyncEventSource with
   multiple clients, we have multiple event sources with one client each. This is slightly awkward which is why it's
-  implemented in a more straightforward way for ESP-IDF. Arudino platform will eventually go away and this workaround
+  implemented in a more straightforward way for ESP-IDF. Arduino platform will eventually go away and this workaround
   can be forgotten.
 */
 #ifdef USE_ARDUINO

esphome/const.py

@@ -4,7 +4,7 @@ from enum import Enum
 
 from esphome.enum import StrEnum
 
-__version__ = "2025.7.0b1"
+__version__ = "2025.8.0-dev"
 
 ALLOWED_NAME_CHARS = "abcdefghijklmnopqrstuvwxyz0123456789-_"
 VALID_SUBSTITUTIONS_CHARACTERS = (

esphome/core/scheduler.cpp

@@ -1,13 +1,13 @@
 #include "scheduler.h"
 
+#include <algorithm>
+#include <cinttypes>
+#include <cstring>
 #include "application.h"
 #include "esphome/core/defines.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
-#include <algorithm>
-#include <cinttypes>
-#include <cstring>
 
 namespace esphome {
 
@@ -86,8 +86,10 @@ void HOT Scheduler::set_timer_common_(Component *component, SchedulerItem::Type
   // ESP8266 and RP2040 are excluded because they don't need thread-safe defer handling
   if (delay == 0 && type == SchedulerItem::TIMEOUT) {
     // Put in defer queue for guaranteed FIFO execution
-    LockGuard guard{this->lock_};
-    this->cancel_item_locked_(component, name_cstr, type);
+    if (is_name_valid_(name_cstr)) {
+      LockGuard guard{this->lock_};
+      this->cancel_item_locked_(component, name_cstr, type);
+    }
     this->defer_queue_.push_back(std::move(item));
     return;
   }