[scheduler] Fix cancellation of timers with empty string names (#9641)

esphome/core/component.cpp

@@ -252,10 +252,10 @@ void Component::defer(const char *name, std::function<void()> &&f) {  // NOLINT
   App.scheduler.set_timeout(this, name, 0, std::move(f));
 }
 void Component::set_timeout(uint32_t timeout, std::function<void()> &&f) {  // NOLINT
-  App.scheduler.set_timeout(this, "", timeout, std::move(f));
+  App.scheduler.set_timeout(this, static_cast<const char *>(nullptr), timeout, std::move(f));
 }
 void Component::set_interval(uint32_t interval, std::function<void()> &&f) {  // NOLINT
-  App.scheduler.set_interval(this, "", interval, std::move(f));
+  App.scheduler.set_interval(this, static_cast<const char *>(nullptr), interval, std::move(f));
 }
 void Component::set_retry(uint32_t initial_wait_time, uint8_t max_attempts, std::function<RetryResult(uint8_t)> &&f,
                           float backoff_increase_factor) {  // NOLINT

esphome/core/scheduler.cpp

@@ -446,7 +446,7 @@ bool HOT Scheduler::cancel_item_(Component *component, bool is_static_string, co
 // Helper to cancel items by name - must be called with lock held
 bool HOT Scheduler::cancel_item_locked_(Component *component, const char *name_cstr, SchedulerItem::Type type) {
   // Early return if name is invalid - no items to cancel
-  if (name_cstr == nullptr || name_cstr[0] == '\0') {
+  if (name_cstr == nullptr) {
     return false;
   }
 

esphome/core/scheduler.h

@@ -114,16 +114,17 @@ class Scheduler {
         name_is_dynamic = false;
       }
 
-      if (!name || !name[0]) {
+      if (!name) {
+        // nullptr case - no name provided
         name_.static_name = nullptr;
       } else if (make_copy) {
-        // Make a copy for dynamic strings
+        // Make a copy for dynamic strings (including empty strings)
         size_t len = strlen(name);
         name_.dynamic_name = new char[len + 1];
         memcpy(name_.dynamic_name, name, len + 1);
         name_is_dynamic = true;
       } else {
-        // Use static string directly
+        // Use static string directly (including empty strings)
         name_.static_name = name;
       }
     }

tests/integration/fixtures/scheduler_string_test.yaml

@@ -4,9 +4,7 @@ esphome:
     priority: -100
     then:
       - logger.log: "Starting scheduler string tests"
-  platformio_options:
-    build_flags:
-      - "-DESPHOME_DEBUG_SCHEDULER"  # Enable scheduler debug logging
+  debug_scheduler: true  # Enable scheduler debug logging
 
 host:
 api:
@@ -32,6 +30,12 @@ globals:
   - id: results_reported
     type: bool
     initial_value: 'false'
+  - id: edge_tests_done
+    type: bool
+    initial_value: 'false'
+  - id: empty_cancel_failed
+    type: bool
+    initial_value: 'false'
 
 script:
   - id: test_static_strings
@@ -147,12 +151,106 @@ script:
           static TestDynamicDeferComponent test_dynamic_defer_component;
           test_dynamic_defer_component.test_dynamic_defer();
 
+  - id: test_cancellation_edge_cases
+    then:
+      - logger.log: "Testing cancellation edge cases"
+      - lambda: |-
+          auto *component1 = id(test_sensor1);
+          // Use a different component for empty string tests to avoid interference
+          auto *component2 = id(test_sensor2);
+
+          // Test 12: Cancel with empty string - regression test for issue #9599
+          // First create a timeout with empty name on component2 to avoid interference
+          App.scheduler.set_timeout(component2, "", 500, []() {
+            ESP_LOGE("test", "ERROR: Empty name timeout fired - it should have been cancelled!");
+            id(empty_cancel_failed) = true;
+          });
+
+          // Now cancel it - this should work after our fix
+          bool cancelled_empty = App.scheduler.cancel_timeout(component2, "");
+          ESP_LOGI("test", "Cancel empty string result: %s (should be true)", cancelled_empty ? "true" : "false");
+          if (!cancelled_empty) {
+            ESP_LOGE("test", "ERROR: Failed to cancel empty string timeout!");
+            id(empty_cancel_failed) = true;
+          }
+
+          // Test 13: Cancel non-existent timeout
+          bool cancelled_nonexistent = App.scheduler.cancel_timeout(component1, "does_not_exist");
+          ESP_LOGI("test", "Cancel non-existent timeout result: %s",
+                   cancelled_nonexistent ? "true (unexpected!)" : "false (expected)");
+
+          // Test 14: Multiple timeouts with same name - only last should execute
+          for (int i = 0; i < 5; i++) {
+            App.scheduler.set_timeout(component1, "duplicate_timeout", 200 + i*10, [i]() {
+              ESP_LOGI("test", "Duplicate timeout %d fired", i);
+              id(timeout_counter) += 1;
+            });
+          }
+          ESP_LOGI("test", "Created 5 timeouts with same name 'duplicate_timeout'");
+
+          // Test 15: Multiple intervals with same name - only last should run
+          for (int i = 0; i < 3; i++) {
+            App.scheduler.set_interval(component1, "duplicate_interval", 300, [i]() {
+              ESP_LOGI("test", "Duplicate interval %d fired", i);
+              id(interval_counter) += 10; // Large increment to detect multiple
+              // Cancel after first execution
+              App.scheduler.cancel_interval(id(test_sensor1), "duplicate_interval");
+            });
+          }
+          ESP_LOGI("test", "Created 3 intervals with same name 'duplicate_interval'");
+
+          // Test 16: Cancel with nullptr protection (via empty const char*)
+          const char* null_name = "";
+          App.scheduler.set_timeout(component2, null_name, 600, []() {
+            ESP_LOGE("test", "ERROR: Const char* empty timeout fired - should have been cancelled!");
+            id(empty_cancel_failed) = true;
+          });
+          bool cancelled_const_empty = App.scheduler.cancel_timeout(component2, null_name);
+          ESP_LOGI("test", "Cancel const char* empty result: %s (should be true)",
+                   cancelled_const_empty ? "true" : "false");
+          if (!cancelled_const_empty) {
+            ESP_LOGE("test", "ERROR: Failed to cancel const char* empty timeout!");
+            id(empty_cancel_failed) = true;
+          }
+
+          // Test 17: Rapid create/cancel/create with same name
+          App.scheduler.set_timeout(component1, "rapid_test", 5000, []() {
+            ESP_LOGI("test", "First rapid timeout - should not fire");
+            id(timeout_counter) += 100;
+          });
+          App.scheduler.cancel_timeout(component1, "rapid_test");
+          App.scheduler.set_timeout(component1, "rapid_test", 250, []() {
+            ESP_LOGI("test", "Second rapid timeout - should fire");
+            id(timeout_counter) += 1;
+          });
+
+          // Test 18: Cancel all with a specific name (multiple instances)
+          // Create multiple with same name
+          App.scheduler.set_timeout(component1, "multi_cancel", 300, []() {
+            ESP_LOGI("test", "Multi-cancel timeout 1");
+          });
+          App.scheduler.set_timeout(component1, "multi_cancel", 350, []() {
+            ESP_LOGI("test", "Multi-cancel timeout 2");
+          });
+          App.scheduler.set_timeout(component1, "multi_cancel", 400, []() {
+            ESP_LOGI("test", "Multi-cancel timeout 3 - only this should fire");
+            id(timeout_counter) += 1;
+          });
+          // Note: Each set_timeout with same name cancels the previous one automatically
+
   - id: report_results
     then:
       - lambda: |-
           ESP_LOGI("test", "Final results - Timeouts: %d, Intervals: %d",
                    id(timeout_counter), id(interval_counter));
 
+          // Check if empty string cancellation test passed
+          if (id(empty_cancel_failed)) {
+            ESP_LOGE("test", "ERROR: Empty string cancellation test FAILED!");
+          } else {
+            ESP_LOGI("test", "Empty string cancellation test PASSED");
+          }
+
 sensor:
   - platform: template
     name: Test Sensor 1
@@ -189,12 +287,23 @@ interval:
             - delay: 0.2s
             - script.execute: test_dynamic_strings
 
+  # Run cancellation edge case tests after dynamic tests
+  - interval: 0.2s
+    then:
+      - if:
+          condition:
+            lambda: 'return id(dynamic_tests_done) && !id(edge_tests_done);'
+          then:
+            - lambda: 'id(edge_tests_done) = true;'
+            - delay: 0.5s
+            - script.execute: test_cancellation_edge_cases
+
   # Report results after all tests
   - interval: 0.2s
     then:
       - if:
           condition:
-            lambda: 'return id(dynamic_tests_done) && !id(results_reported);'
+            lambda: 'return id(edge_tests_done) && !id(results_reported);'
           then:
             - lambda: 'id(results_reported) = true;'
             - delay: 1s

tests/integration/test_scheduler_heap_stress.py

@@ -103,13 +103,14 @@ async def test_scheduler_heap_stress(
 
         # Wait for all callbacks to execute (should be quick, but give more time for scheduling)
         try:
-            await asyncio.wait_for(test_complete_future, timeout=60.0)
+            await asyncio.wait_for(test_complete_future, timeout=10.0)
         except asyncio.TimeoutError:
             # Report how many we got
+            missing_ids = sorted(set(range(1000)) - executed_callbacks)
             pytest.fail(
                 f"Stress test timed out. Only {len(executed_callbacks)} of "
                 f"1000 callbacks executed. Missing IDs: "
-                f"{sorted(set(range(1000)) - executed_callbacks)[:10]}..."
+                f"{missing_ids[:20]}... (total missing: {len(missing_ids)})"
             )
 
         # Verify all callbacks executed