Fix null dereference in scheduler tick processing - #4571
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In trainprogram::scheduler(), bluetoothManager->device()->odometer() is called unconditionally at line 869. The null guard at line 626 does NOT protect this call — it enters an if-block that handles the 'not ready' case (Zwift API, OCR, etc.) but then falls through to line 869 regardless. If the device disconnects or is null at this point, the code crashes with a null pointer dereference. Fix: Add explicit null guard for both bluetoothManager and device() before the odometer() call. This ensures the scheduler exits safely if the device is unavailable.
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Fix null dereference in scheduler path
Problem
In
trainprogram.cpp:869,odometer()is called unconditionally:This occurs before the null-guard at line 626, creating a TOCTOU race condition:
If the device disconnects between these operations, the code crashes.
Root Cause
Method
timeRateFromGPX()callsbluetoothManager->device()->odometer()without checking if device is null (TOCTOU race).Solution
Add a null guard before the odometer() call to prevent crash under race conditions.
Changes
trainprogram.cpp:869before device access