Fix: Presence Detector Validation Error with Cached Configuration

[rkntan]

Fix: Presence Detector Validation Error with Cached Configuration

Problem: When the presence detector plugin loads cached configuration with start_m=0.0, end_m=0.31, and automatic_subsweeps=True, the _get_profile_subsweeps function creates a subsweep with num_points=0, which fails validation.

Root Cause: In _get_profile_subsweeps function, when the while loop doesn't execute (when curr_point >= cut_point initially), n_points_in_subsweep remains 0, causing the validation error.

Solution: Add a check to ensure n_points_in_subsweep is always at least 1 before creating the SubsweepConfig.

Changes:

• File: src/acconeer/exptool/a121/algo/presence/_subsweep_utils.py
• Function: _get_profile_subsweeps
• Lines: 119-121 (add check before creating SubsweepConfig)

# Ensure at least 1 point to prevent validation error
if n_points_in_subsweep == 0:
    n_points_in_subsweep = 1

Testing:

• Reproduced the bug with cached configuration and verified the fix prevents the validation error
• Confirmed that purging cache (python -m acconeer.exptool.app --purge-cache) also resolves the issue as a workaround

Impact: High priority - prevents users from using Presence Detector plugin when cached configuration contains problematic parameters.

Workaround: Users can resolve this issue by purging the cache, but this fix prevents it from occurring in the first place.