Non-positive hits raises error for corner cases

[dachengx]

Describe the bug
After strax.find_hit_integration_bounds, the "right_integration" might be equal to "left_integration" for hits or lone_hits, so that later will raise error in the functions which require positive length.

There are two cases.

To Reproduce
The first one is for the 519th chunk of 048880

import cutax
st = cutax.xenonnt_offline(xedocs_version='global_v14')
run_id = '048880'
chunk_number = 519
st.make(run_id, 'peaklets', _chunk_number=chunk_number)

shows error

  File "/home/xudc/straxen/straxen/plugins/peaklets/peaklets.py", line 262, in compute
    strax.sum_waveform(
  File "/opt/miniconda3/envs/XENONnT_2024.03.1/lib/python3.9/site-packages/numba/np/arraymath.py", line 572, in impl_max 
    raise ValueError("zero-size array to reduction operation "
ValueError: zero-size array to reduction operation maximum which has no identity

because in https://github.com/AxFoundation/strax/blob/ebcb699fd85edb30b133fcb00e48dafa46faca4c/strax/processing/peak_building.py#L329-L331, if hit["length"] is 0, r_start and r_end are the same.

The second one is for 11th chunk of 044256

import cutax
st = cutax.xenonnt_offline(xedocs_version='global_v14')
run_id = '044256'
chunk_number = 11
st.make(run_id, 'merged_s2s', _chunk_number=chunk_number)

shows error

  File "/opt/XENONnT/anaconda/envs/XENONnT_2024.02.1/lib/python3.9/site-packages/strax/processing/general.py", line 150, in _fully_contained_in_sanity
    raise ValueError(f"{names} should have non-negative length!")
ValueError: things should have non-negative length!

also reported in slack thread. Because in

straxen/straxen/plugins/merged_s2s/merged_s2s.py

Line 140 in 33992c2

lh["length"] = lh["right_integration"] - lh["left_integration"]

, lh["length"] is 0.

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Versions

module	version	path	git
python	3.9.19	/opt/XENONnT/anaconda/envs/XENONnT_2024.03.1/bin/python	None
strax	1.6.2	/home/xudc/strax/strax	branch:master
straxen	2.2.1	/home/xudc/straxen/straxen	branch:master
cutax	1.17.1	/home/xudc/cutax/cutax	branch:master

[yuema137]

Seems to be a very low-level bug. Let me try to look into it