FIX: remap lowpass <= 0 to Nyquist in GDF/EDF reader (#13769)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: HansujaB

doc/changes/dev/13769.bugfix.rst

@@ -0,0 +1 @@
+Fix bug in when reading EDF/GDF files where non-positive lowpass values were not handled correctly, now mapping them to the Nyquist frequency to prevent errors during plotting, by :newcontrib:`Hansuja Budhiraja`.

doc/changes/names.inc

@@ -117,6 +117,7 @@
 .. _Hakimeh Pourakbari: https://github.com/Hpakbari
 .. _Hamid Maymandi: https://github.com/HamidMandi
 .. _Hamza Abdelhedi: https://github.com/BabaSanfour
+.. _Hansuja Budhiraja: https://github.com/HansujaB
 .. _Hari Bharadwaj: https://github.com/haribharadwaj
 .. _Harrison Ritz: https://github.com/harrisonritz
 .. _Hasrat Ali Arzoo: https://github.com/hasrat17

mne/io/edf/edf.py

@@ -975,7 +975,7 @@ def _get_info(
         _set_prefilter(info, edf_info, filt_ch_idxs, "highpass")
         _set_prefilter(info, edf_info, filt_ch_idxs, "lowpass")
 
-    if np.isnan(info["lowpass"]):
+    if np.isnan(info["lowpass"]) or info["lowpass"] <= 0:
         info["lowpass"] = info["sfreq"] / 2.0
 
     if info["highpass"] > info["lowpass"]: