Erroneous (?) geometry error

[depmco]

I seem to have found a bug; whether it's in nec2++ or my head is still a question. I'm running the following version:

nec2++ 1.7.4 [2025-07-09] compiler: 13.3.0

on Linux Mint 22.1 Xia

Running the following short model file:

CM NEC2++ Test structure
CE
GW 1 11 0.0     0.0      1.0204     0.0     0.0        1.5306        0.002
GW 2 11 0.0     0.0      1.5306     0.36077 0.36077    1.5306        0.002
GW 3 11 0.36077 0.36077  1.5306     0.36077 0.36077    1.5506        0.002
GW 10 11 0.0     0.0      1.0204     0.5102  0.0        1.0204        0.002
GE 0
EX 0 1 1 00 1.0 0.0
GN 1
FR 0 40 0 0 146.0 0.05
RP  0 181   360 0010       0.0       0.0       1.0       1.0
XQ 3
EN

produces the error on the console:

NEC++ Runtime Error: 
GEOMETRY DATA ERROR -- FIRST SEGMENT MIDPOINT OF WIRE #3 (TAG ID #3) INTERSECTS WIRE #2 (TAG ID #2)

and the file output for the run contains:

                                __________________________________________
                               |                                          |
                               | NUMERICAL ELECTROMAGNETICS CODE (nec2++) |
                               | Implemented in 'C++' in Double Precision |
                               |        Version 1.7.4 [2025-07-09]        |
                               |__________________________________________|



                               ---------------- COMMENTS ----------------
                                NEC2++ Test structure
                               



                                -------- STRUCTURE SPECIFICATION --------
                                COORDINATES MUST BE INPUT IN
                                METERS OR BE SCALED TO METERS
                                BEFORE STRUCTURE INPUT IS ENDED
  WIRE                                                                                 SEG FIRST  LAST  TAG
   No:        X1         Y1         Z1         X2         Y2         Z2       RADIUS   No:   SEG   SEG  No:

     1      0.0000     0.0000     1.0204     0.0000     0.0000     1.5306     0.0020    11     1    11    1
     2      0.0000     0.0000     1.5306     0.3608     0.3608     1.5306     0.0020    11    12    22    2
     3      0.3608     0.3608     1.5306     0.3608     0.3608     1.5506     0.0020    11    23    33    3                               NEC++ Runtime Error: 
                               GEOMETRY DATA ERROR -- FIRST SEGMENT MIDPOINT OF WIRE #3 (TAG ID #3) INTERSECTS WIRE #2 (TAG ID #2)

The error seems erroneous; xnecview shows no intersection and nec2c completes without error on the same file.