Fix #1001

[ivandi69]

This PR addresses #1001.
Looks like in the case of crash on startup ngspice doesn't output anything to stdout or stderr:

But we can handle the crash correctly:

[ra3xdh]

Still show an empty log for me using the test project (IGBT) from the first post in this thread. The log should be the following:

Circuit: * qucs 24.4.0  /home/vvk/.qucs/igbt_prj/igp20n60h3_dc_sweep.sch

Netlist line no. 5:
Undefined parameter [tj]
Netlist line no. 5:
 Formula() error.
      |tj=tj;| : |tj|=|tj|
Netlist line no. 9:
Undefined parameter [tj]
Netlist line no. 9:
 Formula() error.
      |n8ge3=0.013854554023489; n8ff6=1.57882194219674; n8702=3.46930288988777e-11; n86w9=8.41433062117716e-08; n84aq=1.32519041443202e-08; n7wd0=1.33871871875805e-08; n7v3x=9.92760529520462e-08; n7plu=1.50428905421895e-08; n7823=18.9093015526887; n77o2=6.45408315816135; n76ve=0; n76ll=0; n6zjd=0; n6yi8=0; n6ty8=0.00632004656777681; n6so3=2.29893281050078; n6lvg=-0.00133204969289205; n6i8c=-0.852047059737599; n6gn0=0.737142387800282; n6fw5=52.7037916495759; n6e08=-3.94369540325447e-06; n6cmj=0.0223970224737104; n6703=-7.77904953072956e-07; n65sh=-8.12563094647835e-05; n612n=7.97661835108196e-07; n60nx=-1.57641345523649e-05; n5yr0=9.47679870056731e-05; n5t5m=0.0368287907165867; n5s9x=9.65764610194974; n5s7h=0.000325950898955632; n5k9k=131.741872758703; tj=tj; n5e0u=n5e0u; n5ec8=n5ec8; kp=kp; n5m7t=n5m7t; n5q0a=n5q0a; is=is; n7l5l=n7l5l; n7ufh=n7ufh; n81cq=n81cq; n88ys=n88ys; n89dm=n89dm; n8dab=n8dab; n5t3b=n5t3b; n5zfd=n5zfd; n61an=n61an; n69y7=n69y7; n6edj=n6edj; n6gy2=n6gy2; n6pyf=n6pyf; n6uwq=n6uwq; n718f=n718f; n7w4m=n7w4m; n7yht=n7yht; n7zfx=n7zfx; n82h0=n82h0; n84cu=n84cu; n84k3=n84k3; n85kn=n85kn; n5kzl=n5kzl; n87xb=n87xb; n7tca=n7tca; n7tkt=n7tkt; n5lrx=n5lrx; n5lzv=n5lzv; n69hc=n69hc; n79xk=n79xk; n7b2g=n7b2g; n7b5h=n7b5h; n7ct5=n7ct5; n7drb=n7drb; n7gyu=n7gyu;| : |tj|=|tj|
Numparam expansion errors: Run Spice anyway? y/n ?
y
Error: no such function 'if' at line 99
from file
  "/home/vvk/.qucs/IGBT_prj/IGP20N60H3.cir

ERROR: fatal error in ngspice, exit(1)

I suspect that Ngspice requires a -b (batch mode) parameter. Otherwise it waits for the user input and cannot generate the output. It cannot recognize if it runs as the child process or with output redirection.

[ra3xdh]

I have tried the -b and it has no effect in child process mode. Probably Ngspice has problems when output redirection is used. Makes sense to provide a minimal example and report to Ngspice team.

[ivandi69]

Ngspice crashes when compatibility mode is set. It doesn't crash in normal mode. It outputs the error log you see.

This PR fixes the misleading "Simulation successful" message displayed by Qucs-s after a simulator crash.
The ngspice crash should be reported to developers.

[ivandi69]

Here is an example in terminal:

[ra3xdh]

Thanks! Merged. The crash should be reported to Ngspice team.