I found a slightly different version on a page which explains that the war song is a parody of the the lyrics Bill posted. It's mixed in with a collection of interesting "trench songs" Here (click).

Never Mind

If the sergeant drinks your rum, never mind
And your face may lose its smile, never mind
He's entitled to a tot but not the bleeding lot
If the sergeant drinks your rum, never mind

When old Jerry shells your trench, never mind
And your face may lose its smile, never mind
Though the sandbags bust and fly you have only once to die,
If old Jerry shells the trench, never mind

If you get stuck on the wire, never mind
And your face may lose its smile, never mind
Though you're stuck there all the day, they count you dead and stop your pay
If you get stuck on the wire, never mind

If the sergeant says you're mad, never mind
P'raps you are a little bit, never mind
Just be calm don't answer back, cause the sergeant stands no slack
So if he says you're mad, well - you are.