Is 1 zero or nonzero?



I was looking at the (reported) bug 

  (%i1) polarform((a+1)/2 - a/2 - 1/2);
  atan2: atan2(0,0) is undefined.

Stavros suggested a call to csign in absarg--I tried doing that:

  (%i10) polarform(%i * inf);

  0> Calling (ABSARG ((MTIMES SIMP) $%I $INF)) 
  Is  1  zero or nonzero?

The test  carg(%i*inf) is in rtest_carg. 

Does anybody know something about this silly askskign? Does  some special variable  need to be set? 

--Barton