Help needed with suspicious code in Sparse.cc

[John W. Eaton]

Clang is generating the following warning:

  Sparse.cc:136:18: warning: explicitly assigning value of variable of 
type 'octave_idx_type' (aka 'int') to itself [-Wself-assign]
    for (i = i; i < u; i++)
         ~ ^ ~

The same thing appears on line 946 in that file.

It looks to me as if the code is correct, but the warning could be 
avoided if the loop were written as

  for (; i < u; i++)

Could someone who understands the sparse matrix code comment?

Thanks,

jwe