cgo: Dormqr comment not in sync with reality

[vladimir-ch]

The comment says:

// ... lwork == -1 will not run Dormqr but will instead write the minimum
// work necessary to work[0]. If len(work) < lwork, Dormqr will panic.

The code does:

        if lwork == -1 {
                 if left {
                         work[0] = float64(m)
                         return
                 }
                 work[0] = float64(n)
                 return
         }

         if left {
                 if lwork < n {
                         panic(badWork)
                 }
         } else {
                 if lwork < m {
                         panic(badWork)
                 }
         }

That is,

1. Values put into work[0] and checked values of lwork seem to be swapped.
2. len(work) < lwork is not checked.

[kortschak]

1. I can't see where this is happening. The code I have in front of me assigns a f(n) to work[0] when left and a f(m) to work[0] otherwise.
2. This happens in subordinate calls AFAICS, but it might be worth hoisting it higher up the call chain.

[vladimir-ch]

I'm referring to cgo.

[kortschak]

Sorry.

[vladimir-ch]

This happens in subordinate calls AFAICS, but it might be worth hoisting it higher up the call chain.

I think it would be worth it.

[kortschak]

I'll send a PR in a sec that addresses both of these things.