Fix unable to parse nmap output for incomplete XML output

[idkw]

This is a fix for #122

According to golang standard library documentation in https://pkg.go.dev/os/exec#Cmd.StdoutPipe

It is thus incorrect to call Wait before all reads from the pipe have completed

And in

nmap/nmap.go

Line 149 in a750324

err := cmd.Wait()

this is exactly what is done. Wait is called while io.Copy ([1] , [2]) is still performing reads on stdoutDuplicate.

The fix is inspired from a solution to a similar simplified problem

Before calling Wait we wait on a WaitGroup than is done when all reads on stdoutDuplicate have completed.

Finally I've added a test that runs a thousand nmap scans (takes about 5 seconds). The scans are done without a host so it returns almost immediately. You can verify the test fails when commenting out wg.Wait() in nmap.go on line 161. You can verify the test doesn't fail with that wg.Wait().

Feel free to remove the test from the MR if you think it's not worth to keep it once the fix is confirmed to be working.

[Ullaakut]

Thanks, nice catch :))

[idkw]

Thanks @Ullaakut for the quick review, do you think it can be released in a patch version ?