[Bug-wget] Sometimes servers return false "HTTP 1.1 416" response when "--continue" and "--timestamping"

[Alex]

Greetings.

Reported by kenny5705 - "Some files from "downloads.microsoft.com" with
"-cN" key combination don't resume downloads with 416 error".

If send HEAD request with correct "Range : bytes" headers mostly servers  
answers
"HTTP 1.1 200", but sometime they can answer "HTTP 1.1 416" (and as result,
resuming download interrupts with "The file is already fully retrieved;
nothing to do.").

Also check this with Curl. Logs in zip in attachment.

As far as I can see/understood, "Range" in HEAD request isn't mandatory.
It is safe to remove it (and send only in GET requests)? Possible patch in  
zip.
Check - it resumes downloads as should.

PS. I don't understood... Two days ago this is happens much more  
frequently... But i'm was unawared and didn't saves all logs. Now it  
appeared only if exist large (several hours) time interval before last  
tries...

Best regars, Alex

416_error_log.zip
Description: Zip archive