Issue 21469: Mitigate risk of false positives with robotparser.
* Repair the broken link to norobots-rfc.txt.
* HTTP response codes >= 500 treated as a failed read rather than as a not
found. Not found means that we can assume the entire site is allowed. A 5xx
server error tells us nothing.
* A successful read() or parse() updates the mtime (which is defined to be "the
time the robots.txt file was last fetched").
* The can_fetch() method returns False unless we've had a read() with a 2xx or
4xx response. This avoids false positives in the case where a user calls
can_fetch() before calling read().
* I don't see any easy way to test this patch without hitting internet
resources that might change or without use of mock objects that wouldn't
provide must reassurance.
2 files changed