no content change detected when a file is replaced by a different one created at the same time or earlier

Hi,

I have first reported this issue in Jetty's bugzilla. There, Jan Bartel sent me here, helping me realize that it was part of a bigger picture that had been heavily discussed for Tomcat (see [https://issues.apache.org/bugzilla/show_bug.cgi?id=33453](https://issues.apache.org/bugzilla/show_bug.cgi?id=33453)).

The problem I'm reporting occurs even in development mode (no other associated param set), where each JSP page change should be checked and detected for each access.

When a JSP file that has been accessed (compiled) is replaced (by command mv or rsync, for example) by a different file (content or size) that happens to have been created at the same time or earlier, changes remain undetected and the initial (obsolete) content is still served.
It took us hours to figure out why some pages where not updated.

Sidenote: we would have expected a real development mode where changes would be detected with "perfect" reliability (checksum) for each access whatever the nature of the change is, and a more production-oriented mode where they would be detected with best effort (if timestamp or size is different) for each access. And no mode we are aware of seems to correspond to these needs, that we would have thought quite common.

Thanks