CVS thinks a file is up-to-date even after it's modified

[Yu Fang]

Hi,

I wrote a perl script that does following:

* remove a file from work area that's under CVS control
* use 'cvs -Q update <file>' to bring latest version of file
  back into work area
* open the file and modify it, then close it
* then use 'cvs commit <file>' to commit the changes

What I found is that sometimes CVS will refuse to do the
commit because it thinks the file is still up-to-date even
though it's been modified.

I wonder how CVS determines whether a file is up-to-date.
I guess it uses some sort of time stamp and the change may
have happened too quickly that the time stamp didn't get
changed.

Please help.

Yu Fang