Re: CVS bug - invalid change text

[ulrich_straub]

Hi Larry,

First:
--------
Let me thank you for your useful and reasonable advice.

Second:
------------
I was not complaining about wrong text in the sources checked out or in the
repository
(this might be caused indeed by network problems),
but I was complaining about the internal integrity of the CVS repository.
The internal syntax/structure of the repository is maintained by the CVS
server,
and it got corrupted by the CVS server (see below).
This is definitely a flaw in the CVS server.

Third:
--------
I got the repository repaired manually and I found the cause of the
problem.

The problem was caused by following change requests in the repository
(roughly translated)

- delete 43 lines
- insert some "corrupted" text (which did consist of one very long line
instead of 43 individual lines).

I do not know how this text to be inserted got corrupt (could perhaps be a
network problem).
But that is not the problem.
The problem is that CVS seems to enter the change requests into the
repository whithout verifying
that they "make sense".

This change request corrupted the repository, since the line numbers of
earlier versions
became partially invalid.
-->> 43 lines are deleted and only 1 (corrupt) line is inserted.
As a result earlier change requests refering to lines near the end of the
file
suddenly pointed to lines beyond the end of the file
(since the file got 42 lines to short)
These "invalid" line numbers were detected by CVS during a checkout,
and CVS refused the checkout.

Summary: CVS does not verify whether the change request inserted "makes
sense".
Hence "invalid" change requests can corrupt the repository.

Necessary improvements:
This "capabilty" of CVS to corrupt the own repository is a serious flaw and
should be fixed.
Another danger of CVS is that such problems might come into the repository
unnoticed.
I noticed the problem only when I tried to check-out an earlier tag (which
failed).
Additionally CVS should report the line number/section/revision number
where the
invalid syntax is detected, and it should display a short reason message.


Mit freundlichen Gruessen / With kind regards
           Ulrich Straub
CommonStore Development

E-mail:  address@hidden
Tel:  (+49)-7031-16-2884 , Fax -3619
http//:www.ibm.com/software/data/commonstore