patchgit-cvsimport: strip question-mark characters in tags

Question mark character appears to be valid in a CVS tag, but not a git one. Remove it. Leave open the possibility that there may be more such characters; and comment (FIXME) that we may want to replace those instead of removing them.

Also: if git tag command fails, do not include $! in our
error message: it is not useful after system(), and will
only serve as a red herring.
---
 git-cvsimport.perl |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

Ed Santiago <santiago@redhat.com> writes:

I agree that people may want to optionally replace them to avoid mapping two originally different tags into the same one.

Does your regexp chain check other invalid refname sequences, such as ".name", "na..me", etc.?

Sign-off?

On Wed, Apr 14, 2010 at 07:29:03AM -0700, Junio C Hamano wrote:

I considered that but decided that it was beyond the scope of what I wanted to tackle. My intent was to suggest an incremental fix, not a revolutionary one. I also wished to remove a misleading diagnostic[1] and provide a way for others to do the same as needed.

 [1] The error I saw was "Cannot create tag mumblefoo{?dist}: Illegal seek",
     where "Illegal seek" is due to an uninitialized/invalid $!

A proper solution would, I believe, be uncomfortably complex. Some of the approaches I considered are:

  * command-line option '--tag-replace <from-char>=<to>', eg '?=-'
  * replacing a (hardcoded) list of chars with %xx hex codes
  * option a la -A, with a file listing <oldtag>=<newtag>
  * like above, but the file lists perl expressions such as s/\?/./g

I used git-cvsimport because I've used tailor[2] before and dreaded the thought of running it again. I love how easy git-cvsimport was to use! I see it as a great tool for quick jobs, for proof-of-concept situations: it has a low cost of entry, works well with a remote CVS repo, and was easy to debug. But if it were to become as configurable -- and as complex -- as tailor, I think it might lose much of its value.

 [2] http://wiki.darcs.net/RelatedSoftware/Tailor

Eek, no. Again, this was a purely incremental fix, an addition to an existing (simple) check. Duplicating the functionality of git-check-ref-format would be a terrible idea. But if there's already a perlified library for this, or a portable hook into git itself (I haven't looked), it might be wise to have git-cvsimport use that to check/convert tags. At the very least it would give a much better error to the end user.

My apologies.  I'm new to this.

How would you like me to proceed? I'm reluctant to code a full general solution to the tag-validity problem, but am happy to rework my changes into something better.

Thanks for your feedback, Ed

Ed Santiago <santiago@redhat.com> writes:

Oh, one step at a time is perfectly fine.

Ed Santiago <santiago@redhat.com> writes:

According to the CVS docs only letters, digits, '-' and '_' are valid for tag names.

Andreas.

On Wed, Apr 14, 2010 at 10:44:45PM +0200, Andreas Schwab wrote:

Poor choice of words on my part. What I *should* have said is something like:

   Although question marks and curly braces are not among the
   set of characters which CVS considers to be valid for a tag,
   real-world situations have been encontered in which a CVS
   comma-v file has a tag including all those characters.  This
   patch makes git-cvsimport accept and forgive that reality.

How that tag got created, I really don't know. I can imagine three ways it could've happened (rcs commands; broken/old version of CVS; custom tool for mucking with comma-v files). My goal was to recognize that this sort of thing happens, and to make it easier for the next person to find & fix this in the script. With that goal in mind, removing $! and adding the comment is the only important part of my patch. The question mark itself is not likely to be useful except in very rare and weird cases.

Ed

On Wednesday 14 April 2010, Ed Santiago wrote:

Indeed. I have even seen CVS tag names containing carriage returns (aka. CR, \r) in the wild...

...Johan