Property change notifications for "svn:mergeinfo"

On Wed, 04 Apr 2007, Kamesh Jayachandran wrote:

> Paul Burba wrote:
...
> >If so this is somewhat of a separate issue. Currently we do treat the
> >svn:mergeinfo prop as special and don't notify regarding changes to it
> >(hmmm, not sure if this always true but I think it is ATM). I'm not
> >sure if this was by design, I see nothing in the specs that indicates it
> >was, perhaps Dan or Kamesh can speak to this? Regardless I think the
> >current behavior is correct, svn:mergeinfo changes show up in status
> >(they are after all properties), but I wouldn't want to see them in the
> >output of svn merge since I see them more as meta-(meta?)-data on the
> >merge rather than part of it.
>
> Yes since r19954(erstwhile merge-tracking branch) this suppression seems
> to be in place. Though I could not see the log message stating the same.

This was an unintended side-effect of r19954. The deal with property
"merging" is that we don't actually do it using a diff or diff3
algorithm. subversion/libsvn_wc:svn_wc__merge_props() is a big nasty
routine that handles all the possible permutations of "merging"
explicitly (most "merges" result in conflicts, as heavy users of
svnmerge.py are probably well aware from the joyful dir_conflicts.prej
files which are often the result of a merge). I personally find this
somewhat strange, since we have sufficient information to use the
diff3 algorithm. I'm assuming it's simply that no one has found the
time to implement this, given that a typical case probably involves
single-line property values where diff3 is of little assistance.

Handling of the "svn:mergeinfo" property was hacked into
svn_wc__merge_props() in all the places that previously resulted in
property conflicts, adding intelligent merging of the merge info
itself. However, we aren't currently setting the property state
output variable to the appropriate value for each merge.

Should we announce property changes to the "svn:mergeinfo" property?
I think so.