Good morning Paul,
Paul Burba wrote on Mon, Apr 25, 2011 at 14:55:02 -0400:
> On Mon, Apr 25, 2011 at 11:56 AM, Paul Burba <ptburba_at_gmail.com> wrote:
> > On Sat, Apr 23, 2011 at 5:21 AM, Daniel Shahaf <d.s_at_daniel.shahaf.name> wrote:
> >> On Sat, 23 Apr 2011 07:15 +1000, "Daniel Becroft" <djcbecroft_at_gmail.com> wrote:
> >> [[[
> >> % rm -rf wc1 r1
> >> % $svnadmin create r1
> >> % $svn co file://$PWD/r1 wc1
> >> Checked out revision 0.
> >> % cd wc1
> >> % $svn cp . trunk
> >> svn: E200007: Cannot copy path '/tmp/svn/wc1' into its own child '/tmp/svn/wc1/trunk'
> >> % $svn cp ^/ ^/trunk -mm
> >
> > Hi Daniel,
> >
> > Should we even allow a copy of r0? What exactly does it mean and how
> > is it useful?
> >
> > The assert you see here happens because mergeinfo has no concept of r0
> > as a valid change. When we try this switch without using
> > --ignore-ancestry, switch.c:switch_internal() calls
> > svn_client__get_youngest_common_ancestor looking for common ancestor
> > of ^/trunk_at_1 and ^/@0. svn_client__get_youngest_common_ancestor()
> > uses svn_client__get_history_as_mergeinfo() to convert ^/trunk_at_1 and
> > /^@0 to svn_mergeinfo_t.
> >
> > Unfortunately svn_client__get_history_as_mergeinfo() does this
> > conversion by using svn_mergeinfo__mergeinfo_from_segments() to covert
> > svn_location_segment_t's into mergeinfo.
> > svn_location_segment_t.range_start can be the same as
> > svn_location_segment_t.range_end, but when
> > svn_mergeinfo__mergeinfo_from_segments converts these to
> > svn_merge_range_t, it enforces the rule that svn_merge_range_t.start <
> > svn_merge_range_t.end (see
> > http://svn.apache.org/viewvc?view=revision&revision=924201).
> >
> > So we end up with a bogus rangelist that later trips the assert when
> > svn_client__get_youngest_common_ancestor() sends it to the
> > svn_rangelist_intersect API.
> >
> > Unsure how to address this. We could tweak
> > svn_client__get_youngest_common_ancestor() to handle this edge case,
> > but I wonder if preventing copies of r0 in the first place is
> > something to consider too.
>
> We allowed this in 1.6, so I made a few changes in r1096561 and
> r1906562 to continue supporting it.
>
Thanks for the detailed explanation.
I agree that copying r0 should be allowed.
> Paul
Daniel
Received on 2011-04-25 21:19:50 CEST