Here are some more instances of the mergeinfo count bug:
% f() { /root/bin/dump-noderev.pl /x1/svn/asf / $1 | grep -a minfo-cnt }
REVISION minfo-cnt of /'s noderev
======== ========================
r891679 minfo-cnt: 34417890202
r905000 minfo-cnt: 34417892519
r907500 minfo-cnt: 34417892785
r908100 minfo-cnt: 34417892803
r908450 minfo-cnt: 34417892746
r908575 minfo-cnt: 34417893806
r908625 minfo-cnt: 34417893808
r908650 minfo-cnt: 34417893809
r908651 minfo-cnt: 34417893809
r908652 minfo-cnt: 34417893809
r908653 minfo-cnt: 688257838809
r908654 minfo-cnt: 103243186689
r908655 minfo-cnt: 137656732313
r908656 minfo-cnt: 172067779391
r908657 minfo-cnt: 172069356354
r908658 minfo-cnt: 172069356354
r908659 minfo-cnt: 172069356354
r908660 minfo-cnt: 172069356354
r908675 minfo-cnt: 172069356354
r908800 minfo-cnt: 172069356351
r910000 minfo-cnt: 172069356907
r908653 adds 996 files, removes 2 and modifies 2.
r908654 modifies 5 files.
r908655 adds 3 files.
Going back to the original instance --- Julian's r891679 --- I see that
r891676 modifies 149 files.
---
Analysis: the minfo-cnt bug has definitely been triggered more than
once. It might be connected to commits that touch many files
(see [1]), but that is not yet confirmed.
[1] http://subversion.tigris.org/issues/show_bug.cgi?id=3506
https://issues.apache.org/jira/browse/INFRA-2261
(two links, same issue)