Fix Phased-Update-Percentage probability mistake

Previously a package with Phased-Update-Percentage: n would be updated
with probability (n + 1)/101 instead of n/100.  For example, a package
with Phased-Update-Percentage: 0 could still be updated even though it
shouldn’t, and a package with Phased-Update-Percentage: 1 would be
installed almost twice as much as it should be.  Correct the erroneous
math.

Note that libstdc++ implements std::uniform_int_distribution in such a
way that for a given seed, changing dist(0, 100) to dist(0, 99) has
the effect of decreasing each sample by 0 or 1; therefore, this patch
will not randomly trigger extra phased updates that had previously
been excluded.

Fixes: c5bc86d45e003905ef411146e66b414d26fb1ff8
Signed-off-by: Anders Kaseorg <andersk@mit.edu>

0 files changed, 0 insertions, 0 deletions