This is a possible fix for the bug reported in [1].

The first commit fixes the runtime failure due to the assert() statement.

The second commit replaces the assert() statements with a macro that
triggers a BUG().

The third commit adds another test that shows a more complicated example and
how the new code in v2.25.0-rc1 has a behavior change that is not
necessarily wanted.

Thanks, -Stolee

[1]
https://lore.kernel.org/git/CAHt=fUXTHc4JPsapvHKnw5vHhp2cBOYRNfdaSDWBUnKt8fWfeA@mail.gmail.com/

Derrick Stolee (3):
  graph: fix case that hit assert()
  graph: replace assert() with graph_assert() macro
  t4215: add bigger graph collapse test

 graph.c                      |  39 +++++++------
 t/t4215-log-skewed-merges.sh | 105 +++++++++++++++++++++++++++++++++++
 2 files changed, 126 insertions(+), 18 deletions(-)

base-commit: 8679ef24ed64018bb62170c43ce73e0261c0600a

Submitted-As: https://lore.kernel.org/git/pull.517.git.1578408947.gitgitgadget@gmail.com