Timeline

The cycle panic was in the indent computation, and rewriting it made the panic go away without my being able to explain the arithmetic -- 32*2 into a 64-byte buffer should not overflow. This asserts the bound directly, so the renderer's assumption is checked rather than believed. closed check-in: 5a35874240 user: dmestas tags: strata

Three holes found by walking the scenario space rather than the happy path.

A retarget could make a cycle. Every segment in one then refuses forever, each waiting on the next, and 'ls' panicked outright computing an indent for a chain with no bottom. Cycles are now refused, direct and indirect.

A retarget accepted a branch name that does not resolve, minting a permanent record aimed at nothing -- the check 'open' has always made before minting one.

A branch already contained in its target reported 'did not merge cleanly; resolve and commit'. There was nothing to resolve: 'merge' had said 'already up to date'. The record could then only be closed by rejecting it, recording the opposite of what happened. It now settles as accepted with no merge, which is what is true. Reachable from a stack by landing the top segment first -- it carries the ones below it in. check-in: b450374bce user: dmestas tags: strata

The ordering guard only looked for an OPEN base, so a rejected one slipped through and the accept SUCCEEDED -- 'accepted seg2 -> seg1', filing the work on a branch nobody would land. Nothing failed and nothing warned; the merge is fine, which is why only a rule catches it. Same hole for a base that already landed, reachable when the auto-retarget after that accept did not run.

All three cases now refuse and name the retarget that fixes them.

Documented the half of this that surprises: rejecting a landing rejects the proposal, not the code beneath a segment stacked on it. That branch descends from the rejected one and still carries its check-ins, so landing it on trunk lands them too. check-in: f91105346b user: dmestas tags: strata

The propagating form marked every segment ABOVE a landed one closed too: in a stack those check-ins descend from the landed tip, so propagation followed the DAG straight into work that was still open. The landing records stayed open and correct; only 'branch' and 'leaves' lied, which is exactly where you look for what still needs doing.

Fossil's own propagating close is safe because it closes a check-in with no descendants. A landed segment is a leaf by the same-branch rule while still having children on the branch above it. check-in: d97b39b272 user: dmestas tags: strata

Every landed branch stayed an open leaf, which was survivable one landing at a time and is not with stacks: a six-deep stack left seven leaves, and 'leaves' is how you find work that still needs doing.

accept now writes fossil's propagating 'closed' tag on the branch it merged. reject does not -- a rejected branch is one the author may revise and propose again, and closing it would decide that for them.

Best-effort and last, like the retargets: a leaf that stayed open is untidy, never incorrect, and the diagnostic names the command that fixes it. check-in: c9b0147381 user: dmestas tags: strata

A landing may target another branch that has its own open landing; that pair is a stack, read from the targets rather than recorded anywhere. No new card, no dependency field -- the edge is already implied.

Stacks land bottom-up. accept refuses a landing whose target has its own open landing, and accepting one retargets whatever was stacked on it onto the branch it just landed on. That is the whole restack: a metadata write per child, because a segment's branch already descends from the one below it, so after that lands the merge sees only the segment's own change.

Adds 'landing retarget', a target reply resolved by the same latest-wins rule as a state transition. ls indents a stack by depth; show names what a segment sits on, what sits on it, and when its base was rejected.

Verified six deep on a shared file, which is the depth the design claim was previously only reasoned about. check-in: 3767f1eafc user: dmestas tags: strata