* fix(items): undo of an emptied line, and a patch that changes nothing is refused (PLAN-3578)
Retro CONVE-735 findings on #2058 and #2055.
Undo: an edit that deleted a line's only content recorded empty,
line-clipped context on both sides, so its inverse had no anchor and the
undo was refused as an empty anchor. ApplyWithContext now reaches across
the line breaks when the clipped context around an edit that wrote nothing
is empty. A patch that empties the WHOLE body still leaves nothing to
anchor on; its undo now says so and points at History instead of "old is
empty".
No-op: an edit whose old equals its new, or edits that cancel out, used to
answer success and advance seq with no version behind it, against "every
patch is a version". Both are refused 400, writing nothing: per edit up
front in the handler, and the combined case through bodypatch.ErrNoChange
on the no-room path.
Claude-Session: https://claude.ai/code/session_01Q9WssCjFuHjSfLABoW4tmS
* fix(items): a no-op patch through an open editor is refused too (PLAN-3578)
Codex round 1 on d6c3cc381 (P2): edits that cancel out were refused on
the no-room path but still written on the open-editor path, where the ack
branch ignored ErrNoChange and wrote a version and a seq for a no-op. When
the tab's before and after are equal, the patch is now refused with the
same no-change 400, writing nothing.
Claude-Session: https://claude.ai/code/session_01Q9WssCjFuHjSfLABoW4tmS
* docs(api): the patch endpoint's no-op refusal and the emptied-body undo (PLAN-3578)
Claude-Session: https://claude.ai/code/session_01Q9WssCjFuHjSfLABoW4tmS
POST /workspaces/{ws}/items/{ref}/patch {edits:[{old,new,line_hint?}],
expected_seq?} replaces exact text in the body. It runs through updateItem,
so it takes every PATCH guard; the body is computed inside the store
transaction from the row it replaces. Each old must occur exactly once;
edits apply in order, all or nothing; every patch writes a version. The
answer carries a unified diff of what changed.
expected_seq does not refuse: a moved seq is applied over when the
anchors still match, and answered rebased with the intervening writes,
read from a seq chain stamped into item activity entries ({prev_seq, seq,
version_id}). complete is decided at runtime, so any write that left no
stamp reads incomplete; a guard test classifies every seq-moving store
statement. Refusals write nothing: patch_anchor_missing,
patch_anchor_ambiguous, patch_room_open (an open editor; step 2).
CLI: pad item patch, pad item show --lines. MCP 0.87 (additive):
pad_item.patch, get lines, three allow-listed codes. The timeline treats
the chain and patch keys as bookkeeping, not a change.
Claude-Session: https://claude.ai/code/session_01Q9WssCjFuHjSfLABoW4tmS
xarmian