Lifecycle and safety fixes from the external review:
- Observe abort while awaiting the initialize handshake, so a server that never
replies can't defeat the tool-timeout signal.
- On an aborted request the server won't cancel, tear the instance down after a
bounded grace instead of releasing the serialized queue with work still live
(prevents overlapping document lifecycles).
- Re-check provider disposal after the canonicalize/read awaits so a query can't
spawn an unowned server after disposeAll().
- Read the source through one open handle (stat + read on the same fd) to close
the realpath-vs-read TOCTOU; decode with a fatal UTF-8 decoder so a legitimate
U+FFFD is not misclassified as invalid.
- Validate and read the source BEFORE spawning a server (pre-start rejection).
- Require an explicit openClose for option-form textDocumentSync.
- Reject nonpositive teardown budgets and non-executable absolute commands at
load; surface unsupported operations as structured LSP_UNSUPPORTED_OPERATION.
- Retain the stderr tail (fatal diagnostics land at exit), not the prefix.
- Catalog the seam vocabulary in docs/core-data-structures/lsp.md.
Implements the LSP capability seam RFC as three packages: dsh-lsp (the
ctx.lsp interface — provider registry by branded id + exclusive extension
mapping, per-query order-independent selection, closed request/result
vocabulary, LspError taxonomy), dsh-lsp-local (a generic stdio language-server
provider — Content-Length JSON-RPC framing, per-(provider, workspace) process
single-flight, transient didOpen/query/didClose, an abortable per-instance
queue, UTF-16 negotiation, host-namespace source reads outside ctx.fs, and
bounded shutdown/kill teardown), and dsh-tool-lsp (the model-facing lsp tool —
four operations, one-based UTF-16 cursor conversion, workspace-grouped location
rendering, hover capping, a required session workspace, and a timeout budget).
Why: an agent had text search and file reads but no way to identify a program
symbol — follow an alias, connect an interface to implementations, or read an
inferred type — before changing code. Splitting model contract, seam, and local
subprocess behavior keeps the four semantic queries stable across future remote
or sandbox-native providers without leaking a JSON-RPC escape hatch.
Tianyi Cui
Dudu-0223