Review thread on #136050 (agent/context_compressor_telemetry.py, "Refusals
report unsaved effects"). The compressor records a candidate's effect
fields before the commit checks run. When the growth guard refused the
candidate, or a database failure rolled the transcript back, the aborted
record still reported its `messages_after`, `tokens_after`,
`tokens_reclaimed` and `items_dropped`. That claimed reclaimed tokens for a
conversation that stayed unchanged.
Drop those fields from any record that neither committed nor rewrote the
history. The input-side counts stay.
Restore the pre-compression transcript when a context engine raises. Evaluate growth against the immutable input snapshot and defer memory publication until the candidate passes every refusal gate, so in-place mutation cannot bypass refusal or leak side effects.
Signed-off-by: mnajafian-nv <mnajafian@nvidia.com>
(cherry picked from commit 969371c564c172046934b535b3488610171726de)
Context engines may mutate the message list they receive, and the
context-engine plugin guide says that mutation only becomes visible if
the pass commits. Callers that pass their own commit fence (gateway
session hygiene) or set compression.context_timeout_seconds to 0 hand
the live list to the engine without the facade's deep snapshot.
compress_context restored the pre-compression snapshot on the
no-progress and superseded refusals, but the compressor-abort,
empty-transcript and would-grow refusals returned the live list as the
engine left it. An engine that cleared its input and returned [] made
compress_context return an empty transcript while warning that the
conversation continues unchanged.
Restore the snapshot in compress_context whenever _candidate_rejected
refuses a candidate or the commit refuses a grown one, so every refusal
returns the original transcript. The no-progress and superseded
branches no longer restore on their own because the caller now does it
for every refusal. Warnings, telemetry and the commit path are
unchanged.
Signed-off-by: mnajafian-nv <mnajafian@nvidia.com>
(cherry picked from commit d14fc7c96031d15f85acb00d433bcfdd39804554)
