Merge pull request 'The gate takes away an ask once no delivery it covers can still merge by it (issue 774)' (#577) from fix/merge-ask-ends-on-merge into main

modules/mesh-delivery-gate/cmd/mesh-delivery-gate/approval.go

@@ -325,14 +325,17 @@ func (h *Holder) headsHold(d *Delivery, c *ReadyRun) bool {
 
 // endStaleAsks ends every ask whose heads are no longer its group's: a push to any member ends the approval (ADR 0398
 // §3), and says so once on each pull request it covered (ADR 0421 §6). An ask for a head a newer one replaced ends too.
-// A Decline stands, and is not ended. Under the lock; the cancels run with the look's asks.
+// A Decline stands, and is not ended. An ask none of whose deliveries can still merge by it is taken away after
+// (endAsksOfFinished). Under the lock; the cancels run with the look's asks.
 func (h *Holder) endStaleAsks() {
 	h.endStaleSettles()
+	ending := map[string]bool{}
 	for _, d := range h.deliveries {
 		r := d.Ready
 		if r == nil || r.Merged != nil || d.MergedAs != "" || r.declined() || (r.AskID == "" && r.Approved == nil) || len(r.Heads) == 0 {
 			continue
 		}
+		id, before := r.AskID, len(h.cancels)
 		switch {
 		case d.State.Final():
 			h.cancels = append(h.cancels, h.dropAsk(r.AskID, "its head "+shortOf(d.Commit, 12)+" is no longer the pull request's head, or the pull request closed"))
@@ -347,6 +350,61 @@ func (h *Holder) endStaleAsks() {
 			// written again, which the teller asks afresh (ADR 0441 §1).
 			h.cancels = append(h.cancels, h.withdrawAsk(r.AskID, "nobody answered in "+AskLasts.String()))
 		}
+		if id != "" && (len(h.cancels) > before || h.withdrawn[id]) {
+			ending[id] = true
+		}
+	}
+	h.endAsksOfFinished(ending)
+}
+
+// endAsksOfFinished takes away every ask that stands in the gate's asks while none of the deliveries it was asked for can still
+// be merged by it: each merged (on the operator's Approve or by another path) or ended. The ask is about a merge, so it ends
+// once that merge cannot follow from it, however the deliveries got there (issue 774: on 2026-10-31 two pull requests the lead
+// merged once their checks were green left their asks standing for a day, and the teller's asks held two of the router's three
+// places, so a newer ask was refused for want of room). It reads what the gate keeps (AskedKey, Written), so an ask whose
+// taking away failed is taken away again at the next look. An ask another end of this look takes away (ending, withdrawn) is
+// left to it. Nothing is said on a pull request: its merge or its end said it. Under the lock.
+func (h *Holder) endAsksOfFinished(ending map[string]bool) {
+	standing, live := map[string]bool{}, map[string]bool{}
+	for _, d := range h.deliveries {
+		r := d.Ready
+		if r == nil || r.AskedKey == "" {
+			continue
+		}
+		if r.Written {
+			standing[r.AskedKey] = true
+		}
+		if d.MergedAs == "" && !d.State.Final() {
+			live[r.AskedKey] = true
+		}
+	}
+	keys := make([]string, 0, len(standing))
+	for key := range standing {
+		if !live[key] && !ending[key] && !h.withdrawn[key] {
+			keys = append(keys, key)
+		}
+	}
+	sort.Strings(keys)
+	for _, key := range keys {
+		for _, d := range h.deliveries {
+			if r := d.Ready; r != nil && r.AskID == key && r.Approved == nil {
+				r.AskID, r.Ask, r.Heads = "", nil, nil
+				h.keep(d)
+			}
+		}
+		h.Logf("[mesh-delivery] the operator's ask %s is taken away: every pull request it was asked for is merged or ended", key)
+		if h.Operator == nil {
+			continue
+		}
+		h.cancels = append(h.cancels, func() {
+			if err := h.Operator.Cancel(key); err != nil {
+				h.Logf("[mesh-delivery] the operator's ask %s could not be taken away, and is taken away at the next look (%v)", key, err)
+				return
+			}
+			h.mu.Lock()
+			h.markWritten(key, false)
+			h.mu.Unlock()
+		})
 	}
 }
 

modules/mesh-delivery-gate/cmd/mesh-delivery-gate/approval_test.go

@@ -160,6 +160,27 @@ func TestAPushAfterTheAskCancelsItAndTheNewHeadIsAskedOnItsOwnWhenItsChecksPass(
 	if open := w.op.open(); len(open) != 1 || open[0] == old {
 		t.Fatalf("the new head was not asked afresh: %v", open)
 	}
+	// Issue 774 (2026-10-31): a pull request merged by another path than the Approve (the lead merged it once its check was
+	// green) left its ask in the gate's asks for a day, and the teller's ask held one of the router's three places. An ask whose
+	// every delivery is merged or ended is taken away at the next look, saying nothing on the pull request.
+	t.Run("774: an ask whose pull request merged without it is taken away", func(t *testing.T) {
+		w := markedGreen(t)
+		ask := w.op.open()[0]
+		comments := len(w.forge.comments)
+		w.h.PullMerged(merged("novox/app", 7, readyHead, "m1m1m1m1m1m1m1m1m1m1m1m1m1m1m1m1m1m1m1m1"))
+		w.settleAll()
+		if len(w.op.open()) != 0 || len(w.op.cancelled) != 1 || w.op.cancelled[0] != ask {
+			t.Fatalf("the ask of a merged pull request stands: open %v, taken away %v", w.op.open(), w.op.cancelled)
+		}
+		if d := w.delivery(IDOf("novox/app", readyHead)); d.Ready.AskID != "" || d.Ready.Written {
+			t.Errorf("the merged delivery still keeps its ask: %+v", d.Ready)
+		}
+		w.later(2 * time.Minute)
+		w.settleAll()
+		if len(w.op.cancelled) != 1 || w.op.count() != 1 || len(w.forge.comments) != comments {
+			t.Errorf("taken away %v, asks %d, comments %v: once, asking nothing again, saying nothing", w.op.cancelled, w.op.count(), w.forge.comments[comments:])
+		}
+	})
 }
 
 // The ask lapses at the router after AskLasts with nobody's answer, and the gate has no word of it: it takes its key away and

modules/mesh-delivery-gate/cmd/mesh-delivery-gate/settle.go

@@ -98,11 +98,31 @@ func (h *Holder) Settle(ids []string, why, by string) (map[string]any, error) {
 		}
 	}
 	ask := sdk.Ask{Group: group, Heads: heads, Asking: asking, Ask: composeSettleAsk(sdk.AskingID(key, asking), covered, why, now)}
+	earlier := map[string]bool{}
 	for _, d := range covered {
+		if d.Settle != nil && d.Settle.Answered == nil && d.Settle.Key != key {
+			earlier[d.Settle.Key] = true
+		}
 		d.Settle = &SettleAsk{Key: key, Asking: asking, Why: why, By: by, At: now}
 		h.keep(d)
 	}
+	// An earlier settle ask of another set that no delivery waits for any more is taken away (issue 774): its question is
+	// gone, and left standing it would hold the teller's room at the router until it lapsed.
+	for _, d := range h.deliveries {
+		if d.Settle != nil {
+			delete(earlier, d.Settle.Key)
+		}
+	}
+	gone := make([]string, 0, len(earlier))
+	for k := range earlier {
+		gone = append(gone, k)
+	}
+	sort.Strings(gone)
 	h.mu.Unlock()
+	for _, k := range gone {
+		h.Logf("[mesh-delivery] the settle ask %s is taken away: settle asked again for another set, and no delivery waits for it", k)
+		h.cancelSettle(k)()
+	}
 	if err := h.Operator.Ask(key, ask); err != nil {
 		return nil, fmt.Errorf("the settle ask %s could not be written (call settle again): %w", key, err)
 	}

modules/mesh-delivery-gate/cmd/mesh-delivery-gate/settle_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"slices"
 	"strings"
 	"testing"
 	"time"
@@ -110,4 +111,17 @@ func TestSettleAsksTheOperatorOnceAndMovesOnlyOnTheAnswer(t *testing.T) {
 	if c.State != Held || c.Settle.Answer != "lapsed" {
 		t.Errorf("a lapsed settle ask: %s %+v", c.State, c.Settle)
 	}
+	// Issue 774: a settle asked again for another set of deliveries is another key; the earlier ask, which no delivery waits
+	// for any more, is taken away at once, not left to hold the teller's room at the router until it lapses.
+	e, f := put("novox/web@eeeeeeeeeeee", Held, HeldUnchecked), put("novox/web@ffffffffffff", Held, HeldUnchecked)
+	first, err := w.h.Settle([]string{e.ID}, "one", aPerson)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := w.h.Settle([]string{e.ID, f.ID}, "both", aPerson); err != nil {
+		t.Fatal(err)
+	}
+	if k := first["asked"].(string); !slices.Contains(w.op.cancelled, k) || slices.Contains(w.op.open(), k) {
+		t.Errorf("the earlier settle ask %s stands once no delivery waits for it: open %v, taken away %v", k, w.op.open(), w.op.cancelled)
+	}
 }