modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge-tools/main.go

@@ -8,7 +8,9 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"maps"
 	"os"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -17,6 +19,9 @@ import (
 	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 
+	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-forge-bridge/forgemsg"
+
+	"mesh-delivery-forge-bridge/internal/bridge"
 	"mesh-delivery-forge-bridge/internal/groups"
 )
 
@@ -24,15 +29,34 @@ import (
 const (
 	GroupsTool   = "bridge_groups"
 	EndAgainTool = "bridge_group_end_again"
+	// MergedTool answers the merged message of a merge on request (issue 1585).
+	MergedTool = "bridge_merged_message"
 )
 
 // asker writes an end-asks value and waits for the bridge's answer to it.
 type asker func(key string, value []byte) (groups.EndAsk, error)
 
 // Tools are the bridge's tools: groupsRead reads the groups the gate holds with what the bridge kept of them.
-func Tools(ask asker, now func() time.Time, groupsRead func() ([]groups.Row, []string, error)) []stdio.Tool {
+func Tools(ask asker, now func() time.Time, groupsRead func() ([]groups.Row, []string, error), merged func(repository, merge string) (json.RawMessage, error)) []stdio.Tool {
 	str := func(args map[string]any, k string) string { s, _ := args[k].(string); return strings.TrimSpace(s) }
 	return []stdio.Tool{
+		{Name: MergedTool,
+			Description: "The merged message of one merge, asked again (issue 1585): the message the bridge wrote on its stream FORGE when the " +
+				"pull request was merged into the trunk, built the same way from the forge (the merge commit's trees and the manifests " +
+				"and lock files of its module directories) and from the gate's merges state (the pull request's number, head and " +
+				"group). For the indexer, which asks it when it takes in a held merge it does not hold in memory (a restart, a new " +
+				"build), and the ask-again a lost message lacked. About 0.5 MB for a repository of many modules. Answers {message} " +
+				"with the forge message whole, or why it cannot: the gate holds no merge with that commit, or the forge did not answer.",
+			Input: map[string]any{"type": "object", "required": []string{"repository", "merge"}, "properties": map[string]any{
+				"repository": map[string]any{"type": "string", "description": "the repository, owner/name, as the forge names it"},
+				"merge":      map[string]any{"type": "string", "description": "the merge commit, 40 hex digits"}}},
+			Run: func(args map[string]any) (any, error) {
+				raw, err := merged(str(args, "repository"), str(args, "merge"))
+				if err != nil {
+					return nil, err
+				}
+				return map[string]any{"message": raw}, nil
+			}},
 		{Name: GroupsTool,
 			Description: "The delivery groups the gate holds (more than one member), each with its members' merge state and whether each " +
 				"merged message is written on the forge stream, and whether the group's end (forge.group.merged) is written: ended, " +
@@ -81,6 +105,43 @@ func Tools(ask asker, now func() time.Time, groupsRead func() ([]groups.Row, []s
 	}
 }
 
+// MergedOf is the merged message of the merge of repository at commit merge, as the bridge writes it: the pull request's
+// number, head and group from the gate's merges (raw, by key), the rest from the forge through trees and files
+// (bridge.MergedMessage), and, for a member of a delivery group, the group and its members as the process sets them.
+func MergedOf(raws map[string][]byte, repository, merge string, trees bridge.Trees, files bridge.Files) (json.RawMessage, error) {
+	owner, repo, ok := strings.Cut(repository, "/")
+	if !ok || owner == "" || repo == "" {
+		return nil, fmt.Errorf("%q is not owner/name", repository)
+	}
+	for _, key := range slices.Sorted(maps.Keys(raws)) {
+		m, err := delivery.DecodeMerge(raws[key])
+		if err != nil {
+			continue
+		}
+		at := slices.IndexFunc(m.Pulls, func(p delivery.MergePull) bool {
+			return delivery.SameRepository(p.Repository, repository) && p.Commit == merge
+		})
+		if at < 0 {
+			continue
+		}
+		p := m.Pulls[at]
+		msg, err := bridge.MergedMessage(owner, repo, p.Number, m.Group, p.Head.Head, merge, trees, files)
+		if err != nil {
+			return nil, fmt.Errorf("the merged message of %s at %s cannot be built: %w", repository, merge, err)
+		}
+		f, err := forgemsg.DecodeForge(msg.Data)
+		if err != nil {
+			return nil, err
+		}
+		if _, approved := m.Approved[delivery.ApprovedKey(f.Repository, f.Number)]; approved && len(m.Approved) >= 2 {
+			f.Group, f.Members = m.Group, groups.MembersOf(m)
+		}
+		out, err := forgemsg.EncodeForge(f)
+		return out, err
+	}
+	return nil, fmt.Errorf("the gate's merges hold no merge of %s with the commit %s, so its pull request is not known", repository, merge)
+}
+
 // read is the groups the gate holds with what the bridge kept of them: their ends in performed, and the last ask of
 // each in end-asks with the bridge's answer.
 func read(merges, performed, asks stdio.KeptState) ([]groups.Row, []string, error) {
@@ -175,10 +236,29 @@ func askEnd(s stdio.KeptState, bound time.Duration) asker {
 	}
 }
 
+// askCaller calls a tool as this bundle's module, through the runtime (stdio.Ask), the module's own invokes granting it.
+func askCaller(_ context.Context, key string, body any) (json.RawMessage, error) {
+	return stdio.Ask(key, body)
+}
+
 func main() {
 	merges, performed, asks := stdio.State(delivery.GateModule+".merges"), stdio.State(groups.PerformedState), stdio.State(groups.EndAsksState)
 	tools := Tools(askEnd(asks, 25*time.Second), time.Now,
-		func() ([]groups.Row, []string, error) { return read(merges, performed, asks) })
+		func() ([]groups.Row, []string, error) { return read(merges, performed, asks) },
+		func(repository, merge string) (json.RawMessage, error) {
+			keys, err := merges.Keys()
+			if err != nil {
+				return nil, fmt.Errorf("the gate's merges cannot be listed: %w", err)
+			}
+			raws := map[string][]byte{}
+			for _, k := range keys {
+				if e, err := merges.Get(k); err == nil && e != nil {
+					raws[k] = e.Value
+				}
+			}
+			ctx := context.Background()
+			return MergedOf(raws, repository, merge, bridge.TreesVia(ctx, askCaller), bridge.FilesVia(ctx, askCaller))
+		})
 	if err := stdio.Serve("", tools); err != nil {
 		fmt.Fprintf(os.Stderr, "[mesh-delivery-forge-bridge-tools] %v\n", err)
 		os.Exit(1)

modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge-tools/main_test.go

@@ -1,13 +1,18 @@
 package main
 
 import (
+	"bytes"
 	"encoding/json"
+	"errors"
 	"strings"
 	"testing"
 	"time"
 
+	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-forge-bridge/forgemsg"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 
+	"mesh-delivery-forge-bridge/internal/bridge"
+
 	"mesh-delivery-forge-bridge/internal/groups"
 )
 
@@ -51,7 +56,7 @@ func TestTheBridgeToolsReadTheGroupsAndAskTheEndAgain(t *testing.T) {
 		func() ([]groups.Row, []string, error) {
 			rows, unread := groups.Rows(merges, performed, map[string]uint64{"ended": 7}, asks)
 			return rows, unread, nil
-		})
+		}, nil)
 	call := func(name string, args map[string]any) any {
 		for _, tl := range tools {
 			if tl.Name == name {
@@ -113,4 +118,73 @@ func TestTheBridgeToolsReadTheGroupsAndAskTheEndAgain(t *testing.T) {
 			}
 		}
 	}
+
+	// 1585: bridge_merged_message answers the merged message as the bridge publishes it: for a lone pull request the same bytes
+	// the event gives through Convert, for a member of a delivery group those with its group and members set as the process
+	// sets them; a merge the gate does not hold, or a forge that does not answer, is said.
+	t.Run("bridge_merged_message answers the merged message as published", func(t *testing.T) {
+		h1, h2 := strings.Repeat("1", 40), strings.Repeat("2", 40)
+		c1, c2 := strings.Repeat("c", 40), strings.Repeat("d", 40)
+		trees := func(owner, repo, sha string) (string, map[string]string, error) {
+			return "root-" + sha[:4], map[string]string{"": "r", "modules/a": "ta-" + sha[:4]}, nil
+		}
+		files := func(owner, repo, path, ref string) ([]byte, error) {
+			if strings.HasSuffix(path, "module.json") {
+				return []byte(`{"module":"a"}`), nil
+			}
+			return nil, bridge.ErrNotFound
+		}
+		published := func(repo string, number int, head, branch, merge string) forgemsg.Forge {
+			body, _ := json.Marshal(map[string]any{"owner": "novox", "repo": repo, "number": number, "head": branch, "head_sha": head, "base": "main", "merge_commit_sha": merge})
+			msg, err := bridge.Convert(bridge.MergedSubject, body, trees, files)
+			if err != nil {
+				t.Fatal(err)
+			}
+			f, err := forgemsg.DecodeForge(msg.Data)
+			if err != nil {
+				t.Fatal(err)
+			}
+			return f
+		}
+		lone, _ := delivery.EncodeMerge(delivery.Merge{Group: "solo", Ask: "a", Approved: map[string]string{"novox/a@5": h1},
+			Pulls: []delivery.MergePull{{Head: delivery.Head{Repository: "novox/a", Number: 5, Head: h1}, State: delivery.MergeMerged, Commit: c1}}})
+		group, _ := delivery.EncodeMerge(delivery.Merge{Group: "feat/g", Ask: "a", Approved: map[string]string{"novox/a@6": h1, "novox/b@7": h2},
+			Pulls: []delivery.MergePull{{Head: delivery.Head{Repository: "novox/a", Number: 6, Head: h1}, State: delivery.MergeMerged, Commit: c1},
+				{Head: delivery.Head{Repository: "novox/b", Number: 7, Head: h2}, State: delivery.MergeMerging}}})
+		for _, c := range []struct {
+			name       string
+			raws       map[string][]byte
+			repository string
+			merge      string
+			want       forgemsg.Forge
+			fail       string
+		}{
+			{name: "a lone pull request", raws: map[string][]byte{"solo": lone}, repository: "novox/a", merge: c1, want: published("a", 5, h1, "solo", c1)},
+			{name: "a member of a group", raws: map[string][]byte{"feat~g": group}, repository: "novox/a", merge: c1, want: func() forgemsg.Forge {
+				f := published("a", 6, h1, "feat/g", c1)
+				f.Group, f.Members = "feat/g", []delivery.Head{{Repository: "novox/a", Number: 6, Head: h1}, {Repository: "novox/b", Number: 7, Head: h2}}
+				return f
+			}()},
+			{name: "a merge the gate does not hold", raws: map[string][]byte{"solo": lone, "bad": []byte("{")}, repository: "novox/a", merge: c2, fail: "hold no merge"},
+		} {
+			t.Run(c.name, func(t *testing.T) {
+				raw, err := MergedOf(c.raws, c.repository, c.merge, trees, files)
+				if c.fail != "" {
+					if err == nil || !strings.Contains(err.Error(), c.fail) {
+						t.Fatalf("err %v, want %q", err, c.fail)
+					}
+					return
+				}
+				want, _ := forgemsg.EncodeForge(c.want)
+				if err != nil || !bytes.Equal(raw, want) {
+					t.Fatalf("err %v, answer\n%s\nwant the published message\n%s", err, raw, want)
+				}
+			})
+		}
+		if _, err := MergedOf(map[string][]byte{"solo": lone}, "novox/a", c1, func(string, string, string) (string, map[string]string, error) {
+			return "", nil, errors.New("the forge does not answer")
+		}, files); err == nil || !strings.Contains(err.Error(), "does not answer") {
+			t.Errorf("a forge that does not answer: %v", err)
+		}
+	})
 }

modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge/call.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"regexp"
 	"strings"
 	"time"
 
@@ -66,58 +65,12 @@ func callerOn(nc *nats.Conn, user string) caller {
 	}
 }
 
-// commitTreesTool is the forge's tool for a commit's trees (mesh-catalog modules/gitea, issue 1234): arguments owner,
-// repo and sha, answer {root, trees}, the root directory spelled "" (1234/AC4).
-const commitTreesTool = "gitea.gitea_commit_trees"
-
 // treesVia asks the forge for a commit's trees through call.
 func treesVia(ctx context.Context, call caller) bridge.Trees {
-	return func(owner, repo, sha string) (string, map[string]string, error) {
-		raw, err := call(ctx, commitTreesTool, map[string]string{"owner": owner, "repo": repo, "sha": sha})
-		if err != nil {
-			return "", nil, err
-		}
-		var a struct {
-			Root  string            `json:"root"`
-			Trees map[string]string `json:"trees"`
-		}
-		if err := json.Unmarshal(raw, &a); err != nil {
-			return "", nil, fmt.Errorf("the answer of %s is not {root, trees}: %w", commitTreesTool, err)
-		}
-		if a.Root == "" {
-			return "", nil, fmt.Errorf("the answer of %s names no root tree", commitTreesTool)
-		}
-		return a.Root, a.Trees, nil
-	}
+	return bridge.TreesVia(ctx, bridge.Caller(call))
 }
 
-// getFileTool is the forge's tool for one file at a ref (mesh-catalog modules/gitea tools/index.ts gitea_get_file):
-// arguments owner, repo, path and ref, answer {file: {path, ref, sha, size, content}}, the content decoded to text
-// (client.ts getFile). A path the forge does not have fails with `Gitea API <path>: 404 <body>` (client.ts request).
-const getFileTool = "gitea.gitea_get_file"
-
-// notFound is how the forge's error says 404 (client.ts request: `Gitea API ${path}: ${status} ${text}`; client.ts:670
-// recognises it as /: 404 /).
-var notFound = regexp.MustCompile(`: 404 `)
-
 // filesVia asks the forge for a file through call. A file the forge says is not there is bridge.ErrNotFound.
 func filesVia(ctx context.Context, call caller) bridge.Files {
-	return func(owner, repo, path, ref string) ([]byte, error) {
-		raw, err := call(ctx, getFileTool, map[string]string{"owner": owner, "repo": repo, "path": path, "ref": ref})
-		if err != nil {
-			if notFound.MatchString(err.Error()) {
-				return nil, fmt.Errorf("%w: %v", bridge.ErrNotFound, err)
-			}
-			return nil, err
-		}
-		var a struct {
-			File *struct {
-				Content *string `json:"content"`
-			} `json:"file"`
-		}
-		if err := json.Unmarshal(raw, &a); err != nil || a.File == nil || a.File.Content == nil {
-			return nil, fmt.Errorf("the answer of %s is not {file: {content}}: %v", getFileTool, err)
-		}
-		return []byte(*a.File.Content), nil
-	}
+	return bridge.FilesVia(ctx, bridge.Caller(call))
 }

modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge/groups.go

@@ -5,8 +5,6 @@ import (
 	"errors"
 	"log"
 	"slices"
-	"strconv"
-	"strings"
 
 	"github.com/nats-io/nats.go/jetstream"
 
@@ -86,29 +84,6 @@ func (g *grouper) groupOf(ctx context.Context, f forgemsg.Forge) (delivery.Merge
 	return m, rev, true
 }
 
-// membersOf are a merge's approved members with their heads, in the order of their keys.
-func membersOf(m delivery.Merge) []delivery.Head {
-	var out []delivery.Head
-	for _, k := range slices.Sorted(func(yield func(string) bool) {
-		for k := range m.Approved {
-			if !yield(k) {
-				return
-			}
-		}
-	}) {
-		at := strings.LastIndex(k, "@")
-		if at < 0 {
-			continue
-		}
-		n, err := strconv.Atoi(k[at+1:])
-		if err != nil {
-			continue
-		}
-		out = append(out, delivery.Head{Repository: k[:at], Number: n, Head: m.Approved[k]})
-	}
-	return out
-}
-
 // member sets the group and its approved members on a merged message's body (ADR 0633 §4); any other body, and a
 // merge of no group, is left as it is.
 func (g *grouper) member(ctx context.Context, data []byte) ([]byte, forgemsg.Forge, bool) {
@@ -120,7 +95,7 @@ func (g *grouper) member(ctx context.Context, data []byte) ([]byte, forgemsg.For
 	if !ok {
 		return data, f, false
 	}
-	f.Group, f.Members = m.Group, membersOf(m)
+	f.Group, f.Members = m.Group, groupkeys.MembersOf(m)
 	out, err := forgemsg.EncodeForge(f)
 	if err != nil {
 		g.logger.Printf("%s#%d: its merged message cannot name the group %q, written without: %v", f.Repository, f.Number, m.Group, err)
@@ -165,7 +140,7 @@ func (g *grouper) end(ctx context.Context, key string, rev uint64, value []byte,
 		}
 	}
 	end := forgemsg.ForgeGroupEnd{Group: m.Group}
-	for _, member := range membersOf(m) {
+	for _, member := range groupkeys.MembersOf(m) {
 		at := slices.IndexFunc(m.Pulls, func(p delivery.MergePull) bool {
 			return delivery.SameRepository(p.Repository, member.Repository) && p.Number == member.Number
 		})

modules/mesh-delivery-forge-bridge/internal/bridge/call.go

@@ -0,0 +1,79 @@
+package bridge
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"regexp"
+)
+
+// Caller calls a module's tool by its manifest key (`<module>.<tool>`) with a JSON body and returns the tool's result:
+// the bridge's process calls through the bus as its own principal, its tools bundle through the runtime (stdio.Ask).
+type Caller func(ctx context.Context, key string, body any) (json.RawMessage, error)
+
+// CommitTreesTool is the forge's tool for a commit's trees (mesh-catalog modules/gitea, issue 1234): arguments owner,
+// repo and sha, answer {root, trees}, the root directory spelled "" (1234/AC4).
+const CommitTreesTool = "gitea.gitea_commit_trees"
+
+// TreesVia asks the forge for a commit's trees through call.
+func TreesVia(ctx context.Context, call Caller) Trees {
+	return func(owner, repo, sha string) (string, map[string]string, error) {
+		raw, err := call(ctx, CommitTreesTool, map[string]string{"owner": owner, "repo": repo, "sha": sha})
+		if err != nil {
+			return "", nil, err
+		}
+		var a struct {
+			Root  string            `json:"root"`
+			Trees map[string]string `json:"trees"`
+		}
+		if err := json.Unmarshal(raw, &a); err != nil {
+			return "", nil, fmt.Errorf("the answer of %s is not {root, trees}: %w", CommitTreesTool, err)
+		}
+		if a.Root == "" {
+			return "", nil, fmt.Errorf("the answer of %s names no root tree", CommitTreesTool)
+		}
+		return a.Root, a.Trees, nil
+	}
+}
+
+// GetFileTool is the forge's tool for one file at a ref (mesh-catalog modules/gitea tools/index.ts gitea_get_file):
+// arguments owner, repo, path and ref, answer {file: {path, ref, sha, size, content}}, the content decoded to text
+// (client.ts getFile). A path the forge does not have fails with `Gitea API <path>: 404 <body>` (client.ts request).
+const GetFileTool = "gitea.gitea_get_file"
+
+// notFound is how the forge's error says 404 (client.ts request: `Gitea API ${path}: ${status} ${text}`; client.ts:670
+// recognises it as /: 404 /).
+var notFound = regexp.MustCompile(`: 404 `)
+
+// FilesVia asks the forge for a file through call. A file the forge says is not there is ErrNotFound.
+func FilesVia(ctx context.Context, call Caller) Files {
+	return func(owner, repo, path, ref string) ([]byte, error) {
+		raw, err := call(ctx, GetFileTool, map[string]string{"owner": owner, "repo": repo, "path": path, "ref": ref})
+		if err != nil {
+			if notFound.MatchString(err.Error()) {
+				return nil, fmt.Errorf("%w: %v", ErrNotFound, err)
+			}
+			return nil, err
+		}
+		var a struct {
+			File *struct {
+				Content *string `json:"content"`
+			} `json:"file"`
+		}
+		if err := json.Unmarshal(raw, &a); err != nil || a.File == nil || a.File.Content == nil {
+			return nil, fmt.Errorf("the answer of %s is not {file: {content}}: %v", GetFileTool, err)
+		}
+		return []byte(*a.File.Content), nil
+	}
+}
+
+// MergedMessage is the merged message of a merge into the trunk, asked again: built as the bridge builds the one it writes
+// on FORGE (it is that event's body through ConvertKept), from the pull request's owner, repository, number, branch, head
+// and merge commit, which the gate's merges state holds. It reads the forge for every module directory (no kept inputs).
+func MergedMessage(owner, repo string, number int, branch, head, merge string, trees Trees, files Files) (Message, error) {
+	body, err := json.Marshal(pull{Owner: owner, Repo: repo, Number: number, Head: branch, HeadSHA: head, Base: Trunk, MergeSHA: merge})
+	if err != nil {
+		return Message{}, err
+	}
+	return ConvertKept(MergedSubject, body, trees, files, nil)
+}

modules/mesh-delivery-forge-bridge/internal/groups/groups.go

@@ -10,7 +10,9 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"slices"
 	"sort"
+	"strconv"
 	"strings"
 	"time"
 
@@ -171,3 +173,26 @@ func Rows(merges map[string][]byte, performed map[string]bool, endedAt map[strin
 }
 
 func sortRows(rows []Row) { sort.Slice(rows, func(i, j int) bool { return rows[i].Key < rows[j].Key }) }
+
+// MembersOf are a merge's approved members with their heads, in the order of their keys.
+func MembersOf(m delivery.Merge) []delivery.Head {
+	var out []delivery.Head
+	for _, k := range slices.Sorted(func(yield func(string) bool) {
+		for k := range m.Approved {
+			if !yield(k) {
+				return
+			}
+		}
+	}) {
+		at := strings.LastIndex(k, "@")
+		if at < 0 {
+			continue
+		}
+		n, err := strconv.Atoi(k[at+1:])
+		if err != nil {
+			continue
+		}
+		out = append(out, delivery.Head{Repository: k[:at], Number: n, Head: m.Approved[k]})
+	}
+	return out
+}

modules/mesh-delivery-forge-bridge/manifest_test.go

@@ -112,8 +112,8 @@ func TestManifestDeclarations(t *testing.T) { // 1235/AC1
 	if !reflect.DeepEqual(m.State, []state{{Name: "heads", History: 1}, {Name: "performed", History: 1}, {Name: "inputs", History: 1}, {Name: "end-asks", History: 1}}) { // 1279/AC6, 1341, 1126, 1585
 		t.Errorf("state = %+v, want the buckets heads, performed, inputs and end-asks", m.State)
 	}
-	// 1585/T18: the tools read the groups and ask the bridge to say a group's end again, through its state end-asks.
-	if want := []string{"bridge_group_end_again", "bridge_groups"}; !reflect.DeepEqual(sorted(m.Tools), want) {
+	// 1585/T18: the tools read the groups and ask the bridge to say a group's end again, through its state end-asks. The tool bridge_merged_message answers a merge's merged message again (issue 1585).
+	if want := []string{"bridge_group_end_again", "bridge_groups", "bridge_merged_message"}; !reflect.DeepEqual(sorted(m.Tools), want) {
 		t.Errorf("tools = %v, want %v", m.Tools, want)
 	}
 	// No other state, no bus, no seat, no event (ADR 0437 §4; ADR 0521: no check.status).

modules/mesh-delivery-forge-bridge/module.json

@@ -18,7 +18,8 @@
   ],
   "tools": [
     "bridge_groups",
-    "bridge_group_end_again"
+    "bridge_group_end_again",
+    "bridge_merged_message"
   ],
   "reads": [
     "mesh-delivery-gate.merges",

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/bridgemessage.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+// mergedTool is the forge bridge's tool that answers a merge's merged message again (issue 1585): arguments repository
+// and merge, answer {message}, the message whole as the bridge writes it on FORGE. The indexer's manifest lists it in
+// invokes, which is the grant to call it.
+const mergedTool = delivery.ForgeBridgeModule + ".bridge_merged_message"
+
+// messageVia asks the forge bridge for a merge's merged message, for a held merge the indexer does not hold in memory (a
+// restart, a new build). An error is the bridge's own words.
+func messageVia(call toolCaller) func(ctx context.Context, repository, merge string) ([]byte, error) {
+	return func(_ context.Context, repository, merge string) ([]byte, error) {
+		raw, err := call(mergedTool, map[string]string{"repository": repository, "merge": merge})
+		if err != nil {
+			return nil, err
+		}
+		var a struct {
+			Message json.RawMessage `json:"message"`
+		}
+		if err := json.Unmarshal(raw, &a); err != nil || len(a.Message) == 0 {
+			return nil, fmt.Errorf("the answer of %s is not {message}: %v", mergedTool, err)
+		}
+		return a.Message, nil
+	}
+}

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/integration_test.go

@@ -11,6 +11,7 @@ import (
 	"path/filepath"
 	"slices"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
@@ -62,6 +63,9 @@ func TestIndexerWhole(t *testing.T) { // 1238/AC2, AC10; 1585/T14, T15
 	var running atomic.Pointer[string]
 	first := "fp-the-indexer-that-runs"
 	running.Store(&first)
+	// The forge bridge's tool bridge_merged_message (issue 1585): answers the merged message published for a merge, by
+	// repository@merge, as the bridge does; a restarted indexer holds none in memory and asks it.
+	var bridgeMessages sync.Map
 	js, ctx, candidates, _, restart := startIndexerRun(t, func(ctx context.Context, builds buildLog) {
 		// The builder's log entries of two builds' ends (ADR 0571 clause 1), as the builder appends them.
 		builds.end(t, "novox/mesh-delivery", "a", "modules/a")
@@ -97,6 +101,23 @@ func TestIndexerWhole(t *testing.T) { // 1238/AC2, AC10; 1585/T14, T15
 			raw, _ := json.Marshal(map[string]any{"result": map[string]any{"runs": map[string]string{"fp": *running.Load()}}, "node": "n1"})
 			_ = m.Respond(raw)
 		}
+		bridge := func(m *nats.Msg) {
+			var ask struct{ Repository, Merge string }
+			_ = json.Unmarshal(m.Data, &ask)
+			data, ok := bridgeMessages.Load(ask.Repository + "@" + ask.Merge)
+			if !ok {
+				raw, _ := json.Marshal(map[string]any{"error": "the gate holds no merge of " + ask.Repository + " with that commit"})
+				_ = m.Respond(raw)
+				return
+			}
+			raw, _ := json.Marshal(map[string]any{"result": map[string]any{"message": json.RawMessage(data.([]byte))}, "node": "n1"})
+			_ = m.Respond(raw)
+		}
+		for _, subject := range []string{"mesh.mod.mesh-delivery-forge-bridge.call.bridge_merged_message.>", "mesh.mod.mesh-delivery-forge-bridge.tool.bridge_merged_message"} {
+			if _, err := js.Conn().Subscribe(subject, bridge); err != nil {
+				t.Fatal(err)
+			}
+		}
 		for _, subject := range []string{"mesh.seat.node-engine.call.composition.n1.>", "mesh.seat.node-engine.tool.composition.n1"} {
 			if _, err := js.Conn().Subscribe(subject, answer); err != nil {
 				t.Fatal(err)
@@ -157,6 +178,7 @@ func TestIndexerWhole(t *testing.T) { // 1238/AC2, AC10; 1585/T14, T15
 			t.Fatal(err)
 		}
 		event, _ := forgemsg.ForgeEvent(f.Repository, forgemsg.ForgeMerged)
+		bridgeMessages.Store(f.Repository+"@"+f.Merge, data)
 		ack, err := js.Publish(ctx, "mesh.stream.mesh-delivery-forge-bridge.event."+event, data)
 		if err != nil {
 			t.Fatal(err)

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/main.go

@@ -348,7 +348,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 		Predefined: awaitedStore{predefined}, ConfigCandidates: awaitedStore{configCandidates}, Logf: logger.Printf,
 		Named: namedVia(calls.Call), Trunk: trunkVia(calls.Call), Contains: containsVia(calls.Call), Read: readVia(calls.Call),
 		ReadOpen: openVia(calls.Call), Packages: awaitedStore{packages}, Files: filesVia(calls.Call), GoSum: goSumVia(calls.Call), GoMod: goModVia(calls.Call),
-		OwnBuild: ownBuildVia(calls.Call, cred.Node), Graph: awaitedStore{graph},
+		OwnBuild: ownBuildVia(calls.Call, cred.Node), Graph: awaitedStore{graph}, Message: messageVia(calls.Call),
 		// The take-in step (ADR 0633): its state pending and its stream take-in, both this delivery's, bound when they appear;
 		// until then every merge is taken in at once, as before.
 		Pending:   awaitedStore{process.AwaitBucket(ctx, js, conn, index.PendingBucket, "no merge is held for the indexer its revision names: each is taken in at once", logger.Printf)},

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/takein.go

@@ -18,6 +18,7 @@ type takerIn interface {
 	JudgeAgain(ctx context.Context, module, digest string) index.TakenIn
 	TakeInPendingByHand(ctx context.Context, key, by, why string) index.TakenIn
 	DropPending(ctx context.Context, key, by, why string) index.TakenIn
+	TakeInMerge(ctx context.Context, repository, merge string, seq uint64, by, why string) index.TakenIn
 }
 
 // takenIn answers one value of the takeins state (the tool indexer_take_in, issue 1945): a value not yet answered takes the
@@ -36,7 +37,10 @@ func takenIn(ctx context.Context, ix takerIn, kv jetstream.KeyValue, e jetstream
 		return
 	}
 	asked, r := "take-in", index.TakenIn{}
-	if a.Pending != "" && a.Drop {
+	if a.Merge != "" {
+		asked, r = "hand take-in of a merge", ix.TakeInMerge(ctx, a.MergeRepository, a.Merge, a.Sequence, a.By, a.Why)
+		a.Module = r.Module
+	} else if a.Pending != "" && a.Drop {
 		asked, r = "drop of a pending merge", ix.DropPending(ctx, a.Pending, a.By, a.Why)
 		a.Module = a.Pending
 	} else if a.Pending != "" {

modules/mesh-delivery-indexer/internal/index/candidates.go

@@ -123,6 +123,11 @@ type Indexer struct {
 	ownMu        sync.Mutex  // guards ownFP
 	ownFP        string      // the fingerprint of the build this program runs, asked at the start pass (learnOwnBuild)
 	judgePending atomic.Bool // the start's judge pass failed: judged again at the next message (verdicts.go)
+	// Message asks the forge bridge for the merged message of a merge, repository and merge commit in, the message whole out (a
+	// pending value keeps a reference, not a copy: issue 1585); an error is the bridge's words. Nil asks none.
+	Message func(ctx context.Context, repository, merge string) ([]byte, error)
+	heldMu  sync.Mutex
+	held    map[uint64]forgemsg.Forge // the merged messages Arrive was handed, by stream sequence, until their merge is taken in or dropped
 	// Pending is the state of merges held for the indexer their revision names (pending.go, novox/hq ADR 0633 §1); nil
 	// takes every merge in at once, as before the take-in step.
 	Pending Store
@@ -215,15 +220,26 @@ func (ix *Indexer) ApplyMessage(ctx context.Context, f forgemsg.Forge) (Applied,
 			ix.logf("%s#%d: its config declarations are not written: %v", f.Repository, f.Number, err)
 		}
 	}
+	return applied, ix.writeCandidate(ctx, f, digests, held)
+}
+
+// removeCandidate takes a merged pull request out of its group's candidate and writes nothing else of its message: for a
+// merge a newer merge of the same repository covers (it needs only the repository, number and branch).
+func (ix *Indexer) removeCandidate(ctx context.Context, f forgemsg.Forge) error {
+	return ix.writeCandidate(ctx, f, nil, nil)
+}
+
+// writeCandidate writes the group's candidate with the pull request f names (taken out for a merged or closed one).
+func (ix *Indexer) writeCandidate(ctx context.Context, f forgemsg.Forge, digests map[string]string, held map[string]delivery.Module) error {
 	if trunkLike[f.Branch] {
 		ix.logf("%s#%d: its branch %q is no delivery group, so no candidate", f.Repository, f.Number, f.Branch)
-		return applied, nil
+		return nil
 	}
 	key, err := delivery.CandidatesKey(f.Branch)
 	if err != nil {
-		return applied, fmt.Errorf("%w: %s#%d: %v", ErrUnreadable, f.Repository, f.Number, err)
+		return fmt.Errorf("%w: %s#%d: %v", ErrUnreadable, f.Repository, f.Number, err)
 	}
-	return applied, write(ctx, ix.Store, key, func(value []byte, found bool) ([]byte, bool, error) {
+	return write(ctx, ix.Store, key, func(value []byte, found bool) ([]byte, bool, error) {
 		var cur *delivery.Candidate
 		if found {
 			c, err := delivery.DecodeCandidate(value)

modules/mesh-delivery-indexer/internal/index/index_test.go

@@ -2,6 +2,7 @@ package index
 
 import (
 	"context"
+	"errors"
 	"strings"
 	"testing"
 
@@ -27,6 +28,15 @@ type memStore struct {
 	writes      int
 	beforeWrite func()
 	failWrite   func(key string) error // a write's own error, asked before each Create and Update
+	maxValue    int                    // the bucket's value cap (buscompose.StateMaxValueBytes); a larger value is refused as the bus refuses it
+}
+
+// tooBig is the bus's refusal of a value over a bucket's cap.
+func (m *memStore) tooBig(value []byte) error {
+	if m.maxValue > 0 && len(value) > m.maxValue {
+		return errors.New("nats: API error: code=400 err_code=10054 description=message size exceeds maximum allowed")
+	}
+	return nil
 }
 
 func newMem() *memStore { return &memStore{vals: map[string][]byte{}, revs: map[string]uint64{}} }
@@ -68,6 +78,9 @@ func (m *memStore) Create(_ context.Context, key string, value []byte) error {
 	if _, ok := m.vals[key]; ok {
 		return ErrConflict
 	}
+	if err := m.tooBig(value); err != nil {
+		return err
+	}
 	m.writes++
 	m.put(key, value)
 	return nil
@@ -82,6 +95,9 @@ func (m *memStore) Update(_ context.Context, key string, value []byte, rev uint6
 	if _, ok := m.vals[key]; !ok || m.revs[key] != rev {
 		return ErrConflict
 	}
+	if err := m.tooBig(value); err != nil {
+		return err
+	}
 	m.writes++
 	m.put(key, value)
 	return nil

modules/mesh-delivery-indexer/internal/index/pending.go

@@ -44,14 +44,32 @@ const NoBuild = "no build: "
 // the message is left unacknowledged, so the bus delivers it again, and nothing is written.
 var ErrOwnBuildUnknown = errors.New("the build of the indexer this program runs is not known")
 
-// Pending is one value of the pending state: the merged message whole, as the forge bridge encoded it, the group it
+// PendingRef is what a pending value keeps of its merged message instead of a copy (a merge of a repository with many
+// modules is about 0.5 MB, over the state's 256 KiB value cap; issue 1585): the small fields the waits are worked out
+// from. The message itself is read from the forge bridge's stream by Pending.Seq when a take-in needs it.
+type PendingRef struct {
+	Repository string `json:"repository"`
+	Number     int    `json:"number,omitempty"`
+	Merge      string `json:"merge"`
+	// Branch is the pull request's branch, which names its candidate: a merge covered by a newer one is taken out of it.
+	Branch  string          `json:"branch,omitempty"`
+	Members []delivery.Head `json:"members,omitempty"`
+	// Holds are the modules the merge's manifests name, which indexer_pending says it holds back.
+	Holds []string `json:"holds,omitempty"`
+}
+
+// Pending is one value of the pending state: a reference to the merged message (Seq, its sequence on the forge bridge's
+// stream, and Ref), or, in a value an earlier indexer wrote, the message whole as the forge bridge encoded it; the group it
 // was merged in (Ended once the group's end was heard), since when it is held, the indexer build its revision waits
 // for (absent while it waits for nothing yet, or behind a group being gathered), the build of the indexer that last
 // wrote it, the wait it was last said under on the take-in stream (Said, SaidAt), and Taking, set by a take-in that
 // claimed it: a second indexer that finds it claimed takes nothing in (ADR 0633 §1: never two take-ins of one merge).
 type Pending struct {
 	V          int             `json:"v"`
-	Forge      json.RawMessage `json:"forge"`
+	Seq        uint64          `json:"seq,omitempty"`
+	Ref        *PendingRef     `json:"ref,omitempty"`
+	Forge      json.RawMessage `json:"forge,omitempty"`
+	Lost       string          `json:"lost,omitempty"`
 	Group      string          `json:"group,omitempty"`
 	Ended      bool            `json:"ended,omitempty"`
 	Since      time.Time       `json:"since"`
@@ -63,12 +81,19 @@ type Pending struct {
 	Taking     string          `json:"taking,omitempty"`
 }
 
-// PendingEntry is one key of the pending state as read: its key, revision, value and the merged message decoded.
+// PendingEntry is one key of the pending state as read: its key, revision, value and the merged message decoded. For a
+// value that keeps a reference, Forge holds only the fields of the reference (Light) until Indexer.load reads the message
+// from the stream; Holds are the modules the merge's manifests name.
 type PendingEntry struct {
 	Key      string
 	Revision uint64
 	Value    Pending
 	Forge    forgemsg.Forge
+	Light    bool
+	Holds    []string
+	// Covered says a newer merge of the same repository is in the same revision: its message is not read or applied, since
+	// applying the newest writes every module whose manifest differs from what is held (modules.go).
+	Covered bool
 }
 
 // DecodePending reads one pending value and its merged message.
@@ -80,6 +105,11 @@ func DecodePending(data []byte) (Pending, forgemsg.Forge, error) {
 	if p.V != 1 {
 		return p, forgemsg.Forge{}, fmt.Errorf("a pending value of version %d, not 1", p.V)
 	}
+	if len(p.Forge) == 0 && p.Ref != nil {
+		r := p.Ref
+		return p, forgemsg.Forge{V: delivery.Version, Kind: forgemsg.ForgeMerged, Repository: r.Repository, Number: r.Number,
+			Merge: r.Merge, Branch: r.Branch, Group: p.Group, Members: r.Members}, nil
+	}
 	f, err := forgemsg.DecodeForge(p.Forge)
 	if err != nil {
 		return p, f, fmt.Errorf("its merged message: %w", err)
@@ -119,11 +149,115 @@ func ReadPending(ctx context.Context, st Store, logf func(string, ...any)) ([]Pe
 			}
 			continue
 		}
-		out = append(out, PendingEntry{Key: key, Revision: rev, Value: p, Forge: f})
+		e := PendingEntry{Key: key, Revision: rev, Value: p, Forge: f, Light: len(p.Forge) == 0}
+		if p.Ref != nil {
+			e.Holds = p.Ref.Holds
+		} else {
+			e.Holds = holdsOf(f)
+		}
+		out = append(out, e)
 	}
 	return out, nil
 }
 
+// holdsOf are the modules a merged message's manifests name, sorted.
+func holdsOf(f forgemsg.Forge) []string {
+	var out []string
+	for _, raw := range f.Manifests {
+		if name := manifestModule(raw); name != "" && !slices.Contains(out, name) {
+			out = append(out, name)
+		}
+	}
+	slices.Sort(out)
+	return out
+}
+
+// refOf is what a pending value keeps of the merged message f (PendingRef).
+func refOf(f forgemsg.Forge) *PendingRef {
+	return &PendingRef{Repository: f.Repository, Number: f.Number, Merge: f.Merge, Branch: f.Branch, Members: f.Members, Holds: holdsOf(f)}
+}
+
+// heldMessage is the message Arrive was handed for a sequence, kept in memory until its merge is taken in or dropped.
+func (ix *Indexer) heldMessage(seq uint64) (forgemsg.Forge, bool) {
+	ix.heldMu.Lock()
+	defer ix.heldMu.Unlock()
+	f, ok := ix.held[seq]
+	return f, ok
+}
+
+func (ix *Indexer) hold(seq uint64, f forgemsg.Forge) {
+	ix.heldMu.Lock()
+	defer ix.heldMu.Unlock()
+	if ix.held == nil {
+		ix.held = map[uint64]forgemsg.Forge{}
+	}
+	ix.held[seq] = f
+}
+
+func (ix *Indexer) forget(entries ...PendingEntry) {
+	ix.heldMu.Lock()
+	defer ix.heldMu.Unlock()
+	for _, e := range entries {
+		delete(ix.held, e.Value.Seq)
+	}
+}
+
+// load gives the entry the merged message whole: the copy an earlier value holds, the message Arrive was handed (kept in
+// memory), else the message read from the forge bridge's stream by the value's sequence. A stream that no longer holds it
+// answers ErrForgeGone, a bus that refuses the read its error; a message that is not the merge the value refers to (a
+// stream rebuilt under the same sequence) is refused.
+func (ix *Indexer) load(ctx context.Context, e PendingEntry) (PendingEntry, error) {
+	if !e.Light {
+		return e, nil
+	}
+	if f, ok := ix.heldMessage(e.Value.Seq); ok {
+		e.Forge, e.Light = f, false
+		return e, nil
+	}
+	if ix.Message == nil {
+		return e, fmt.Errorf("the forge bridge is not asked by this indexer, so %s (%s#%d) cannot be read", e.Key, e.Forge.Repository, e.Forge.Number)
+	}
+	data, err := ix.Message(ctx, e.Forge.Repository, e.Forge.Merge)
+	if err != nil {
+		return e, fmt.Errorf("the forge bridge could not answer for the merge of %s#%d at %s: %w", e.Forge.Repository, e.Forge.Number, e.Forge.Merge, err)
+	}
+	f, err := forgemsg.DecodeForge(data)
+	if err != nil {
+		return e, fmt.Errorf("the forge bridge's answer for %s is not a forge message: %w", e.Key, err)
+	}
+	if f.Kind != forgemsg.ForgeMerged || f.Repository != e.Forge.Repository || f.Merge != e.Forge.Merge {
+		return e, fmt.Errorf("the forge bridge's answer is not the merge %s#%d at %s that %s refers to", e.Forge.Repository, e.Forge.Number, e.Forge.Merge, e.Key)
+	}
+	e.Forge, e.Light = f, false
+	return e, nil
+}
+
+// loadNewest prepares the ready merges of one revision, in merge order. Of the merges of one repository only the newest is
+// loaded: applying it writes every module whose manifest differs from what is held, so it covers the older ones, which are
+// marked Covered and never read. A newest merge the forge bridge cannot give is answered in lost with its reason, by key, and its revision is held (holdLost).
+func (ix *Indexer) loadNewest(ctx context.Context, entries []PendingEntry) (out, lost []PendingEntry, reasons map[string]string) {
+	out = slices.Clone(entries)
+	reasons = map[string]string{}
+	newest := map[string]bool{}
+	for i := len(out) - 1; i >= 0; i-- {
+		repo := strings.ToLower(out[i].Forge.Repository)
+		if newest[repo] {
+			out[i].Covered = true
+			continue
+		}
+		newest[repo] = true
+		full, err := ix.load(ctx, out[i])
+		if err != nil {
+			lost = append(lost, out[i])
+			reasons[out[i].Key] = err.Error()
+			continue
+		}
+		out[i] = full
+	}
+	slices.Reverse(lost)
+	return out, lost, reasons
+}
+
 // Waits is the pending state read as what waits (ADR 0633 §3, §4): Ready are the merges no group still being gathered
 // holds back, in merge order, which are one revision together; Groups are the groups still being gathered, each with
 // its members held so far; Behind are the merges in a gathered group's member repositories that wait behind it, by the
@@ -268,12 +402,9 @@ func (ix *Indexer) Arrive(ctx context.Context, seq uint64, f forgemsg.Forge) (Ap
 	}
 	ix.pendingMu.Lock()
 	defer ix.pendingMu.Unlock()
-	raw, err := forgemsg.EncodeForge(f)
-	if err != nil {
-		return Applied{}, "", fmt.Errorf("%w: %v", ErrUnreadable, err)
-	}
 	key := takein.PendingKey(seq)
-	data, err := encodePending(Pending{Forge: raw, Group: f.Group, Since: ix.now(), LastWriter: own})
+	ix.hold(seq, f)
+	data, err := encodePending(Pending{Seq: seq, Ref: refOf(f), Group: f.Group, Since: ix.now(), LastWriter: own})
 	if err != nil {
 		return Applied{}, "", err
 	}
@@ -461,18 +592,65 @@ func (ix *Indexer) evaluate(ctx context.Context, own string, start bool) (Applie
 			}
 		}
 	}
-	names, dry, err := ix.computeOver(ctx, w.Ready)
+	// Of each repository's merges only the newest is read (from memory, else asked of the forge bridge: a pending value
+	// keeps a reference); the older ones are covered by it. A newest merge that cannot be read is said and
+	// holds its revision: nothing of it is taken in silently.
+	ready, lost, reasons := ix.loadNewest(ctx, w.Ready)
+	if len(lost) > 0 {
+		return Applied{}, ix.waitingLine(w), ix.holdLost(ctx, w.Ready, lost, reasons)
+	}
+	names, dry, err := ix.computeOver(ctx, ready)
 	if err != nil {
 		return Applied{}, "", err
 	}
 	if names == own {
-		a, err := ix.takeInWhole(ctx, w.Ready, own, "")
+		a, err := ix.takeInWhole(ctx, ready, own, "")
 		if errors.Is(err, errClaimLost) {
 			return a, "claimed by another take-in", nil
 		}
 		return a, ix.waitingLine(w), err
 	}
-	return Applied{}, ix.waitingLine(w), ix.holdFor(ctx, w.Ready, names, own, dry)
+	return Applied{}, ix.waitingLine(w), ix.holdFor(ctx, ready, names, own, dry)
+}
+
+// holdLost holds a revision whose newest merge of a repository cannot be read (the forge bridge's stream no longer holds
+// it, or the bus refuses the read): said once on take-in.pending with the lost keys (TakeIn.Lost), and on each lost entry
+// (Pending.Lost, the reason, which indexer_pending shows), until a newer merge of its repository covers it or
+// indexer_drop_pending drops it. Nothing of the revision is taken in meanwhile.
+func (ix *Indexer) holdLost(ctx context.Context, ready, lost []PendingEntry, reasons map[string]string) error {
+	t := revisionWait(takein.TakeInPending, ready, "")
+	for _, g := range lost {
+		t.Lost = append(t.Lost, g.Key)
+	}
+	said := true
+	for _, e := range ready {
+		isLost := slices.Contains(t.Lost, e.Key)
+		if e.Value.Said != t.Key || e.Value.SaidKind != takein.TakeInPending || (isLost && e.Value.Lost == "") {
+			said = false
+		}
+	}
+	if said {
+		return nil
+	}
+	for _, g := range lost {
+		ix.logf("take-in: %s (%s#%d) is not taken in and holds its revision, the forge bridge could not give its message: %s; a newer merge of %s covers it, indexer_drop_pending drops it",
+			g.Key, g.Forge.Repository, g.Forge.Number, reasons[g.Key], g.Forge.Repository)
+	}
+	if !ix.sayTakeIn(ctx, t) {
+		return nil
+	}
+	var kept []PendingEntry
+	for _, e := range ready {
+		if !slices.Contains(t.Lost, e.Key) {
+			kept = append(kept, e)
+		}
+	}
+	for _, g := range lost {
+		reason := reasons[g.Key]
+		ix.markSaid(ctx, []PendingEntry{g}, &t, func(p *Pending) { p.Lost = reason })
+	}
+	ix.markSaid(ctx, kept, &t, nil)
+	return nil
 }
 
 // waitingLine says what waits after an evaluation, for the heard state.
@@ -510,7 +688,7 @@ func (ix *Indexer) dry() *dryRun {
 	d := &dryRun{}
 	x := &Indexer{Manifests: ix.Manifests, Packages: ix.Packages, JudgeID: ix.JudgeID, Files: ix.Files, GoSum: ix.GoSum,
 		GoMod: ix.GoMod, Now: ix.Now, Builds: ix.Builds, Named: ix.Named, Trunk: ix.Trunk, Read: ix.Read, Contains: ix.Contains,
-		ReadOpen: nil, OwnBuild: nil, SayRefused: nil, SayAccepted: nil, SayTakeIn: nil, Pending: nil}
+		ReadOpen: nil, OwnBuild: nil, Message: ix.Message, SayRefused: nil, SayAccepted: nil, SayTakeIn: nil, Pending: nil}
 	x.Logf = func(format string, args ...any) { ix.logf("take-in, computed and not written: "+format, args...) }
 	x.Store, d.candidates = over(ix.Store)
 	x.Modules, d.modules = over(ix.Modules)
@@ -544,6 +722,9 @@ func (ix *Indexer) dry() *dryRun {
 func (ix *Indexer) computeOver(ctx context.Context, ready []PendingEntry) (string, *dryRun, error) {
 	d := ix.dry()
 	for _, e := range ready {
+		if e.Covered {
+			continue
+		}
 		if _, err := d.ix.ApplyMessage(ctx, e.Forge); err != nil {
 			if errors.Is(err, ErrUnreadable) {
 				continue
@@ -646,7 +827,23 @@ func (ix *Indexer) takeInWholeBy(ctx context.Context, entries []PendingEntry, ow
 		return Applied{}, errClaimLost
 	}
 	var applied Applied
+	newest := map[string]PendingEntry{}
 	for _, e := range claimed {
+		if !e.Covered {
+			newest[strings.ToLower(e.Forge.Repository)] = e
+		}
+	}
+	for _, e := range claimed {
+		if e.Covered {
+			by := newest[strings.ToLower(e.Forge.Repository)]
+			ix.logf("take-in: %s (%s#%d) is covered by %s, the newest merge of %s in this revision: its message is not read, and it is ended with it", e.Key, e.Forge.Repository, e.Forge.Number, by.Key, e.Forge.Repository)
+			// Its pull request leaves its group's candidate as a merged message takes it out; nothing else of it is applied.
+			if err := ix.removeCandidate(ctx, e.Forge); err != nil {
+				ix.release(ctx, claimed)
+				return applied, fmt.Errorf("taking %s (%s#%d) out of its candidate: %w", e.Key, e.Forge.Repository, e.Forge.Number, err)
+			}
+			continue
+		}
 		a, err := ix.ApplyMessage(ctx, e.Forge)
 		applied.Written = append(applied.Written, a.Written...)
 		if a.Late != "" {
@@ -666,6 +863,7 @@ func (ix *Indexer) takeInWholeBy(ctx context.Context, entries []PendingEntry, ow
 			ix.logf("take-in: %s.%s is taken in and not removed: %v", PendingState, e.Key, err)
 		}
 	}
+	ix.forget(claimed...)
 	ix.logf("take-in: %d merges taken in as one revision by %s%s, oldest %s", len(claimed), own, byWords(by), claimed[0].Key)
 	for _, t := range saidWaits(claimed) {
 		t.By, t.Why = who, why
@@ -809,11 +1007,14 @@ func waitOf(entries []PendingEntry, what, behind string) takein.PendingWait {
 	}
 	for _, e := range entries {
 		pw.Keys = append(pw.Keys, e.Key)
-		for _, raw := range e.Forge.Manifests {
-			if name := manifestModule(raw); name != "" && !slices.Contains(pw.Holds, name) {
+		for _, name := range e.Holds {
+			if !slices.Contains(pw.Holds, name) {
 				pw.Holds = append(pw.Holds, name)
 			}
 		}
+		if e.Value.Lost != "" {
+			pw.Lost = append(pw.Lost, e.Key)
+		}
 		if e.Value.Said != "" && e.Value.SaidAt.After(pw.SaidAt) {
 			pw.Said, pw.SaidAt = "take-in."+e.Value.SaidKind, e.Value.SaidAt
 		}
@@ -856,6 +1057,11 @@ func (ix *Indexer) TakeInPendingByHand(ctx context.Context, key, by, why string)
 		r.Answer = fmt.Sprintf("nothing waits under %s: indexer_pending names the waits", key)
 		return r
 	}
+	take, lost, reasons := ix.loadNewest(ctx, take)
+	if len(lost) > 0 {
+		r.Answer = fmt.Sprintf("nothing is taken in: the message of %s is not read (%s); a newer merge of its repository covers it, indexer_drop_pending drops it", lost[0].Key, reasons[lost[0].Key])
+		return r
+	}
 	ix.logf("take-in: a hand take-in of %s (%d merges) asked by %s: %s", key, len(take), by, why)
 	hand := fmt.Sprintf("%s (%s)", by, why)
 	if _, err := ix.takeInWholeBy(ctx, take, own, hand, by, why); err != nil {
@@ -897,6 +1103,7 @@ func (ix *Indexer) DropPending(ctx context.Context, key, by, why string) TakenIn
 		r.Answer = fmt.Sprintf("%s.%s is not removed: %v", PendingState, key, err)
 		return r
 	}
+	ix.forget(e)
 	ix.logf("take-in: %s (%s#%d at %s) dropped by hand, asked by %s: %s; nothing of it is taken in", key, e.Forge.Repository, e.Forge.Number, e.Forge.Merge, by, why)
 	if e.Value.Said != "" && e.Value.SaidKind == takein.TakeInPending {
 		var same []PendingEntry
@@ -919,3 +1126,42 @@ func (ix *Indexer) DropPending(ctx context.Context, key, by, why string) TakenIn
 	}
 	return r
 }
+
+// TakeInMerge is the hand take-in of one merge (indexer_take_in_merge, issue 1585): its merged message is asked of the forge
+// bridge and handed to the take-in as a delivered merged message is (Arrive, under the stream sequence seq, which keeps the
+// merge order), so it is held for the indexer its revision names or taken in, and a merge already held under that
+// sequence is not written twice. For a merge the take-in never took in. The bridge's own words answer when it cannot give
+// the message.
+func (ix *Indexer) TakeInMerge(ctx context.Context, repository, merge string, seq uint64, by, why string) TakenIn {
+	r := TakenIn{Module: takein.PendingKey(seq)}
+	if ix.Message == nil {
+		r.Answer = "this indexer does not ask the forge bridge"
+		return r
+	}
+	data, err := ix.Message(ctx, repository, merge)
+	if err != nil {
+		r.Answer = fmt.Sprintf("the forge bridge could not answer for the merge of %s at %s: %v", repository, merge, err)
+		return r
+	}
+	f, err := forgemsg.DecodeForge(data)
+	if err != nil {
+		r.Answer = fmt.Sprintf("the forge bridge's answer for %s at %s is not a forge message: %v", repository, merge, err)
+		return r
+	}
+	if f.Kind != forgemsg.ForgeMerged || f.Merge != merge || f.Repository != repository {
+		r.Answer = fmt.Sprintf("the forge bridge's answer is not the merge of %s at %s", repository, merge)
+		return r
+	}
+	ix.logf("take-in: a hand take-in of the merge %s#%d at %s (sequence %d) asked by %s: %s", f.Repository, f.Number, f.Merge, seq, by, why)
+	a, words, err := ix.Arrive(ctx, seq, f)
+	if err != nil {
+		r.Answer = err.Error()
+		return r
+	}
+	r.Stored, r.Repository, r.Commit = true, f.Repository, f.Merge
+	r.Answer = fmt.Sprintf("%s#%d at %s handed to the take-in as a delivered merge (%d keys written)", f.Repository, f.Number, f.Merge, len(a.Written))
+	if words != "" {
+		r.Answer += "; " + words
+	}
+	return r
+}

modules/mesh-delivery-indexer/internal/index/pending_test.go

@@ -11,6 +11,7 @@ import (
 
 	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-forge-bridge/forgemsg"
 	"git.novox.be/novox/mesh-delivery/modules/mesh-delivery-indexer/takein"
+	"git.novox.be/novox/mesh-sdk/go/buscompose"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/process"
 )
@@ -22,6 +23,7 @@ type takeInBed struct {
 	mods    *memStore
 	pending *memStore
 	said    []takein.TakeIn
+	bridge  map[string][]byte // what the forge bridge answers (bridge_merged_message), by repository@merge
 	base    forgemsg.Forge
 	logs    *strings.Builder
 }
@@ -35,9 +37,16 @@ func newTakeInBed(t *testing.T) *takeInBed {
 	}
 	reportToolchain(t, ix, "mesh-build-go", "novox", "go", "go1.27.1")
 	reportToolchain(t, ix, "mesh-build-go", "ace", "go", "go1.27.1")
-	b := &takeInBed{ix: ix, mods: mods, pending: newMem(), base: f, logs: &strings.Builder{}}
+	b := &takeInBed{ix: ix, mods: mods, pending: newMem(), bridge: map[string][]byte{}, base: f, logs: &strings.Builder{}}
 	ix.Verdicts = newMem()
+	b.pending.maxValue = buscompose.StateMaxValueBytes
 	ix.Pending = b.pending
+	ix.Message = func(_ context.Context, repository, merge string) ([]byte, error) {
+		if data, ok := b.bridge[repository+"@"+merge]; ok {
+			return data, nil
+		}
+		return nil, errors.New("the gate holds no merge of " + repository + " with that commit")
+	}
 	ix.SayTakeIn = func(_ context.Context, t takein.TakeIn) error { b.said = append(b.said, t); return nil }
 	logf := ix.Logf
 	ix.Logf = func(format string, args ...any) {
@@ -85,11 +94,22 @@ func (b *takeInBed) merge(number int, c, avahi, indexer string) forgemsg.Forge {
 
 func (b *takeInBed) arrive(t *testing.T, seq uint64, f forgemsg.Forge) {
 	t.Helper()
+	b.publish(t, f)
 	if _, _, err := b.ix.Arrive(context.Background(), seq, f); err != nil {
 		t.Fatalf("arrive %d: %v", seq, err)
 	}
 }
 
+// publish lets the bed's forge bridge answer the merged message f, as bridge_merged_message does.
+func (b *takeInBed) publish(t *testing.T, f forgemsg.Forge) {
+	t.Helper()
+	data, err := forgemsg.EncodeForge(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+	b.bridge[f.Repository+"@"+f.Merge] = data
+}
+
 func (b *takeInBed) keys() []string {
 	k, _ := b.pending.Keys(context.Background())
 	slices.Sort(k)
@@ -179,7 +199,7 @@ func TestTakeIn(t *testing.T) { // 1585/T3-T13 (ADR 0633)
 		// The new indexer starts; its build is not known at first: a hand ask is answered meanwhile (R5), and the start waits.
 		next := &Indexer{}
 		*next = Indexer{Store: b.ix.Store, Modules: b.ix.Modules, Manifests: b.ix.Manifests, Graph: b.ix.Graph, Verdicts: b.ix.Verdicts,
-			Packages: b.ix.Packages, Builds: b.ix.Builds, Pending: b.pending, SayTakeIn: b.ix.SayTakeIn, Logf: b.ix.Logf, GoSum: b.ix.GoSum}
+			Packages: b.ix.Packages, Builds: b.ix.Builds, Pending: b.pending, Message: b.ix.Message, SayTakeIn: b.ix.SayTakeIn, Logf: b.ix.Logf, GoSum: b.ix.GoSum}
 		next.toolchains = b.ix.toolchains
 		asked := 0
 		next.OwnBuild = func(context.Context) (string, error) {
@@ -333,9 +353,7 @@ func TestTakeIn(t *testing.T) { // 1585/T3-T13 (ADR 0633)
 				t.Fatalf("%s: pending %v, claimed %v: want both pending and no claim left", c.name, b.keys(), got)
 			}
 			// The next take-in, not at a start, is not refused by a claim left behind: it takes both in.
-			if _, _, err := b.ix.Arrive(ctx, 4, b.merge(23, sha('e'), "tree-avahi-5", "tree-indexer-2")); err != nil {
-				t.Fatal(err)
-			}
+			b.arrive(t, 4, b.merge(23, sha('e'), "tree-avahi-5", "tree-indexer-2"))
 			if len(b.keys()) != 0 || b.commit(t, "avahi") != sha('e') {
 				t.Errorf("%s: after: pending %v, avahi at %s: want all taken in", c.name, b.keys(), b.commit(t, "avahi"))
 			}
@@ -354,7 +372,8 @@ func TestTakeIn(t *testing.T) { // 1585/T3-T13 (ADR 0633)
 			key, _ := delivery.ToolchainKey(node, "go")
 			x.PutToolchain("mesh-build-go", key, toolchainValue(t, "go", "go1.27.2", "1"), false)
 		}
-		next, _, err := x.computeOver(ctx, WaitsOf(entries).Ready)
+		ready, _, _ := b.ix.loadNewest(ctx, WaitsOf(entries).Ready)
+		next, _, err := x.computeOver(ctx, ready)
 		if err != nil || next == "" || next == b.said[0].WaitsFor {
 			t.Fatalf("the build under the next toolchain: %q %v (the revision names %s)", next, err, b.said[0].WaitsFor)
 		}
@@ -403,12 +422,105 @@ func TestTakeIn(t *testing.T) { // 1585/T3-T13 (ADR 0633)
 			t.Errorf("hand take-in: pending %v, avahi at %s, said %+v", b.keys(), b.commit(t, "avahi"), b.said)
 		}
 	})
+	t.Run("1585 a merge over the value cap is held by reference, a new indexer with an empty memory takes it in through the forge bridge, and a covered pull request leaves its candidate", func(t *testing.T) {
+		big := func(f forgemsg.Forge) forgemsg.Forge {
+			f.Words = strings.Repeat("x", 300*1024)
+			f.Branch = "feat/g"
+			return f
+		}
+		b := newTakeInBed(t)
+		avahi0 := b.fp(t, "avahi")
+		// The forge bridge is not asked at all while the merges are in memory: a 300 KiB merge, over the bucket's cap whole,
+		// is held by reference and a lone one taken in.
+		bridgeDown := func(context.Context, string, string) ([]byte, error) {
+			return nil, errors.New("the bridge does not answer")
+		}
+		answers := b.ix.Message
+		b.ix.Message = bridgeDown
+		b.arrive(t, 1, big(b.merge(20, sha('b'), "tree-avahi-2", "")))
+		if b.fp(t, "avahi") == avahi0 || b.commit(t, "avahi") != sha('b') || len(b.keys()) != 0 || len(b.ix.held) != 0 {
+			t.Fatalf("a big merge alone: avahi at %s, pending %v, in memory %d: want it taken in and forgotten", b.commit(t, "avahi"), b.keys(), len(b.ix.held))
+		}
+		// Two pull requests of one group are open; both then merge (the indexer changed: held for the new build).
+		for n, head := range map[int]string{21: sha('1'), 22: sha('2')} {
+			if err := b.ix.Apply(ctx, pull(catalogueRepo, n, "feat/g", head, "modules/avahi")); err != nil {
+				t.Fatal(err)
+			}
+		}
+		key, _ := delivery.CandidatesKey("feat/g")
+		if _, _, found, _ := b.ix.Store.Get(ctx, key); !found {
+			t.Fatal("the group has no candidate")
+		}
+		b.arrive(t, 2, big(b.merge(21, sha('c'), "tree-avahi-3", "tree-indexer-2")))
+		b.arrive(t, 3, big(b.merge(22, sha('d'), "tree-avahi-4", "tree-indexer-2")))
+		raw, _, _, _ := b.pending.Get(ctx, takein.PendingKey(2))
+		if len(b.keys()) != 2 || len(raw) > 4096 || b.commit(t, "avahi") != sha('b') {
+			t.Fatalf("a big merge held: pending %v, value %d bytes, avahi at %s: want two small values", b.keys(), len(raw), b.commit(t, "avahi"))
+		}
+		named := b.fp(t, delivery.IndexerModule)
+		// The new indexer starts with nothing in memory and the bridge down: the newest merge is said lost with the bridge's
+		// words (event, state), the older one is covered and not lost, and nothing is taken in.
+		next := &Indexer{Store: b.ix.Store, Modules: b.ix.Modules, Manifests: b.ix.Manifests, Graph: b.ix.Graph, Verdicts: b.ix.Verdicts,
+			Packages: b.ix.Packages, Builds: b.ix.Builds, Pending: b.pending, Message: bridgeDown, SayTakeIn: b.ix.SayTakeIn, Logf: b.ix.Logf,
+			GoSum: b.ix.GoSum, OwnBuild: func(context.Context) (string, error) { return named, nil }}
+		next.toolchains = b.ix.toolchains
+		b.said = nil
+		if _, _, err := next.TakeInAtStart(ctx); err != nil {
+			t.Fatal(err)
+		}
+		waits := PendingWaits(mustReadPending(t, b))
+		if len(b.said) != 1 || !slices.Equal(b.said[0].Lost, []string{takein.PendingKey(3)}) || len(waits) != 1 || !slices.Equal(waits[0].Lost, []string{takein.PendingKey(3)}) || b.commit(t, "avahi") != sha('b') {
+			t.Fatalf("lost: said %+v, waits %+v, avahi at %s: want m.3 lost on the event and in indexer_pending, nothing taken in", b.said, waits, b.commit(t, "avahi"))
+		}
+		if v, _, _, _ := b.pending.Get(ctx, takein.PendingKey(3)); !strings.Contains(string(v), "the bridge does not answer") {
+			t.Errorf("m.3 = %s: want the bridge's words", v)
+		}
+		if err := next.PendingAgain(ctx); err != nil || len(b.said) != 1 {
+			t.Errorf("lost again: err %v, said %v: want it said once", err, b.events())
+		}
+		if r := next.TakeInPendingByHand(ctx, takein.PendingKey(2), "lead@shanks", "try"); r.Stored || b.commit(t, "avahi") != sha('b') {
+			t.Errorf("hand take-in of a lost merge: %+v, avahi at %s: want nothing taken in", r, b.commit(t, "avahi"))
+		}
+		// The bridge answers: the newest merge is read through it, the older one is covered, and the revision is taken in.
+		b.publish(t, b.merge(22, sha('d'), "tree-avahi-4", "tree-indexer-2")) // the answer is the message as published, small here
+		next.Message = answers
+		b.bridge[catalogueRepo+"@"+sha('d')], _ = forgemsg.EncodeForge(big(b.merge(22, sha('d'), "tree-avahi-4", "tree-indexer-2")))
+		b.logs.Reset()
+		if err := next.PendingAgain(ctx); err != nil {
+			t.Fatal(err)
+		}
+		if len(b.keys()) != 0 || b.commit(t, "avahi") != sha('d') || !strings.Contains(b.logs.String(), "is covered by") {
+			t.Fatalf("taken in: pending %v, avahi at %s, journal %q: want both merges taken in, the older covered", b.keys(), b.commit(t, "avahi"), b.logs.String())
+		}
+		if _, _, found, _ := b.ix.Store.Get(ctx, key); found {
+			t.Errorf("the group's candidate stays after both its pull requests merged (the covered one is not taken out)")
+		}
+		// A hand take-in of a merge by its commit asks the bridge and runs the message through Arrive.
+		b.ix.Message = answers
+		b.publish(t, big(b.merge(30, sha('e'), "tree-avahi-6", b.base.Trees["modules/"+delivery.IndexerModule])))
+		if r := b.ix.TakeInMerge(ctx, catalogueRepo, sha('e'), 9, "lead@shanks", "held by the cap"); !r.Stored || b.commit(t, "avahi") != sha('e') {
+			t.Fatalf("merge take-in: %+v, avahi at %s: want it taken in", r, b.commit(t, "avahi"))
+		}
+		if r := b.ix.TakeInMerge(ctx, catalogueRepo, sha('9'), 10, "lead@shanks", "no such"); r.Stored || !strings.Contains(r.Answer, "gate holds no merge") {
+			t.Errorf("merge take-in of a merge the bridge does not know: %+v", r)
+		}
+		// An old value that holds the message whole reads as before.
+		old := b.merge(31, sha('f'), "tree-avahi-7", b.base.Trees["modules/"+delivery.IndexerModule])
+		rawOld, _ := forgemsg.EncodeForge(old)
+		data, _ := encodePending(Pending{Forge: rawOld, Since: b.ix.now(), LastWriter: b.fp(t, delivery.IndexerModule)})
+		if err := b.pending.Create(ctx, takein.PendingKey(11), data); err != nil {
+			t.Fatal(err)
+		}
+		if err := b.ix.PendingAgain(ctx); err != nil || b.commit(t, "avahi") != sha('f') {
+			t.Errorf("an old value with the message whole: err %v, avahi at %s: want it taken in", err, b.commit(t, "avahi"))
+		}
+	})
 	t.Run("the dry run names every field of the indexer", func(t *testing.T) {
 		// dry (pending.go) builds an indexer field by field: a field added to Indexer is named there, or this fails.
 		named := map[string]bool{}
 		for _, f := range []string{"Store", "Modules", "Manifests", "Predefined", "ConfigCandidates", "Taken", "Verdicts", "OldSections",
 			"JudgeID", "SayRefused", "SayAccepted", "Packages", "Graph", "Files", "GoSum", "GoMod", "Now", "Builds", "Named", "Trunk",
-			"Read", "Contains", "Logf", "ReadOpen", "OwnBuild", "Pending", "SayTakeIn"} {
+			"Read", "Contains", "Logf", "ReadOpen", "OwnBuild", "Message", "Pending", "SayTakeIn"} {
 			named[f] = true
 		}
 		ty := reflect.TypeOf(Indexer{})
@@ -419,3 +531,12 @@ func TestTakeIn(t *testing.T) { // 1585/T3-T13 (ADR 0633)
 		}
 	})
 }
+
+func mustReadPending(t *testing.T, b *takeInBed) []PendingEntry {
+	t.Helper()
+	entries, err := ReadPending(context.Background(), b.pending, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return entries
+}

modules/mesh-delivery-indexer/internal/index/pending_tools.go

@@ -27,6 +27,18 @@ func PendingTools(pending Store, ask func(key string, value []byte) (TakeInAsk,
 			return a.Result, nil
 		}
 	}
+	merge := func(args map[string]any) (any, error) {
+		seq, _ := args["sequence"].(float64)
+		key, value, err := NewMergeAsk(str(args, "repository"), str(args, "merge"), uint64(seq), str(args, "why"), stdio.CallerOf(args), now())
+		if err != nil {
+			return nil, err
+		}
+		a, err := ask(key, value)
+		if err != nil {
+			return nil, err
+		}
+		return a.Result, nil
+	}
 	return []stdio.Tool{
 		{Name: PendingTool,
 			Description: "What waits for a take-in (ADR 0633): merges the indexer holds in its pending state instead of taking them in. " +
@@ -34,7 +46,8 @@ func PendingTools(pending Store, ask func(key string, value []byte) (TakeInAsk,
 				"(waits-for): the running indexer wrote only what building and moving that indexer needs, and the new indexer takes " +
 				"it in at its start. A group (what group, key g.<group>) is a delivery group whose members are gathered until the " +
 				"forge bridge says its end; a merge in one of its members' repositories waits behind it (behind). Each names its " +
-				"merges, since when it waits, the modules it holds back (holds) and the last take-in event said of it. Empty waits: " +
+				"merges, since when it waits, the modules it holds back (holds), the merges whose message the forge bridge's stream no " +
+				"longer holds (lost: they are not taken in; indexer_drop_pending drops them) and the last take-in event said of it. Empty waits: " +
 				"every merge is taken in. The watchman raises take-in-waits past 60 minutes for a revision, 30 for a group; " +
 				"indexer_take_in_pending and indexer_drop_pending steer a wait.",
 			Input: map[string]any{"type": "object", "properties": map[string]any{}},
@@ -65,5 +78,17 @@ func PendingTools(pending Store, ask func(key string, value []byte) (TakeInAsk,
 				"key": map[string]any{"type": "string", "description": "the pending merge's key, m.<sequence>, as indexer_pending names its merges' wait"},
 				"why": map[string]any{"type": "string", "description": "why it is dropped, in plain words"}}},
 			Run: hand(true)},
+		{Name: TakeInMergeTool,
+			Description: "Take one merge in by hand (ADR 0633 §5, issue 1585): the indexer asks the forge bridge for the merge's merged message " +
+				"(bridge_merged_message) and runs it through the take-in as a delivered merged message, so it is held for the " +
+				"indexer its revision names or taken in. For a merge the take-in did not take in (indexer_heard names its sequence " +
+				"and why). A hand act: who and why are said in the indexer's journal. The bridge's own words answer when it cannot " +
+				"build the message (the gate holds no such merge, the forge does not answer).",
+			Input: map[string]any{"type": "object", "required": []string{"repository", "merge", "sequence", "why"}, "properties": map[string]any{
+				"repository": map[string]any{"type": "string", "description": "the repository, owner/name"},
+				"merge":      map[string]any{"type": "string", "description": "the merge commit, 40 hex digits"},
+				"sequence":   map[string]any{"type": "integer", "description": "the merge's sequence on the forge bridge's stream, as indexer_heard names it"},
+				"why":        map[string]any{"type": "string", "description": "why it is taken in by hand, in plain words"}}},
+			Run: merge},
 	}
 }

modules/mesh-delivery-indexer/internal/index/takein.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
@@ -36,12 +37,17 @@ type TakeInAsk struct {
 	Digest string `json:"digest,omitempty"`
 	// Pending asks the wait under this take-in key to be taken in by hand (indexer_take_in_pending), or with Drop the
 	// one pending merge under it to be dropped (indexer_drop_pending), instead of a module (pending.go, ADR 0633 §5).
-	Pending  string    `json:"pending,omitempty"`
-	Drop     bool      `json:"drop,omitempty"`
-	By       string    `json:"by,omitempty"`
-	At       time.Time `json:"at"`
-	Result   *TakenIn  `json:"result,omitempty"`
-	Answered time.Time `json:"answered,omitzero"`
+	Pending string `json:"pending,omitempty"`
+	// Merge asks the merge of MergeRepository at this commit to be taken in by hand (indexer_take_in_merge): its merged message
+	// is asked of the forge bridge and run through the take-in as a delivered one, under its stream sequence Sequence.
+	Merge           string    `json:"merge,omitempty"`
+	MergeRepository string    `json:"merge-repository,omitempty"`
+	Sequence        uint64    `json:"sequence,omitempty"`
+	Drop            bool      `json:"drop,omitempty"`
+	By              string    `json:"by,omitempty"`
+	At              time.Time `json:"at"`
+	Result          *TakenIn  `json:"result,omitempty"`
+	Answered        time.Time `json:"answered,omitzero"`
 }
 
 // Done says the ask is answered.
@@ -56,8 +62,8 @@ func DecodeTakeIn(data []byte) (TakeInAsk, error) {
 	if a.V != 1 {
 		return a, fmt.Errorf("a takeins value of version %d, not 1", a.V)
 	}
-	if a.Module == "" && a.Repository == "" && a.Pending == "" {
-		return a, errors.New("a takeins value naming no module, repository or pending wait")
+	if a.Module == "" && a.Repository == "" && a.Pending == "" && a.Merge == "" {
+		return a, errors.New("a takeins value naming no module, repository, pending wait or merge")
 	}
 	return a, nil
 }
@@ -87,6 +93,30 @@ func NewTakeInRepository(repository, why, by string, at time.Time) (string, []by
 	return "repository." + key, data, err
 }
 
+// TakeInMergeTool takes one merge in by hand, its merged message asked of the forge bridge (ADR 0633 §5, issue 1585).
+const TakeInMergeTool = "indexer_take_in_merge"
+
+var sha40 = regexp.MustCompile(`^[0-9a-f]{40}$`)
+
+// NewMergeAsk is the value indexer_take_in_merge writes: its key in takeins, `merge.<commit>`, and the value. sequence is
+// the merge's sequence on the forge bridge's stream, as indexer_heard names it: the pending merge is keyed by it, which
+// keeps the merge order.
+func NewMergeAsk(repository, merge string, sequence uint64, why, by string, at time.Time) (string, []byte, error) {
+	repository, merge = strings.TrimSpace(repository), strings.TrimSpace(merge)
+	switch {
+	case !strings.Contains(repository, "/"):
+		return "", nil, errors.New("name the repository as owner/name (repository)")
+	case !sha40.MatchString(merge):
+		return "", nil, errors.New("name the merge commit, 40 hex digits (merge)")
+	case sequence == 0:
+		return "", nil, errors.New("name the merge's sequence on the forge bridge's stream (sequence), as indexer_heard names it")
+	case strings.TrimSpace(why) == "":
+		return "", nil, errors.New("say why (why): a hand act is said in the journal")
+	}
+	data, err := json.Marshal(TakeInAsk{V: 1, Merge: merge, MergeRepository: repository, Sequence: sequence, Why: strings.TrimSpace(why), By: by, At: at.UTC()})
+	return "merge." + merge, data, err
+}
+
 // NewPendingAsk is the value indexer_take_in_pending (drop false) or indexer_drop_pending (drop true) writes: its key
 // in takeins, `pending.<take-in|drop>.<key>`, and the value. key is a wait's key as indexer_pending names it, for a
 // drop one pending merge's.

modules/mesh-delivery-indexer/manifest_test.go

@@ -129,15 +129,15 @@ func TestManifestDeclarations(t *testing.T) { // 1238/AC1, 1444 (reads the build
 	// Three invokes: the file of a registered module's manifest and lock files (registered.go), the forge's trees (the named paths' objects, since the indexer is the one reader of a manifest's paths:
 	// ADR 0499 clauses 2 and 3, ADR 0495 clause 1; and the module directories of the trunk, issue 1900) and whether a
 	// commit is in another (issue 1900).
-	if want := []string{"gitea.gitea_commit_trees", "gitea.gitea_contains", "gitea.gitea_get_file", "gitea.gitea_open_pulls", "seat:node-engine.composition"}; !reflect.DeepEqual(m.Invokes, want) {
+	if want := []string{"gitea.gitea_commit_trees", "gitea.gitea_contains", "gitea.gitea_get_file", "gitea.gitea_open_pulls", "mesh-delivery-forge-bridge.bridge_merged_message", "seat:node-engine.composition"}; !reflect.DeepEqual(m.Invokes, want) {
 		t.Errorf("invokes = %v, want %v", m.Invokes, want)
 	}
 	// 1945: indexer_take_in, served by its tools bundle through the takeins state; the process serves none. The same bundle
 	// reads the verdicts state (indexer_verdicts) and asks the indexer to judge again through the takeins state
 	// (indexer_judge; issue 774, clause 3). 1966/AC11: indexer_old_sections reads the count of the old sections (state oldsections).
 	// 1585/T12, T13 (ADR 0633 §5): indexer_pending reads the pending state; indexer_take_in_pending and indexer_drop_pending
-	// ask through takeins.
-	if want := []string{"indexer_take_in", "indexer_old_sections", "indexer_verdicts", "indexer_judge", index.PendingTool, index.TakeInPendingTool, index.DropPendingTool}; !reflect.DeepEqual(m.Tools, want) {
+	// ask through takeins; indexer_take_in_merge takes one merge in, its message asked of the forge bridge (issue 1585).
+	if want := []string{"indexer_take_in", "indexer_old_sections", "indexer_verdicts", "indexer_judge", index.PendingTool, index.TakeInPendingTool, index.DropPendingTool, index.TakeInMergeTool}; !reflect.DeepEqual(m.Tools, want) {
 		t.Errorf("tools = %v, want %v", m.Tools, want)
 	}
 	// ADR 0604 §2: it holds the seat mesh-catalog, serving its four verbs from its tools bundle (which stays without a

modules/mesh-delivery-indexer/module.json

@@ -21,7 +21,8 @@
     "indexer_judge",
     "indexer_pending",
     "indexer_take_in_pending",
-    "indexer_drop_pending"
+    "indexer_drop_pending",
+    "indexer_take_in_merge"
   ],
   "consumes": [
     "mesh-build-go.toolchain.reported",
@@ -63,6 +64,7 @@
     "gitea.gitea_contains",
     "gitea.gitea_get_file",
     "gitea.gitea_open_pulls",
+    "mesh-delivery-forge-bridge.bridge_merged_message",
     "seat:node-engine.composition"
   ],
   "own-secrets": {

modules/mesh-delivery-indexer/takein/takein.go

@@ -133,6 +133,9 @@ type TakeIn struct {
 	By       string          `json:"by,omitempty"`
 	Why      string          `json:"why,omitempty"`
 	Dropped  bool            `json:"dropped,omitempty"`
+	// Lost are the keys of merges whose message the forge bridge's stream no longer holds: they are not taken in, and the
+	// revision waits until indexer_drop_pending drops them (issue 1585).
+	Lost []string `json:"lost,omitempty"`
 }
 
 func (t TakeIn) check() error {
@@ -230,6 +233,8 @@ type PendingWait struct {
 	Holds    []string        `json:"holds"`
 	Said     string          `json:"said,omitempty"`
 	SaidAt   time.Time       `json:"said-at,omitzero"`
+	// Lost are the keys of its merges whose message the forge bridge's stream no longer holds (TakeIn.Lost).
+	Lost []string `json:"lost,omitempty"`
 }
 
 // PendingAnswer is indexer_pending's answer: every wait, oldest first, and the pending keys that do not read.