A merged message of the catalogue carries its placement files, so the indexer reads placement at the merge without asking the forge again (issue 1126, ADR 0549 §2)

go/delivery/forge_inputs_test.go

@@ -9,9 +9,10 @@ const oddManifest = "{\n\t\"module\":   \"a\",\n  \"z\": 1, \"a\": [ \"x\",\"y\"
 
 func mergedWithInputs() Forge {
 	return Forge{Kind: ForgeMerged, Repository: "novox/mesh-sdk", Number: 36, Head: "aaaa", Merge: "cccc", Root: "t0",
-		Trees:     map[string]string{"a": "t1", "b": "t2"},
-		Manifests: map[string]string{"a": oddManifest},
-		Locks:     map[string]map[string]string{"a": {"go.sum": strings.Repeat("ab", 32)}}}
+		Trees:      map[string]string{"a": "t1", "b": "t2"},
+		Manifests:  map[string]string{"a": oddManifest},
+		Locks:      map[string]map[string]string{"a": {"go.sum": strings.Repeat("ab", 32)}},
+		Placements: map[string]string{"ace": `{"v":1,"node":"ace","modules":[]}`}, PlacementsRead: true}
 }
 
 // 1442/AC1
@@ -21,7 +22,7 @@ func TestForgeMergedCarriesManifestsAndLocks(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	for _, frag := range []string{`"manifests":{"a":`, `"locks":{"a":{"go.sum":`} {
+	for _, frag := range []string{`"manifests":{"a":`, `"locks":{"a":{"go.sum":`, `"placements":{"ace":`, `"placements-read":true`} {
 		if !strings.Contains(string(data), frag) {
 			t.Errorf("the encoding lacks %s: %s", frag, data)
 		}
@@ -47,6 +48,9 @@ func TestForgeMergedRefusesBadInputs(t *testing.T) {
 		"locks outside trees":    {func(f *Forge) { f.Locks["yy"] = map[string]string{"go.sum": "h"} }, `"yy"`},
 		"empty manifest":         {func(f *Forge) { f.Manifests["b"] = "" }, `"b"`},
 		"empty lock hash":        {func(f *Forge) { f.Locks["a"]["go.sum"] = "" }, `"a"`},
+		"placements unsaid":      {func(f *Forge) { f.PlacementsRead = false }, "placements-read"},
+		"placement of no node":   {func(f *Forge) { f.Placements["a.b"] = "{}" }, "names no node"},
+		"placements on a pull":   {func(f *Forge) { f.Kind, f.Action, f.Merge, f.Root, f.Trees = ForgePull, PullOpened, "", "", nil }, "only a merged message"},
 	} {
 		f := mergedWithInputs()
 		tc.mut(&f)

go/delivery/source.go

@@ -537,6 +537,11 @@ type Forge struct {
 	Act   string                       `json:"act,omitempty"`
 	Words string                       `json:"words,omitempty"`
 	Open  []OpenPull                   `json:"open,omitempty"`
+	// Placements are, on a merged message of the catalogue repository, every placement file of the merge commit, the
+	// bytes exact, by node (PlacementFile; novox/hq ADR 0549 §2), and PlacementsRead says they were read, so a catalogue
+	// whose last placement file was removed is told from a message that read none (older writers, another repository).
+	Placements     map[string]string `json:"placements,omitempty"`
+	PlacementsRead bool              `json:"placements-read,omitempty"`
 }
 
 func (f Forge) check() error {
@@ -549,6 +554,17 @@ func (f Forge) check() error {
 	if len(f.Open) > 0 {
 		return fmt.Errorf("delivery: only an open message names open pull requests")
 	}
+	if (len(f.Placements) > 0 || f.PlacementsRead) && f.Kind != ForgeMerged {
+		return fmt.Errorf("delivery: only a merged message carries placement files")
+	}
+	if len(f.Placements) > 0 && !f.PlacementsRead {
+		return fmt.Errorf("delivery: a message with placement files must say it read them (placements-read)")
+	}
+	for node := range f.Placements {
+		if err := checkName("node", node); err != nil {
+			return fmt.Errorf("delivery: a placement file names no node: %w", err)
+		}
+	}
 	if err := checkRepository(f.Repository); err != nil {
 		return err
 	}