Say a deleted module's reason, read a context's reason at the merged branch, and keep the snapshot's bytes (hq ADR 0267, review)

cmd/mesh-controller/facts.go

@@ -414,7 +414,9 @@ func gatherFacts(ctx context.Context, open *stores, busVersion string) (snapshot
 			// The module's own build source is said apart: a gate that predates it would read an own
 			// entry among Reads as a context of its own repository.
 			if r.Own {
-				mod.Sources = append(mod.Sources, snapshot.BuildSource{Own: true, Paths: r.Paths})
+				if len(r.Paths) > 0 {
+					mod.Sources = append(mod.Sources, snapshot.BuildSource{Own: true, Paths: r.Paths})
+				}
 				continue
 			}
 			mod.Reads = append(mod.Reads, snapshot.RepositoryName(r.Repository))

cmd/mesh-controller/planner_rules_test.go

@@ -664,6 +664,12 @@ func TestAPlanSaysWhyEachModuleIsInIt(t *testing.T) {
 			"read whole: no build source recorded, so every file of its repository is its build source"},
 		{"nothing recorded, in its directory", gitea, nil, merge("mesh-catalog", "modules/gitea/index.ts"),
 			"read whole: no build source recorded, so its directory is its build source; e.g. modules/gitea/index.ts"},
+		{"a root manifest is not in a module's directory", gitea, nil, merge("mesh-catalog", "module.json", "modules/gitea/x.ts"),
+			"read whole: no build source recorded, so its directory is its build source; e.g. modules/gitea/x.ts"},
+		{"a context on another branch says nothing of this one", agent, map[string][]inventory.ReadRepository{"build-agent": {
+			{Repository: "novox/mesh-controller", Ref: "release", Paths: []string{"internal/link/"}},
+			{Repository: "novox/mesh-controller", Ref: "main"}}}, merge("mesh-controller", "internal/link/handacts.go"),
+			"read whole: no build source recorded, so every file of novox/mesh-controller, which its build context is, is its build source"},
 		{"files not all said", controller, read, link.SourceMoved{Owner: "novox", Repo: "mesh-controller", PathsTruncated: true,
 			Paths: []string{"x"}}, "read whole: the merge's changed files were not all said"},
 	} {

cmd/mesh-controller/release_plan.go

@@ -1567,6 +1567,7 @@ func planWhatIf(ctx context.Context, inv *inventory.Inventory, repository string
 		return err
 	}
 	var from, packaging []inventory.Entry
+	deleted := map[string]bool{}
 	named := map[string]bool{}
 	for _, name := range modules {
 		named[name] = true
@@ -1576,6 +1577,9 @@ func planWhatIf(ctx context.Context, inv *inventory.Inventory, repository string
 		// request's check ask it (novox/hq ADR 0238).
 		r := reachOfMerge(m, entries, read, nil)
 		from, packaging = append(append([]inventory.Entry{}, r.Touched...), r.Deleted...), r.Packaging
+		for _, e := range r.Deleted {
+			deleted[e.Manifest.Module] = true
+		}
 	} else {
 		for _, e := range entries {
 			switch {
@@ -1609,6 +1613,9 @@ func planWhatIf(ctx context.Context, inv *inventory.Inventory, repository string
 	if len(named) == 0 {
 		for _, e := range from {
 			why[e.Manifest.Module] = whyMoved(e, read[e.Manifest.Module], m)
+			if deleted[e.Manifest.Module] {
+				why[e.Manifest.Module] = "its manifest is removed: deleted at its source, forgotten where nothing holds it, not built"
+			}
 		}
 	}
 	rolls := map[string]string{}

cmd/mesh-controller/upgrades.go

@@ -633,14 +633,14 @@ func whyMoved(e inventory.Entry, read []inventory.ReadRepository, m link.SourceM
 			return "read whole: " + whole + ", so every file of its repository is its build source"
 		}
 		for _, p := range m.Paths {
-			if p == moduleManifestFile || inside(p, dir) {
+			if inside(p, dir) {
 				return "read whole: " + whole + ", so its directory is its build source; e.g. " + p
 			}
 		}
 		return "read whole: " + whole
 	}
 	for _, r := range read {
-		if r.Own || !sameRepository(r.Repository, m) {
+		if r.Own || !sameRepository(r.Repository, m) || (r.Ref != "" && r.Ref != m.Base) {
 			continue
 		}
 		if len(r.Paths) > 0 {