Attribute reader shutdown failures to checks that read content

docs/roadmap/remediation.md

@@ -1,6 +1,6 @@
 # Performance Implementation Remediation
 
-**Status:** Remediation in progress; R1 complete.
+**Status:** Remediation in progress; R1–R2 complete.
 
 **Review baseline:** df064bd, reviewed on 2026-10-09 against the
 [performance target](performance.md) and
@@ -90,6 +90,12 @@ tracking remains internal implementation bookkeeping.
 later selected check that has no applicable files. Verify the earlier reader
 user receives the cleanup cause and the child exit error remains discoverable.
 
+**Completion:** Complete. Internal blob-read bookkeeping now identifies the last
+check that actually used the reader. The extended close-failure fixture preserves
+Go-format attribution when Markdown has no files, including the child exit code
+and stderr. The regression failed before the fix and passes afterward; validation
+race tests and compiled public API and dependency checks passed.
+
 ## R3: Qualify Output Allocation Measurements By Their Workload
 
 **Priority:** Low.

internal/validation/tree.go

@@ -19,6 +19,7 @@ type CandidateTree struct {
 	byPath         map[string]int
 	directories    map[string]struct{}
 	blobReader     *git.BlobReader
+	blobReads      uint64
 	symlinkTargets map[string]string
 	closed         bool
 	closeErr       error
@@ -113,6 +114,7 @@ func (tree *CandidateTree) readBlob(ctx context.Context, entry git.TreeEntry) ([
 		}
 		tree.blobReader = git.NewBlobReader(operationContext, tree.repositoryDir)
 	}
+	tree.blobReads++
 	contents, err := tree.blobReader.Read(ctx, entry.ObjectID)
 	if err != nil {
 		return nil, fmt.Errorf("read committed path %q: %w", entry.Path, err)

internal/validation/tree_lifecycle_test.go

@@ -28,17 +28,29 @@ done
 printf 'batch process failed during cleanup\n' >&2
 exit 23`)
 
-	err := Run(context.Background(), lifecycleRequest(repository, commit))
-	var failure *Failure
-	if !errors.As(err, &failure) || failure.Check != GoFormat {
-		t.Fatalf("Run() error = %v, want cleanup failure attributed to GoFormat", err)
-	}
-	var exitErr *exec.ExitError
-	if !errors.As(failure.Cause, &exitErr) || exitErr.ExitCode() != 23 {
-		t.Fatalf("cleanup cause = %v, want Git child exit code 23", failure.Cause)
-	}
-	if !strings.Contains(failure.Cause.Error(), "batch process failed during cleanup") {
-		t.Fatalf("cleanup cause = %v, want captured Git stderr", failure.Cause)
+	for _, testCase := range []struct {
+		name     string
+		markdown *MarkdownSettings
+	}{
+		{name: "formatting only"},
+		{name: "later Markdown check without files", markdown: &MarkdownSettings{}},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			request := lifecycleRequest(repository, commit)
+			request.Settings.Markdown = testCase.markdown
+			err := Run(context.Background(), request)
+			var failure *Failure
+			if !errors.As(err, &failure) || failure.Check != GoFormat {
+				t.Fatalf("Run() error = %v, want cleanup failure attributed to GoFormat", err)
+			}
+			var exitErr *exec.ExitError
+			if !errors.As(failure.Cause, &exitErr) || exitErr.ExitCode() != 23 {
+				t.Fatalf("cleanup cause = %v, want Git child exit code 23", failure.Cause)
+			}
+			if !strings.Contains(failure.Cause.Error(), "batch process failed during cleanup") {
+				t.Fatalf("cleanup cause = %v, want captured Git stderr", failure.Cause)
+			}
+		})
 	}
 }
 

internal/validation/validation.go

@@ -146,10 +146,13 @@ func Run(ctx context.Context, request Request) (result error) {
 			}
 		}()
 		if request.Settings.GoFormat {
-			lastContentCheck = GoFormat
+			readsBefore := tree.blobReads
 			if err := checkGoFormat(ctx, tree); err != nil {
 				return err
 			}
+			if tree.blobReads != readsBefore {
+				lastContentCheck = GoFormat
+			}
 		}
 		if request.Settings.ModuleDistribution.WorkspaceFiles {
 			if err := checkWorkspaceFiles(tree); err != nil {
@@ -157,10 +160,13 @@ func Run(ctx context.Context, request Request) (result error) {
 			}
 		}
 		if request.Settings.ModuleDistribution.LocalReplacements {
-			lastContentCheck = LocalReplacements
+			readsBefore := tree.blobReads
 			if err := checkLocalReplacements(ctx, tree); err != nil {
 				return err
 			}
+			if tree.blobReads != readsBefore {
+				lastContentCheck = LocalReplacements
+			}
 		}
 		if request.Settings.FileSize != nil {
 			if err := checkFileSize(tree, request.Settings.FileSize); err != nil {
@@ -168,10 +174,13 @@ func Run(ctx context.Context, request Request) (result error) {
 			}
 		}
 		if request.Settings.Markdown != nil {
-			lastContentCheck = MarkdownLinks
+			readsBefore := tree.blobReads
 			if err := checkMarkdownLinks(ctx, tree, request.Settings.Markdown.EnforceCheckoutBoundary, request.Output); err != nil {
 				return err
 			}
+			if tree.blobReads != readsBefore {
+				lastContentCheck = MarkdownLinks
+			}
 		}
 	}
 	return nil