Fix report issue upload attachment size check (#8814)

* Fix report issue uploads when attachment size metadata is stale

* code review updates

Author: atavism

lantern-core/utils/reportissue/attachments.go

@@ -36,10 +36,11 @@ var attachmentTypesByExtension = map[string]string{
 }
 
 type AttachmentMetadata struct {
-	Name      string `json:"name"`
-	Path      string `json:"path"`
-	MimeType  string `json:"mimeType"`
-	SizeBytes int64  `json:"sizeBytes"`
+	Name     string `json:"name"`
+	Path     string `json:"path"`
+	MimeType string `json:"mimeType"`
+	// Client-provided size is a stale-prone hint; validate current file size instead.
+	SizeBytes int64 `json:"sizeBytes"`
 }
 
 // LoadAttachments decodes, validates, and reads screenshot attachments for issue reports.
@@ -118,9 +119,6 @@ func prepareAttachment(attachment AttachmentMetadata) (preparedAttachment, error
 	if path == "" {
 		return preparedAttachment{}, fmt.Errorf("attachment %q path is required", name)
 	}
-	if attachment.SizeBytes < 0 {
-		return preparedAttachment{}, fmt.Errorf("attachment %q size must be non-negative", name)
-	}
 
 	attachmentType := resolveDeclaredAttachmentType(attachment.MimeType, name)
 	if !isAllowedAttachmentType(attachmentType) {
@@ -134,8 +132,8 @@ func prepareAttachment(attachment AttachmentMetadata) (preparedAttachment, error
 	if info.IsDir() {
 		return preparedAttachment{}, fmt.Errorf("attachment %q must be a file", name)
 	}
-	if info.Size() != attachment.SizeBytes {
-		return preparedAttachment{}, fmt.Errorf("attachment %q changed on disk before upload", name)
+	if info.Size() == 0 {
+		return preparedAttachment{}, fmt.Errorf("attachment %q must not be empty", name)
 	}
 
 	return preparedAttachment{

lantern-core/utils/reportissue/attachments_test.go

@@ -92,28 +92,41 @@ func TestBuildAttachmentReadsHEICData(t *testing.T) {
 	}
 }
 
-func TestBuildAttachmentRejectsChangedFiles(t *testing.T) {
+func TestBuildAttachmentAllowsCachedSizeMismatch(t *testing.T) {
 	tmpDir := t.TempDir()
 	path := filepath.Join(tmpDir, "vpn_error.png")
-	if err := os.WriteFile(path, testPNGData, 0o644); err != nil {
+	data := append([]byte{}, testPNGData...)
+	data = append(data, 0x00, 0x01, 0x02)
+	if err := os.WriteFile(path, data, 0o644); err != nil {
 		t.Fatalf("write test attachment: %v", err)
 	}
 
-	_, err := validateMetadata([]AttachmentMetadata{{
+	raw, err := json.Marshal([]AttachmentMetadata{{
 		Name:      "vpn_error.png",
 		Path:      path,
 		MimeType:  "image/png",
-		SizeBytes: 999,
+		SizeBytes: -1,
 	}})
-	if err == nil {
-		t.Fatalf("expected size mismatch to fail")
+	if err != nil {
+		t.Fatalf("marshal attachments: %v", err)
+	}
+
+	attachments, err := LoadAttachments(string(raw))
+	if err != nil {
+		t.Fatalf("LoadAttachments returned error: %v", err)
+	}
+	if len(attachments) != 1 {
+		t.Fatalf("expected 1 attachment, got %d", len(attachments))
+	}
+	if string(attachments[0].Data) != string(data) {
+		t.Fatalf("attachment data mismatch: got %q want %q", string(attachments[0].Data), string(data))
 	}
 }
 
-func TestBuildAttachmentRejectsZeroSizeBypass(t *testing.T) {
+func TestBuildAttachmentRejectsEmptyFiles(t *testing.T) {
 	tmpDir := t.TempDir()
 	path := filepath.Join(tmpDir, "vpn_error.png")
-	if err := os.WriteFile(path, testPNGData, 0o644); err != nil {
+	if err := os.WriteFile(path, nil, 0o644); err != nil {
 		t.Fatalf("write test attachment: %v", err)
 	}
 
@@ -123,8 +136,8 @@ func TestBuildAttachmentRejectsZeroSizeBypass(t *testing.T) {
 		MimeType:  "image/png",
 		SizeBytes: 0,
 	}})
-	if err == nil {
-		t.Fatalf("expected missing exact size to fail")
+	if err == nil || !strings.Contains(err.Error(), "must not be empty") {
+		t.Fatalf("expected empty attachment error, got %v", err)
 	}
 }
 
@@ -169,7 +182,7 @@ func TestLoadAttachmentsRejectsTotalSizeOverLimit(t *testing.T) {
 		Name:      "huge.png",
 		Path:      path,
 		MimeType:  "image/png",
-		SizeBytes: maxAttachmentBytes + 1,
+		SizeBytes: int64(len(testPNGData)),
 	}})
 	if err != nil {
 		t.Fatalf("marshal attachments: %v", err)