Fix download: serve file manually to avoid http.ServeFile header conflicts

main.go

@@ -277,36 +277,40 @@ func servePDF(w http.ResponseWriter, r *http.Request) {
 	hash := chi.URLParam(r, "hash")
 	download := r.URL.Query().Get("download") == "1"
 
-	// Try PDF first, then TXT
+	// Try PDF first, then TXT, then bare
-	for _, ext := range []string{".pdf", ".txt"} {
+	for _, ext := range []string{".pdf", ".txt", ""} {
 		path := filepath.Join(storeDir, hash+ext)
-		if _, err := os.Stat(path); err == nil {
+		fi, err := os.Stat(path)
-			if ext == ".pdf" {
+		if err != nil {
-				w.Header().Set("Content-Type", "application/pdf")
+			continue
-			} else {
-				w.Header().Set("Content-Type", "text/plain")
-			}
-			if download {
-				filename := hash + ext
-				if doc, err := GetDocument(hash); err == nil && doc.Title != "" {
-					filename = sanitizeFilename(doc.Title) + ext
-				}
-				w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, filename))
-			}
-			http.ServeFile(w, r, path)
-			return
 		}
-	}
 
-	// Try without extension
-	path := filepath.Join(storeDir, hash)
-	if _, err := os.Stat(path); err == nil {
 		if download {
-			filename := hash
+			filename := hash + ext
 			if doc, err := GetDocument(hash); err == nil && doc.Title != "" {
 				filename = sanitizeFilename(doc.Title)
+				if ext != "" && !strings.HasSuffix(strings.ToLower(filename), ext) {
+					filename += ext
+				}
 			}
+			f, err := os.Open(path)
+			if err != nil {
+				http.Error(w, "Cannot read file", http.StatusInternalServerError)
+				return
+			}
+			defer f.Close()
+			w.Header().Set("Content-Type", "application/octet-stream")
 			w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, filename))
+			w.Header().Set("Content-Length", fmt.Sprintf("%d", fi.Size()))
+			io.Copy(w, f)
+			return
+		}
+
+		// Inline viewing
+		if ext == ".pdf" || ext == "" {
+			w.Header().Set("Content-Type", "application/pdf")
+		} else {
+			w.Header().Set("Content-Type", "text/plain")
 		}
 		http.ServeFile(w, r, path)
 		return