fix download route sending headers too early, improve when file not found on download, other minor related changes

src/api/helpers/HandleFileNotFound.go

@@ -23,7 +23,7 @@ func HandleFileNotFound(relPath string, fullPath string, w http.ResponseWriter)
 	//info, err := os.Lstat(fullPath)
 	//if err != nil {
 	//	log.Errorf("HELPERS:HandleFileNotFound - os.Lstat failed: %s", err)
-	//	Return500Msg(w)
+	//	Return500(w)
 	//	return nil
 	//}
 	//if !config.FollowSymlinks && info.Mode()&os.ModeSymlink > 0 {
@@ -35,14 +35,14 @@ func HandleFileNotFound(relPath string, fullPath string, w http.ResponseWriter)
 	start := time.Now()
 	item, err := dc.CrawlNoRecursion(fullPath, nil)
 	if err == nil && (os.IsNotExist(err) || item == nil) {
-		ReturnFake404Msg("path not found", w)
+		ReturnFake404Msg("file not found", w)
 		return nil
 	} else if err != nil {
 		if os.IsNotExist(err) {
-			ReturnFake404Msg("path not found", w)
+			ReturnFake404Msg("file not found", w)
 		} else {
 			log.Errorf("HELPERS:HandleFileNotFound:Crawl - Crawl failed: %s", err)
-			Return500Msg(w)
+			Return500(w)
 		}
 		return nil
 	}
@@ -51,7 +51,7 @@ func HandleFileNotFound(relPath string, fullPath string, w http.ResponseWriter)
 	item, found := sharedcache.Cache.Get(relPath)
 	if !found {
 		// Assume that it doesn't exist.
-		ReturnFake404Msg("path not found", w)
+		ReturnFake404Msg("file not found", w)
 		return nil
 	}
 

src/api/helpers/responseCodes.go

@@ -32,10 +32,14 @@ func HandleRejectDuringInitialCrawl(w http.ResponseWriter) {
 	WriteErrorResponse(http.StatusServiceUnavailable, http.StatusServiceUnavailable, "initial file system crawl in progress", w)
 }
 
-func Return500Msg(w http.ResponseWriter) {
+func Return500(w http.ResponseWriter) {
 	WriteErrorResponse(http.StatusInternalServerError, http.StatusInternalServerError, "internal server error", w)
 }
 
+func Return500Msg(msg string, w http.ResponseWriter) {
+	WriteErrorResponse(500, http.StatusInternalServerError, msg, w)
+}
+
 func Return403Msg(msg string, w http.ResponseWriter) {
 	WriteErrorResponse(http.StatusForbidden, http.StatusForbidden, msg, w)
 }

src/api/helpers/zipstream.go

@@ -66,20 +66,20 @@ func ZipHandlerCompressMultiple(paths []string, w http.ResponseWriter, r *http.R
 		if !item.IsDir {
 			writer, err := zipWriter.Create(relPath)
 			if err != nil {
-				Return500Msg(w)
+				Return500(w)
 				return
 			}
 
 			file, err := os.Open(fullPath)
 			if err != nil {
-				Return500Msg(w)
+				Return500(w)
 				return
 			}
 			defer file.Close()
 
 			_, err = io.Copy(writer, file)
 			if err != nil {
-				Return500Msg(w)
+				Return500(w)
 				return
 			}
 		} else {

src/api/routes/Search.go

@@ -79,7 +79,7 @@ func APISearch(w http.ResponseWriter, r *http.Request) {
 		resp, err := elastic.SimpleQuery(queryString, excludeElements, queryFields)
 		if err != nil {
 			log.Errorf(`ROUTES:Search - Failed to perform Elasticsearch query "%s" - %s`, queryString, err)
-			helpers.Return500Msg(w)
+			helpers.Return500(w)
 			return
 		}
 
@@ -88,7 +88,7 @@ func APISearch(w http.ResponseWriter, r *http.Request) {
 		err = json.NewDecoder(resp.Body).Decode(&respData)
 		if err != nil {
 			log.Errorf(`ROUTES:Search - Failed to parse Elasticsearch response for query "%s" - %s`, queryString, err)
-			helpers.Return500Msg(w)
+			helpers.Return500(w)
 			return
 		}
 

src/api/routes/file/Download.go

@@ -82,6 +82,24 @@ func APIDownload(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if !item.IsDir {
+		var err error
+		// Open the file
+		openFile, err := os.Open(fullPath)
+		if err != nil {
+			if os.IsNotExist(err) {
+				sharedcache.Cache.Remove(relPath) // Remove item from the cache
+				helpers.ReturnFake404Msg("cache out of date, file missing from disk", w)
+			} else {
+				log.Errorf(`Failed to open file for download: "%s" - "%s"`, fullPath, err)
+				helpers.Return500Msg("internal server error accessing file", w)
+			}
+			return
+		}
+		defer openFile.Close()
+
+		// =============================================================================================================
+		// Get the file info
+
 		// Only files can have inline disposition, zip archives cannot
 		// https://stackoverflow.com/a/57994289
 		contentDownload := r.URL.Query().Get("download")
@@ -95,27 +113,24 @@ func APIDownload(w http.ResponseWriter, r *http.Request) {
 
 		// Get the MIME type of the file
 		var mimeType string
-		var err error
+		if item.MimeType == nil { // Only if the MIME type of this item has not been set yet
-		if item.MimeType == nil { // only if the MIME type of this item has not been set yet
 			_, mimeType, _, err = file.GetMimeType(fullPath, true)
 			if err != nil {
 				log.Errorf("ROUTES:Download - Error detecting MIME type: %v", err)
 			} else if mimeType != "" {
 				// GetMimeType() returns an empty string if it was a directory.
-				// Update the cacheitem's MIME in the sharedCache.
 				item.MimeType = &mimeType
-				sharedcache.Cache.Add(relPath, item)
+				sharedcache.Cache.Add(relPath, item) // Update the cacheitem's MIME in the sharedCache.
 			} else {
 				log.Errorf("ROUTES:Download - Failed to match a condition when checking a file's MIME - %s", fullPath)
-				helpers.Return500Msg(w)
+				helpers.Return500(w)
 			}
 		} else {
 			mimeType = *item.MimeType
 		}
 
 		// Get the encoding of this file
-		var encoding string
+		encoding := "utf-8"                               // fall back to utf-8
-		encoding = "utf-8"                                // fall back to utf-8
 		if item.Encoding == nil || *item.Encoding == "" { // only if the encoding of this item has not been set yet
 			encoding, err = file.DetectFileEncoding(fullPath)
 			if err != nil {
@@ -128,6 +143,11 @@ func APIDownload(w http.ResponseWriter, r *http.Request) {
 			encoding = *item.Encoding
 		}
 
+		// =============================================================================================================
+		// Send the file to the client.
+		// We are using `http.ServeContent()` since this allows us to catch and handle any missing files. `http.ServeFile()` returns
+		// the default 404 page if the file is missing from the disk.
+
 		if config.GetConfig().HTTPNoMimeSniffHeader {
 			w.Header().Set("X-Content-Type-Options", "nosniff")
 			mimeType = file.CastTextMimes(mimeType)
@@ -138,32 +158,18 @@ func APIDownload(w http.ResponseWriter, r *http.Request) {
 			w.Header().Set("Content-Type", mimeType+"; charset="+encoding)
 		}
 
-		// =============================================================================================================
-		// Send the file to the client.
-		// We are using `http.ServeContent()` since this allows us to catch and handle any missing files. `http.ServeFile()` returns
-		// the default 404 page if the file is missing from the disk.
-
-		// Open the file
-		openFile, err := os.Open(fullPath)
-		if err != nil {
-			sharedcache.Cache.Remove(relPath) // remove it from the cache
-			helpers.ReturnFake404Msg("file missing from disk, cache out of date", w)
-			return
-		}
-		defer openFile.Close()
-
 		// Get the file info
 		fileInfo, err := openFile.Stat()
 		if err != nil {
 			log.Errorf(`ROUTES:Download - Failed to stat file "%s" - %s`, fullPath, err)
-			helpers.Return500Msg(w)
+			helpers.Return500(w)
 			return
 		}
 
-		// If the file exists, serve it
+		// If the file exists, serve it.
 		http.ServeContent(w, r, fileInfo.Name(), fileInfo.ModTime(), openFile)
 	} else {
-		// Stream archive of the directory here
+		// Stream archive of the directory.
 		w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s.zip"`, item.Name))
 		helpers.ZipHandlerCompress(fullPath, w, r)
 	}

src/api/routes/file/List.go

@@ -72,7 +72,7 @@ func APIList(w http.ResponseWriter, r *http.Request) {
 				fileExists, mimeType, ext, err := file.GetMimeType(fullPath, true)
 				if err != nil {
 					log.Warnf("ROUTES:List - Error detecting MIME type: %v", err)
-					helpers.Return500Msg(w)
+					helpers.Return500(w)
 					return
 				}
 				if !fileExists {

src/api/routes/file/Thumbnail.go

@@ -94,7 +94,7 @@ func APIThumbnail(w http.ResponseWriter, r *http.Request) {
 	}
 	if err != nil {
 		log.Warnf(`ROUTES:Thumb - Error detecting MIME type for "%s". %v`, fullPath, err)
-		helpers.Return500Msg(w)
+		helpers.Return500(w)
 		return
 	}
 	// Update the item's MIME in the cache.
@@ -112,7 +112,7 @@ func APIThumbnail(w http.ResponseWriter, r *http.Request) {
 	imageBytes, err := file.ConvertToPNG(fullPath, mimeType)
 	if err != nil {
 		log.Warnf(`ROUTES:Thumb - Error converting "%s". %v`, fullPath, err)
-		helpers.Return500Msg(w)
+		helpers.Return500(w)
 		return
 	}
 
@@ -121,7 +121,7 @@ func APIThumbnail(w http.ResponseWriter, r *http.Request) {
 	img, err = png.Decode(bytes.NewReader(imageBytes))
 	if err != nil {
 		log.Warnf(`ROUTES:Thumb - Error decoding "%s". %v`, fullPath, err)
-		helpers.Return500Msg(w)
+		helpers.Return500(w)
 		return
 	}
 
@@ -129,14 +129,14 @@ func APIThumbnail(w http.ResponseWriter, r *http.Request) {
 	img, err = resizeImage(img, width, height, square, autoScale)
 	if err != nil {
 		log.Warnf(`ROUTES:Thumb - Error resizing "%s". %v`, fullPath, err)
-		helpers.Return500Msg(w)
+		helpers.Return500(w)
 		return
 	}
 
 	buf, err := file.CompressPNGFile(img, pngQuality)
 	if err != nil {
 		log.Warnf(`ROUTES:Thumb - Error compressing "%s". %v`, fullPath, err)
-		helpers.Return500Msg(w)
+		helpers.Return500(w)
 		return
 	}