MM-38982: fixes SVG uploading (#20141)

* MM-38982: fixes SVG uploading

Uploading SVG files was "almost" treated like an image in some places,
resulting in not showing the SVG on the client.
This is happening because when we fail to generate a mini preview for an
image, we prepend "invalid-" to the MimeType.

This commit adds a check to guard against SVG files in methods that make
no sense for SVGs.

* Reverts invalid-{mimetype} fix

* Uses fileInfo.IsSvg() where it can

app/file.go

@@ -249,7 +249,7 @@ func (a *App) getInfoForFilename(post *model.Post, teamID, channelID, userID, ol
 	info.UpdateAt = post.UpdateAt
 	info.Path = path
 
-	if info.IsImage() {
+	if info.IsImage() && !info.IsSvg() {
 		nameWithoutExtension := name[:strings.LastIndex(name, ".")]
 		info.PreviewPath = pathPrefix + nameWithoutExtension + "_preview.jpg"
 		info.ThumbnailPath = pathPrefix + nameWithoutExtension + "_thumb.jpg"
@@ -752,7 +752,7 @@ func (a *App) UploadFileX(c *request.Context, channelID, name string, input io.R
 
 func (t *UploadFileTask) preprocessImage() *model.AppError {
 	// If SVG, attempt to extract dimensions and then return
-	if t.fileinfo.MimeType == "image/svg+xml" {
+	if t.fileinfo.IsSvg() {
 		svgInfo, err := imaging.ParseSVG(t.teeInput)
 		if err != nil {
 			mlog.Warn("Failed to parse SVG", mlog.Err(err))
@@ -809,7 +809,7 @@ func (t *UploadFileTask) preprocessImage() *model.AppError {
 
 func (t *UploadFileTask) postprocessImage(file io.Reader) {
 	// don't try to process SVG files
-	if t.fileinfo.MimeType == "image/svg+xml" {
+	if t.fileinfo.IsSvg() {
 		return
 	}
 
@@ -937,7 +937,7 @@ func (a *App) DoUploadFileExpectModification(c *request.Context, now time.Time,
 	pathPrefix := now.Format("20060102") + "/teams/" + teamID + "/channels/" + channelID + "/users/" + userID + "/" + info.Id + "/"
 	info.Path = pathPrefix + filename
 
-	if info.IsImage() {
+	if info.IsImage() && !info.IsSvg() {
 		if limitErr := checkImageResolutionLimit(info.Width, info.Height, *a.Config().FileSettings.MaxImageResolution); limitErr != nil {
 			err := model.NewAppError("uploadFile", "api.file.upload_file.large_image.app_error", map[string]interface{}{"Filename": filename}, limitErr.Error(), http.StatusBadRequest)
 			return nil, data, err
@@ -1081,7 +1081,7 @@ func (a *App) generatePreviewImage(img image.Image, previewPath string) {
 // generateMiniPreview updates mini preview if needed
 // will save fileinfo with the preview added
 func (a *App) generateMiniPreview(fi *model.FileInfo) {
-	if fi.IsImage() && fi.MiniPreview == nil {
+	if fi.IsImage() && !fi.IsSvg() && fi.MiniPreview == nil {
 		file, appErr := a.FileReader(fi.Path)
 		if appErr != nil {
 			mlog.Debug("error reading image file", mlog.Err(appErr))
@@ -1093,15 +1093,6 @@ func (a *App) generateMiniPreview(fi *model.FileInfo) {
 			mlog.Debug("generateMiniPreview: prepareImage failed", mlog.Err(err),
 				mlog.String("fileinfo_id", fi.Id), mlog.String("channel_id", fi.ChannelId),
 				mlog.String("creator_id", fi.CreatorId))
-
-			// Since this file is not a valid image (for whatever reason), prevent this fileInfo
-			// from entering generateMiniPreview in the future
-			fi.UpdateAt = model.GetMillis()
-			fi.MimeType = "invalid-" + fi.MimeType
-			if _, err = a.Srv().Store.FileInfo().Upsert(fi); err != nil {
-				mlog.Debug("Invalidating FileInfo failed", mlog.Err(err))
-			}
-
 			return
 		}
 		defer release()

app/import_functions.go

@@ -1233,7 +1233,7 @@ func (a *App) importAttachment(c *request.Context, data *AttachmentImportData, p
 		return nil, appErr
 	}
 
-	if fileInfo.IsImage() {
+	if fileInfo.IsImage() && !fileInfo.IsSvg() {
 		a.HandleImages([]string{fileInfo.PreviewPath}, []string{fileInfo.ThumbnailPath}, [][]byte{fileData})
 	}
 

app/upload.go

@@ -263,7 +263,7 @@ func (a *App) UploadData(c *request.Context, us *model.UploadSession, rd io.Read
 	}
 
 	// image post-processing
-	if info.IsImage() {
+	if info.IsImage() && !info.IsSvg() {
 		if limitErr := checkImageResolutionLimit(info.Width, info.Height, *a.Config().FileSettings.MaxImageResolution); limitErr != nil {
 			return nil, model.NewAppError("uploadData", "app.upload.upload_data.large_image.app_error",
 				map[string]interface{}{"Filename": us.Filename, "Width": info.Width, "Height": info.Height}, "", http.StatusBadRequest)

model/file_info.go

@@ -107,6 +107,10 @@ func (fi *FileInfo) IsImage() bool {
 	return strings.HasPrefix(fi.MimeType, "image")
 }
 
+func (fi *FileInfo) IsSvg() bool {
+	return fi.MimeType == "image/svg+xml"
+}
+
 func NewInfo(name string) *FileInfo {
 	info := &FileInfo{
 		Name: name,

services/slackimport/slackimport.go

@@ -791,7 +791,7 @@ func (si *SlackImporter) oldImportFile(timestamp time.Time, file io.Reader, team
 		return nil, err
 	}
 
-	if fileInfo.IsImage() && fileInfo.MimeType != "image/svg+xml" {
+	if fileInfo.IsImage() && !fileInfo.IsSvg() {
 		img, release, err := si.actions.PrepareImage(data)
 		if err != nil {
 			return nil, err