fix: enhance app icon download logic to include file existence check (#11796)

* fix: enhance app icon download logic to include file existence check

- Updated the downloadAppIcon function to parse the icon field for the file name and ETag.
- Added a condition to check if the icon file exists before setting the If-None-Match header for the request.

* fix: improve app icon retrieval logic by adding filename check

- Updated GetAppIcon method to include filename in the response.
- Added a condition to ensure the ETag header is set only if both ETag and filename are present, enhancing the integrity of the caching mechanism.

Author: HynoR

agent/app/api/v2/app.go

@@ -210,7 +210,7 @@ func (b *BaseApi) GetAppIcon(c *gin.Context) {
 		helper.BadRequest(c, err)
 		return
 	}
-	iconBytes, _, etag, err := appService.GetAppIcon(appKey)
+	iconBytes, filename, etag, err := appService.GetAppIcon(appKey)
 	if err != nil {
 		helper.InternalServer(c, err)
 		return
@@ -223,7 +223,7 @@ func (b *BaseApi) GetAppIcon(c *gin.Context) {
 
 	c.Header("Cache-Control", "public, max-age=2592000")
 
-	if etag != "" {
+	if etag != "" && filename != "" {
 		c.Header("ETag", etag)
 		if c.GetHeader("If-None-Match") == etag {
 			c.Status(http.StatusNotModified)

agent/app/service/app_sync_task.go

@@ -221,10 +221,10 @@ func (c *appSyncContext) syncAppIconsAndDetails() error {
 }
 
 func (c *appSyncContext) downloadAppIcon(iconUrl, appKey, oldIcon string) (status int, iconField string) {
-	existingEtag := appicon.GetETagFromIconField(oldIcon)
+	iconFileName, existingEtag := appicon.ParseIconField(oldIcon)
 
 	reqHeaders := make(map[string]string)
-	if existingEtag != "" {
+	if existingEtag != "" && iconFileName != "" && appicon.IconFileExists(iconFileName) {
 		reqHeaders["If-None-Match"] = existingEtag
 	}