Fix panic error when the type was not correct when uploading files

src/controllers/upload.go

@@ -20,50 +20,53 @@ func UploadFile(w http.ResponseWriter, r *http.Request) {
 	fmt.Println(r.URL.Path)
 	// Maximum upload of 1000 MB files
 	r.ParseMultipartForm(10000000 << 20)
+	// If the variable files exists
+	if r.MultipartForm != nil {
 
-	// Get handler for filename, size and headers
-	filesHandler := r.MultipartForm.File["files"]
-	for _, handler := range filesHandler {
-		file, err := handler.Open()
-		if err != nil {
-			fmt.Println("Error Retrieving the File")
-			fmt.Println(err)
-			return
-		}
+		// Get handler for filename, size and headers
+		filesHandler := r.MultipartForm.File["files"]
+		for _, handler := range filesHandler {
+			file, err := handler.Open()
+			if err != nil {
+				fmt.Println("Error Retrieving the File")
+				fmt.Println(err)
+				return
+			}
 
-		defer file.Close()
+			defer file.Close()
 
-		// Create file
-		dst, err := os.Create(filepath + "/" + handler.Filename)
-		defer dst.Close()
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
+			// Create file
+			dst, err := os.Create(filepath + "/" + handler.Filename)
+			defer dst.Close()
+			if err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
 
-		// Copy the uploaded file to the created file on the filesystem
-		if _, err := io.Copy(dst, file); err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
+			// Copy the uploaded file to the created file on the filesystem
+			if _, err := io.Copy(dst, file); err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+			f, err := os.Open(filepath)
+			defer f.Close()
+			if err != nil {
+				http.Error(w, "404 Not Found : Error while opening the file.", 404)
+				return
+			}
 		}
-		f, err := os.Open(filepath)
-		defer f.Close()
+		data := struct {
+			Directory string
+			ServerUA  string
+		}{
+			r.URL.Path,
+			serverUA,
+		}
+		err := renderTemplate(w, "upload.tpl", data)
 		if err != nil {
-			http.Error(w, "404 Not Found : Error while opening the file.", 404)
-			return
+			fmt.Print("Error while uploading: ")
+			fmt.Println(err)
 		}
 	}
-	data := struct {
-		Directory string
-		ServerUA  string
-	}{
-		r.URL.Path,
-		serverUA,
-	}
-	err := renderTemplate(w, "upload.tpl", data)
-	if err != nil {
-		fmt.Print("Error while uploading: ")
-		fmt.Println(err)
-	}
 
 }