Error handling. Vendoring

Signed-off-by: Ettore Dreucci <ettore.dreucci@gmail.com>

vendor/gopkg.in/tucnak/telebot.v2/file.go

@@ -0,0 +1,70 @@
+package telebot
+
+import (
+	"os"
+)
+
+// File object represents any sort of file.
+type File struct {
+	FileID   string `json:"file_id"`
+	FileSize int    `json:"file_size"`
+
+	// file on telegram server https://core.telegram.org/bots/api#file
+	FilePath string `json:"file_path"`
+
+	// file on local file system.
+	FileLocal string `json:"file_local"`
+
+	// file on the internet
+	FileURL string `json:"file_url"`
+}
+
+// FromDisk constructs a new local (on-disk) file object.
+//
+// Note, it returns File, not *File for a very good reason:
+// in telebot, File is pretty much an embeddable struct,
+// so upon uploading media you'll need to set embedded File
+// with something. NewFile() returning File makes it a one-liner.
+//
+//     photo := &tb.Photo{File: tb.FromDisk("chicken.jpg")}
+//
+func FromDisk(filename string) File {
+	return File{FileLocal: filename}
+}
+
+// FromURL constructs a new file on provided HTTP URL.
+//
+// Note, it returns File, not *File for a very good reason:
+// in telebot, File is pretty much an embeddable struct,
+// so upon uploading media you'll need to set embedded File
+// with something. NewFile() returning File makes it a one-liner.
+//
+//     photo := &tb.Photo{File: tb.FromURL("https://site.com/picture.jpg")}
+//
+func FromURL(url string) File {
+	return File{FileURL: url}
+}
+
+func (f *File) stealRef(g *File) {
+	if g.OnDisk() {
+		f.FileLocal = g.FileLocal
+	}
+
+	if g.FileURL != "" {
+		f.FileURL = g.FileURL
+	}
+}
+
+// InCloud tells whether the file is present on Telegram servers.
+func (f *File) InCloud() bool {
+	return f.FileID != ""
+}
+
+// OnDisk will return true if file is present on disk.
+func (f *File) OnDisk() bool {
+	if _, err := os.Stat(f.FileLocal); err != nil {
+		return false
+	}
+
+	return true
+}