update vendor/

vendor/github.com/cavaliercoder/grab/error.go

@@ -0,0 +1,42 @@
+package grab
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+var (
+	// ErrBadLength indicates that the server response or an existing file does
+	// not match the expected content length.
+	ErrBadLength = errors.New("bad content length")
+
+	// ErrBadChecksum indicates that a downloaded file failed to pass checksum
+	// validation.
+	ErrBadChecksum = errors.New("checksum mismatch")
+
+	// ErrNoFilename indicates that a reasonable filename could not be
+	// automatically determined using the URL or response headers from a server.
+	ErrNoFilename = errors.New("no filename could be determined")
+
+	// ErrNoTimestamp indicates that a timestamp could not be automatically
+	// determined using the response headers from the remote server.
+	ErrNoTimestamp = errors.New("no timestamp could be determined for the remote file")
+
+	// ErrFileExists indicates that the destination path already exists.
+	ErrFileExists = errors.New("file exists")
+)
+
+// StatusCodeError indicates that the server response had a status code that
+// was not in the 200-299 range (after following any redirects).
+type StatusCodeError int
+
+func (err StatusCodeError) Error() string {
+	return fmt.Sprintf("server returned %d %s", err, http.StatusText(int(err)))
+}
+
+// IsStatusCodeError returns true if the given error is of type StatusCodeError.
+func IsStatusCodeError(err error) bool {
+	_, ok := err.(StatusCodeError)
+	return ok
+}