Fix calculation of ISMN check digit.

This has always been broken, so back-patch to all supported versions.

Fabien COELHO

diff --git a/contrib/isn/isn.c b/contrib/isn/isn.c
index 181bbd407211dda0f2e9d33c5f3fd9e9d438ec44..c7e96022ebaef283bbb690ae7a58f8902841e548 100644 (file)
--- a/contrib/isn/isn.c
+++ b/contrib/isn/isn.c
@@ -827,7 +827,7 @@ string2ean(const char *str, bool errorOK, ean13 *result,
                case ISMN:
                        strncpy(buf, "9790", 4);        /* this isn't for sure yet, for now
                                                                                 * ISMN it's only 9790 */
-                       valid = (valid && ((rcheck = checkdig(buf + 3, 10)) == check || magic));
+                       valid = (valid && ((rcheck = checkdig(buf, 13)) == check || magic));
                        break;
                case ISBN:
                        strncpy(buf, "978", 3);