Merge branch 'jk/osxkeychain-username-is-nul-terminated' into maint-2.46

The credential helper to talk to OSX keychain sometimes sent
garbage bytes after the username, which has been corrected.

* jk/osxkeychain-username-is-nul-terminated:
  credential/osxkeychain: respect NUL terminator in username

contrib/credential/osxkeychain/git-credential-osxkeychain.c

@@ -141,7 +141,7 @@ static void find_username_in_item(CFDictionaryRef item)
 				username_buf,
 				buffer_len,
 				ENCODING)) {
-		write_item("username", username_buf, buffer_len - 1);
+		write_item("username", username_buf, strlen(username_buf));
 	}
 	free(username_buf);
 }