Re: [PATCH 1/1] rebase -r: let `label` generate safer labels

Johannes Schindelin [off-list ref] writes:

If you care deeply about double dashes and leading dashes, how about
this instead?

		char *from, *to;

   		for (from = to = label.buf; *from; from++)
			if ((*from & 0x80) || isalnum(*from))
				*(to++) = *from;
			/* avoid leading dash and double-dashes */
			else if (to != label.buf && to[-1] != '-')
   				*(to++) = '-';
		strbuf_setlen(&label, to - label.buf);

Simple enough and is a good change when judged locally.

It still would cause readers to wonder if label_oid() later append
'-%d' to end up with double-dash near the end, etc., which made me
wonder if the resulting code becomes better if sanitization and
uniquefying are done at the same single place in the other message.