Re: [PATCH 1/7] submodule--helper: add valid-label-name

Stefan Beller [off-list ref] writes:

+static int submodule_valid_label_name(const char *label)
+{
+	if (!label || !strlen(label))
+		return 0;
+
+	if (!isalnum(*label))
+		return 0;

I'd limit this one to isalpha() if I were doing this to make the
restriction similar to identifiers in traditional programming
language.

+	while (*label) {
+		if (!(isalnum(*label) ||
+			*label == '-'))

And throw in '_' to the mix while at it.

+			return 0;
+		label++;
+	}
+
+	return 1;
+}

If the convention is "0 is good", then please signal "bad" with a
negative value, not just "non-zero".