Re: [PATCHv4] fast-import: tighten parsing of datarefs

Pete Wyckoff [off-list ref] writes:

The syntax for the use of mark references in fast-import
demands either a SP (space) or LF (end-of-line) after
a mark reference.  Fast-import does not complain when garbage
appears after a mark reference in some cases.

Factor out parsing of mark references and complain if
errant characters are found.  Also be a little more careful
when parsing "inline" and SHA1s, complaining if extra
characters appear or if the form of the dataref is unrecognized.

+static uintmax_t parse_mark_ref(const char *p, char **endptr)
+{
+	uintmax_t mark;
+
+	assert(*p == ':');
+	++p;
+	mark = strtoumax(p, endptr, 10);
+	if (*endptr == p)
+		die("No value after ':' in mark: %s", command_buf.buf);
+	return mark;
+}

+static uintmax_t parse_mark_ref_eol(const char *p)
+{
+...
+}
+
+static uintmax_t parse_mark_ref_space(const char **p)
+{
+...
+}
+

The first helper looks sensible, but the two seemingly similar
parse_mark_ref_WHATTOEXPECT() that have different interfaces are somewhat
tasteless.

I wonder if the calling sites in file_change_m(), note_change_n(),
parse_merge(), parse_cat_blob() and parse_treeish_dataref() can be made to
share even more code by slight restructuring, though.