fix strverscmp comparison of digit sequence with non-digits
Commit Message
>From: Rich Felker <dalias@aerifal.cx>
Date: Mon, 7 Nov 2022 22:17:55 -0500
the rule that longest digit sequence not beginning with a zero is
greater only applies when both sequences being compared are
non-degenerate. this is spelled out explicitly in the man page, which
may be deemed authoritative for this nonstandard function: "If one or
both of these is empty, then return what strcmp(3) would have
returned..."
we were wrongly treating any sequence of digits not beginning with a
zero as greater than a non-digit in the other string.
Signed-off-by: Brian Inglis <Brian.Inglis@SystematicSW.ab.ca>
---
newlib/libc/string/strverscmp.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
Comments
On Jan 8 06:56, Brian Inglis wrote:
> >From: Rich Felker <dalias@aerifal.cx>
> Date: Mon, 7 Nov 2022 22:17:55 -0500
>
> the rule that longest digit sequence not beginning with a zero is
> greater only applies when both sequences being compared are
> non-degenerate. this is spelled out explicitly in the man page, which
> may be deemed authoritative for this nonstandard function: "If one or
> both of these is empty, then return what strcmp(3) would have
> returned..."
>
> we were wrongly treating any sequence of digits not beginning with a
> zero as greater than a non-digit in the other string.
>
> Signed-off-by: Brian Inglis <Brian.Inglis@SystematicSW.ab.ca>
> ---
> newlib/libc/string/strverscmp.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Pushed.
Thanks,
Corinna
@@ -76,9 +76,9 @@ int strverscmp(const char *l0, const char *r0)
else if (c!='0') z=0;
}
- if (l[dp]!='0' && r[dp]!='0') {
- /* If we're not looking at a digit sequence that began
- * with a zero, longest digit string is greater. */
+ if (l[dp]-'1'<9U && r[dp]-'1'<9U) {
+ /* If we're looking at non-degenerate digit sequences starting
+ * with nonzero digits, longest digit string is greater. */
for (j=i; isdigit(l[j]); j++)
if (!isdigit(r[j])) return 1;
if (isdigit(r[j])) return -1;