Re: [PATCH] conforming strverscmp() implementation

[Sergey Dmitrouk <sdmitrouk@accesssoftek.com>]

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On Tue, Mar 03, 2015 at 07:54:11AM -0800, Rich Felker wrote:
> Have you run libc-test against it and checked that it
> fixes all the test failures there? I would guess it does since they're
> based on the man page examples but it would be good to double-check
> anyway if you haven't.

Yes, related libc-test regression tests pass now.  I also compared
results with glibc implementation and it seems to be correct for
numbers, but I just run check again in directory with some non-ASCII file
names and got:

glibc:      . .. 000 00 01 010 02 03 04 05 06 07 08 09 0 1 3 9 10 11 русские буквы в имени
musl (new): русские буквы в имени . .. 000 00 01 010 02 03 04 05 06 07 08 09 0 1 3 9 10 11
musl (old): русские буквы в имени . .. 0 00 000 01 010 02 03 04 05 06 07 08 09 1 3 9 10 11

You can see that sorting of Cyrillic file names differs from glibc in
UTF-8 locale.  I believe it's another bug and this one is related to:

    return (*l - *r);

which should be changed (maybe even for 1.1.6) to something equivalent to:

    return ((unsigned char)*l - (unsigned char)*r);

in which case results become:

glibc:      . .. 000 00 01 010 02 03 04 05 06 07 08 09 0 1 3 9 10 11 русские буквы в имени
musl (new): . .. 000 00 01 010 02 03 04 05 06 07 08 09 0 1 3 9 10 11 русские буквы в имени
musl (old): . .. 0 00 000 01 010 02 03 04 05 06 07 08 09 1 3 9 10 11 русские буквы в имени

-- 
Sergey

[-- Attachment #2: strverscmp.c --]
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#define _GNU_SOURCE
#include <ctype.h>
#include <string.h>

int strverscmp(const char *l, const char *r)
{
	const char *ln=(isdigit(*l) ? l : NULL), *rn=(isdigit(*r) ? r : NULL);
	while (*l==*r) {
		if (!*l) return 0;

		if (isdigit(*l)) {
			if (ln == NULL) {
				ln = l; rn = r;
			}
		} else {
			ln = NULL; rn = NULL;
		}

		l++; r++;
	}

	if ((*l != '\0' && !isdigit(*l)) || (*r != '\0' && !isdigit(*r))) {
		ln = NULL; rn = NULL;
	}

	if (ln != NULL) {
		int intl=(*ln != '0' || !isdigit(*(ln + 1)));
		int intr=(*rn != '0' || !isdigit(*(rn + 1)));

		if (intl ^ intr) {
			return intl ? 1 : -1;
		} else if (intl) {
			size_t lenl=0, lenr=0;
			while (isdigit(l[lenl])) lenl++;
			while (isdigit(r[lenr])) lenr++;
			if (lenl==lenr) {
				return ((unsigned char)*l - (unsigned char)*r);
			} else if (lenl>lenr) {
				return 1;
			} else {
				return -1;
			}
		} else {
			size_t zl=0, zr=0;
			while (ln[zl]=='0') zl++;
			while (rn[zr]=='0') zr++;
			if (zl>zr) {
				return -1;
			} else if (zl<zr) {
				return 1;
			}
		}
	}

	return ((unsigned char)*l - (unsigned char)*r);
}