From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_MSPIKE_H2 autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 5049 invoked from network); 8 Nov 2022 03:25:24 -0000 Received: from second.openwall.net (193.110.157.125) by inbox.vuxu.org with ESMTPUTF8; 8 Nov 2022 03:25:24 -0000 Received: (qmail 3374 invoked by uid 550); 8 Nov 2022 03:25:22 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 3338 invoked from network); 8 Nov 2022 03:25:21 -0000 Date: Mon, 7 Nov 2022 22:25:09 -0500 From: Rich Felker To: Dmitry Bogatov Cc: bug-gsasl@gnu.org, musl@lists.openwall.com Message-ID: <20221108032509.GH29905@brightrain.aerifal.cx> References: <20221106233904.GE29905@brightrain.aerifal.cx> <20221108030824.GG29905@brightrain.aerifal.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221108030824.GG29905@brightrain.aerifal.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Subject: Re: [musl] Behaviour of strverscmp(3) On Mon, Nov 07, 2022 at 10:08:25PM -0500, Rich Felker wrote: > On Sun, Nov 06, 2022 at 06:39:04PM -0500, Rich Felker wrote: > > On Sun, Nov 06, 2022 at 06:18:22PM -0500, Dmitry Bogatov wrote: > > > Hello. > > > > > > While trying to building gsasl statically with musl library as part of > > > Nixpkgs distribution, I noticed that test built from tests/version.c > > > fails when built with musl library. After a bit of troubleshooting, I > > > can pinpoint the reason -- different behaviour of "strverscmp" from > > > glibc and musl. > > > > > > Example code: > > > > > > #include > > > #include > > > > > > int main() > > > { > > > int value = strverscmp("UNKNOWN", "2.2.0"); > > > printf("%d\n", value); > > > return 0; > > > } > > > > > > Under glibc value "35" is printed (positive), under musl value "-1" is > > > printed (negative). Not sure what is the correct solution for the > > > issue, so I cross-post into two lists. > > > > > > For now I plan to patch-out this particular test. Thank you. > > > > It looks like we're neglecting to honor the exception case to "longer > > digit sequence is greater" when one of the sequences is degenerate (no > > digits). > > I think the attached patch fixes it in the most non-invasive way > that's most clear in avoiding other unwanted side effects. It > basically says "only apply the longest-digit-sequence" rule if there > is a common nonzero length [[:digit:]]+ match (dp is the position > where digit sequence starts, j is the test position). > > I think this code should be reviewed for additional bugs though. > > Rich > diff --git a/src/string/strverscmp.c b/src/string/strverscmp.c > index 4daf276d..9e35422a 100644 > --- a/src/string/strverscmp.c > +++ b/src/string/strverscmp.c > @@ -22,8 +22,8 @@ int strverscmp(const char *l0, const char *r0) > /* If we're not looking at a digit sequence that began > * with a zero, longest digit string is greater. */ > for (j=i; isdigit(l[j]); j++) > - if (!isdigit(r[j])) return 1; > - if (isdigit(r[j])) return -1; > + if (dp + if (dp } else if (z && dp /* Otherwise, if common prefix of digit sequence is > * all zeros, digits order less than non-digits. */ An alternate way to do this might be changing the condition for the if block: - if (l[dp]!='0' && r[dp]!='0') { + if (l[dp]-'1'<9U && r[dp]-'1'<9U) { That is, only doing the longest-digit-sequence logic at all if both l and r have a nonzero digit at dp. This is probably more efficient. Rich