Fix format string warnings in net/libfetch (was: Re: Initial MirBSD support for pkgsrc)

[Benny Siegert <bsiegert%gmail.com@localhost>]

On Tue, 28 Dec 2010, Greg Troxel wrote:

>  Any changes other than "add MirBSD stanza" probably should be proposed
>  as a separate patch, with rationale as to why it's correct.

As per Greg's request, I am proposing the patch to libfetch separately. 
CCing joerg, the maintainer.

Rationale: On some operating systems, for example on MirBSD, the tm_year 
member of struct tm is not an int but a long, in order to support a 
64-bit time_t. Thus, it is dangerous to use tm_year with a "%d" format 
in printf, the safe way is to cast to long and use "%ld". For scanf, 
using &tm_year as an argument is unsafe as well, thus I used an 
additional int.

Such changes have already been done some time ago in pkg_install, but 
they have not yet been added to libfetch.

Thanks!

--Benny.

Index: net/libfetch/files/ftp.c
===================================================================
RCS file: /cvsroot/pkgsrc/net/libfetch/files/ftp.c,v
retrieving revision 1.36
diff -u -d -r1.36 ftp.c
--- net/libfetch/files/ftp.c    20 Aug 2010 17:56:49 -0000      1.36
+++ net/libfetch/files/ftp.c    28 Dec 2010 15:38:07 -0000
@@ -464,7 +464,7 @@
 {
        char *ln;
        const char *filename;
-       int filenamelen, type;
+       int filenamelen, type, year;
        struct tm tm;
        time_t t;
        int e;
@@ -516,13 +516,13 @@
                return (-1);
        }
        if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
-           &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
+           &year, &tm.tm_mon, &tm.tm_mday,
            &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
                ftp_seterr(FTP_PROTOCOL_ERROR);
                return (-1);
        }
        tm.tm_mon--;
-       tm.tm_year -= 1900;
+       tm.tm_year = year - 1900;
        tm.tm_isdst = -1;
        t = timegm(&tm);
        if (t == (time_t)-1)
Index: net/libfetch/files/http.c
===================================================================
RCS file: /cvsroot/pkgsrc/net/libfetch/files/http.c,v
retrieving revision 1.29
diff -u -d -r1.29 http.c
--- net/libfetch/files/http.c   24 Jan 2010 19:10:35 -0000      1.29
+++ net/libfetch/files/http.c   28 Dec 2010 15:38:08 -0000
@@ -797,9 +797,9 @@
        struct tm tm;
        char buf[80];
        gmtime_r(&last_modified, &tm);
-       snprintf(buf, sizeof(buf), "%.3s, %02d %.3s %4d %02d:%02d:%02d GMT",
+       snprintf(buf, sizeof(buf), "%.3s, %02d %.3s %4ld %02d:%02d:%02d GMT",
            weekdays + tm.tm_wday * 3, tm.tm_mday, months + tm.tm_mon * 3,
-           tm.tm_year + 1900, tm.tm_hour, tm.tm_min, tm.tm_sec);
+           (long)tm.tm_year + 1900, tm.tm_hour, tm.tm_min, tm.tm_sec);
        http_cmd(conn, "If-Modified-Since: %s\r\n", buf);
 }