allow zoneinfo-path-relative filenames with no slashes in TZ variable

since the form TZ=name is reserved for POSIX-form time zone strings,
TZ=:name needs to be used when the zoneinfo filename is in the
top-level zoneinfo directory and therefore does not contain a slash.
previously the leading colon was merely dropped, making it impossible
to access such zones without a full absolute pathname.

changes based on patch by Timo Teräs.

diff --git a/src/time/__tz.c b/src/time/__tz.c
index 9d56a618f2d58c7084c26096bc04b05280210866..fbe3d4921532e5bd70e13acf953c77045b55f42e 100644 (file)
--- a/src/time/__tz.c
+++ b/src/time/__tz.c
@@ -121,7 +121,7 @@ int __munmap(void *, size_t);
 static void do_tzset()
 {
        char buf[NAME_MAX+25], *pathname=buf+24;
-       const char *try, *s;
+       const char *try, *s, *p;
        const unsigned char *map = 0;
        size_t i;
        static const char search[] =
@@ -147,19 +147,16 @@ static void do_tzset()
        }
        if (old_tz) memcpy(old_tz, s, i+1);
 
-       if (*s == ':') s++;
-
        /* Non-suid can use an absolute tzfile pathname or a relative
         * pathame beginning with "."; in secure mode, only the
         * standard path will be searched. */
-       if (*s == '/' || *s == '.') {
-               if (!libc.secure) map = __map_file(s, &map_size);
-       } else {
-               for (i=0; s[i] && s[i]!=','; i++) {
-                       if (s[i]=='/') {
-                               size_t l = strlen(s);
-                               if (l > NAME_MAX || strchr(s, '.'))
-                                       break;
+       if (*s == ':' || ((p=strchr(s, '/')) && !memchr(s, ',', p-s))) {
+               if (*s == ':') s++;
+               if (*s == '/' || *s == '.') {
+                       if (!libc.secure) map = __map_file(s, &map_size);
+               } else {
+                       size_t l = strlen(s);
+                       if (l <= NAME_MAX && !strchr(s, '.')) {
                                memcpy(pathname, s, l+1);
                                pathname[l] = 0;
                                for (try=search; !map && *try; try+=l+1) {
@@ -167,7 +164,6 @@ static void do_tzset()
                                        memcpy(pathname-l, try, l);
                                        map = __map_file(pathname-l, &map_size);
                                }
-                               break;
                        }
                }
        }