time: fix incorrect DST offset when using POSIX timezones without DST

[musl] / src / time / __tz.c

diff --git a/src/time/__tz.c b/src/time/__tz.c
index 8b84b9b..814edcd 100644 (file)
--- a/src/time/__tz.c
+++ b/src/time/__tz.c
@@ -15,7 +15,7 @@ weak_alias(__tzname, tzname);
 
 static char std_name[TZNAME_MAX+1];
 static char dst_name[TZNAME_MAX+1];
-const char __gmt[] = "GMT";
+const char __utc[] = "UTC";
 
 static int dst_off;
 static int r0[5], r1[5];
@@ -27,7 +27,7 @@ static char old_tz_buf[32];
 static char *old_tz = old_tz_buf;
 static size_t old_tz_size = sizeof old_tz_buf;
 
-static volatile int lock[2];
+static volatile int lock[1];
 
 static int getint(const char **p)
 {
@@ -84,7 +84,7 @@ static void getname(char *d, const char **p)
        int i;
        if (**p == '<') {
                ++*p;
-               for (i=0; **p!='>' && i<TZNAME_MAX; i++)
+               for (i=0; (*p)[i]!='>' && i<TZNAME_MAX; i++)
                        d[i] = (*p)[i];
                ++*p;
        } else {
@@ -126,7 +126,7 @@ static void do_tzset()
 
        s = getenv("TZ");
        if (!s) s = "/etc/localtime";
-       if (!*s) s = __gmt;
+       if (!*s) s = __utc;
 
        if (old_tz && !strcmp(s, old_tz)) return;
 
@@ -136,7 +136,7 @@ static void do_tzset()
         * free so as not to pull it into static programs. Growth
         * strategy makes it so free would have minimal benefit anyway. */
        i = strlen(s);
-       if (i > PATH_MAX+1) s = __gmt, i = 3;
+       if (i > PATH_MAX+1) s = __utc, i = 3;
        if (i >= old_tz_size) {
                old_tz_size *= 2;
                if (i >= old_tz_size) old_tz_size = i+1;
@@ -165,12 +165,12 @@ static void do_tzset()
                                }
                        }
                }
-               if (!map) s = __gmt;
+               if (!map) s = __utc;
        }
        if (map && (map_size < 44 || memcmp(map, "TZif", 4))) {
                __munmap((void *)map, map_size);
                map = 0;
-               s = __gmt;
+               s = __utc;
        }
 
        zi = map;
@@ -207,7 +207,7 @@ static void do_tzset()
                                }
                        }
                        if (!__tzname[0]) __tzname[0] = __tzname[1];
-                       if (!__tzname[0]) __tzname[0] = (char *)__gmt;
+                       if (!__tzname[0]) __tzname[0] = (char *)__utc;
                        if (!__daylight) {
                                __tzname[1] = __tzname[0];
                                dst_off = __timezone;
@@ -216,7 +216,7 @@ static void do_tzset()
                }
        }
 
-       if (!s) s = __gmt;
+       if (!s) s = __utc;
        getname(std_name, &s);
        __tzname[0] = std_name;
        __timezone = getoff(&s);
@@ -230,7 +230,7 @@ static void do_tzset()
                        dst_off = __timezone - 3600;
        } else {
                __daylight = 0;
-               dst_off = 0;
+               dst_off = __timezone;
        }
 
        if (*s == ',') s++, getrule(&s, r0);
@@ -373,18 +373,14 @@ void __secs_to_zone(long long t, int local, int *isdst, long *offset, long *oppo
        long long t0 = rule_to_secs(r0, y);
        long long t1 = rule_to_secs(r1, y);
 
+       if (!local) {
+               t0 += __timezone;
+               t1 += dst_off;
+       }
        if (t0 < t1) {
-               if (!local) {
-                       t0 += __timezone;
-                       t1 += dst_off;
-               }
                if (t >= t0 && t < t1) goto dst;
                goto std;
        } else {
-               if (!local) {
-                       t1 += __timezone;
-                       t0 += dst_off;
-               }
                if (t >= t1 && t < t0) goto std;
                goto dst;
        }
@@ -417,7 +413,7 @@ const char *__tm_to_tzname(const struct tm *tm)
        const void *p = tm->__tm_zone;
        LOCK(lock);
        do_tzset();
-       if (p != __gmt && p != __tzname[0] && p != __tzname[1] &&
+       if (p != __utc && p != __tzname[0] && p != __tzname[1] &&
            (!zi || (uintptr_t)p-(uintptr_t)abbrevs >= abbrevs_end - abbrevs))
                p = "";
        UNLOCK(lock);