Fix tzalloc(nullptr) and add a test.
This works (by reading /etc/localtime) on NetBSD, but not on Android
since we have no such file. Fix that by using our equivalent system
property instead.
Also s/time zone/timezone/ in documentation and comments. We've always
been inconsistent about this (as is upstream in code comments and
documentation) but it seems especially odd now we expose a _type_ that
spells it "timezone" to talk of "time zone" even as we're describing
that type and its associated functions.
Bug: https://github.com/chronotope/chrono/issues/499
Test: treehugger
Change-Id: I142995a3ab4deff1073a0aa9e63ce8eac850b93d
diff --git a/libc/tzcode/bionic.cpp b/libc/tzcode/bionic.cpp
index d2b5d80..7091707 100644
--- a/libc/tzcode/bionic.cpp
+++ b/libc/tzcode/bionic.cpp
@@ -36,10 +36,45 @@
#include "private/CachedProperty.h"
extern "C" void tzset_unlocked(void);
+extern "C" void __bionic_get_system_tz(char* buf, size_t n);
extern "C" int __bionic_open_tzdata(const char*, int32_t*);
extern "C" void tzsetlcl(char const*);
+void __bionic_get_system_tz(char* buf, size_t n) {
+ static CachedProperty persist_sys_timezone("persist.sys.timezone");
+ const char* name = persist_sys_timezone.Get();
+
+ // If the system property is not set, perhaps because this is called
+ // before the default value has been set (the recovery image being a
+ // classic example), fall back to GMT.
+ if (name == nullptr) name = "GMT";
+
+ strlcpy(buf, name, n);
+
+ if (!strcmp(buf, "GMT")) {
+ // Typically we'll set the system property to an Olson ID, but
+ // java.util.TimeZone also supports the "GMT+xxxx" style, and at
+ // least historically (see http://b/25463955) some Android-based set
+ // top boxes would get the timezone from the TV network in this format
+ // and use it directly in the system property. This caused trouble
+ // for native code because POSIX and Java disagree about the sign in
+ // a timezone string. For POSIX, "GMT+3" means "3 hours west/behind",
+ // but for Java it means "3 hours east/ahead". Since (a) Java is the
+ // one that matches human expectations and (b) this system property is
+ // used directly by Java, we flip the sign here to translate from Java
+ // to POSIX. We only need to worry about the "GMT+xxxx" case because
+ // the expectation is that these are valid java.util.TimeZone ids,
+ // not general POSIX custom timezone specifications (which is why this
+ // code only applies to the system property, and not to the environment
+ // variable).
+ char sign = buf[3];
+ if (sign == '-' || sign == '+') {
+ buf[3] = (sign == '-') ? '+' : '-';
+ }
+ }
+}
+
void tzset_unlocked() {
// The TZ environment variable is meant to override the system-wide setting.
const char* name = getenv("TZ");
@@ -47,26 +82,10 @@
// If that's not set, look at the "persist.sys.timezone" system property.
if (name == nullptr) {
- static CachedProperty persist_sys_timezone("persist.sys.timezone");
-
- if ((name = persist_sys_timezone.Get()) != nullptr && strlen(name) > 3) {
- // POSIX and Java disagree about the sign in a timezone string. For POSIX, "GMT+3" means
- // "3 hours west/behind", but for Java it means "3 hours east/ahead". Since (a) Java is
- // the one that matches human expectations and (b) this system property is used directly
- // by Java, we flip the sign here to translate from Java to POSIX. http://b/25463955.
- char sign = name[3];
- if (sign == '-' || sign == '+') {
- strlcpy(buf, name, sizeof(buf));
- buf[3] = (sign == '-') ? '+' : '-';
- name = buf;
- }
- }
+ __bionic_get_system_tz(buf, sizeof(buf));
+ name = buf;
}
- // If the system property is also not available (because you're running AOSP on a WiFi-only
- // device, say), fall back to GMT.
- if (name == nullptr) name = "GMT";
-
tzsetlcl(name);
}
@@ -192,14 +211,14 @@
close(fd);
// This file descriptor (-1) is passed to localtime.c. In invalid fd case
// upstream passes errno value around methods and having 0 there will
- // indicate that time zone was found and read successfully and localtime's
+ // indicate that timezone was found and read successfully and localtime's
// internal state was properly initialized (which wasn't as we couldn't find
- // requested time zone in the tzdata file).
+ // requested timezone in the tzdata file).
// If we reached this point errno is unlikely to be touched. It is only
// close(fd) which can do it, but that is very unlikely to happen. And
// even if it happens we can't extract any useful insights from it.
// We are overriding it to ENOENT as it matches upstream expectations -
- // time zone is absent in the tzdata file == there is no TZif file in
+ // timezone is absent in the tzdata file == there is no TZif file in
// /usr/share/zoneinfo.
errno = ENOENT;
return -1;
@@ -219,7 +238,7 @@
int fd;
// Try the two locations for the tzdata file in a strict order:
- // 1: The time zone data module which contains the main copy. This is the
+ // 1: The timezone data module which contains the main copy. This is the
// common case for current devices.
// 2: The ultimate fallback: the non-updatable copy in /system.
diff --git a/libc/tzcode/localtime.c b/libc/tzcode/localtime.c
index 5e1181f..018acad 100644
--- a/libc/tzcode/localtime.c
+++ b/libc/tzcode/localtime.c
@@ -374,8 +374,11 @@
+ 4 * TZ_MAX_TIMES];
};
-// Android-removed: There is no directory with file-per-time zone on Android.
-#ifndef __BIONIC__
+#if defined(__BIONIC__)
+// Android: there is no directory with one file per timezone on Android,
+// but we do have a system property instead.
+#include <sys/system_properties.h>
+#else
/* TZDIR with a trailing '/' rather than a trailing '\0'. */
static char const tzdirslash[sizeof TZDIR] = TZDIR "/";
#endif
@@ -415,13 +418,20 @@
#endif
register union input_buffer *up = &lsp->u.u;
register int tzheadsize = sizeof(struct tzhead);
+ char system_tz_name[PROP_VALUE_MAX];
sp->goback = sp->goahead = false;
if (! name) {
+#if defined(__BIONIC__)
+ extern void __bionic_get_system_tz(char* , size_t);
+ __bionic_get_system_tz(system_tz_name, sizeof(system_tz_name));
+ name = system_tz_name;
+#else
name = TZDEFAULT;
if (! name)
return EINVAL;
+#endif
}
#if defined(__BIONIC__)