tests/ansi: add test case for TZ environment variable behaviour

Author: lzcunt

tests/ansi/tz.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+#include <time.h>
+
+extern int daylight;
+extern long timezone;
+extern char *tzname[2];
+
+int main() {
+	tzset();
+	printf("%s %ld %d\n", tzname[0], timezone, daylight);
+	return 0;
+}

tests/ansi/tz.py

@@ -0,0 +1,47 @@
+import subprocess
+import sys
+import os
+from pyexpect import expect
+
+wrapper = os.getenv("MESON_EXE_WRAPPER")
+wrapper = [x for x in (wrapper,) if x]
+
+def check_tz(tz, expected):
+	output = subprocess.check_output(
+		wrapper + [sys.argv[1]],
+		stderr=subprocess.STDOUT,
+		env={"TZ": tz},
+	)
+
+	expect(expected).to_equal(output)
+
+check_tz("UTC0", b"UTC 0 0\n")
+check_tz("GMT0", b"GMT 0 0\n")
+check_tz(":UTC0", b"UTC 0 0\n")
+check_tz("EST+5", b"EST 18000 0\n")
+check_tz("EET-2", b"EET -7200 0\n")
+check_tz("<+03>-03", b"+03 -10800 0\n")
+check_tz("NZST-12", b"NZST -43200 0\n")
+check_tz("NST+03:40", b"NST 13200 0\n")
+check_tz("NPT-05:45", b"NPT -20700 0\n")
+
+# These depend on tzdata, which may or may not exist.
+# Useful to check every now and then, but these also present subtle differences
+# between the host libc and mlibc, so we can't expect these to always hold up.
+# E.g. glibc will set `tzname` from the TZ environment variable even if it
+# cannot find the tzinfo file, however mlibc will use the name of the timezone
+# as read from the tzinfo file or the timezone that it defaults to (UTC).
+
+# Would be b"Universal 0 0\n" on glibc.
+# check_tz("", b"UTC 0 0\n")
+
+# check_tz("UTC", b"UTC 0 0\n")
+# check_tz(":UTC", b"UTC 0 0\n")
+
+# Would be b"Universal 0 0\n" on glibc.
+# check_tz("Universal", b"UTC 0 0\n")
+# check_tz(":Universal", b"UTC 0 0\n")
+
+# Would be b"ATimeZoneThatShouldHopefullyNeverBeInTzdata 0 0\n" on glibc.
+# check_tz("ATimeZoneThatShouldHopefullyNeverBeInTzdata", b"UTC 0 0\n")
+# check_tz(":ATimeZoneThatShouldHopefullyNeverBeInTzdata", b"UTC 0 0\n")

tests/meson.build

@@ -18,6 +18,7 @@ all_test_cases = [
 	'ansi/wcsrtombs',
 	'ansi/wmemcmp',
 	'ansi/timegm',
+	'ansi/tz',
 	'ansi/ungetc',
 	'ansi/wcsdup',
 	'ansi/wcsncasecmp',
@@ -130,6 +131,7 @@ fail_test_cases = [
 ]
 
 wrapped_test_cases = [
+	'ansi/tz',
 	'glibc/error',
 	'glibc/error_at_line',
 ]