From 02c80bd445aecdcfdf1a34cfc2e1a7ac99e93e8d Mon Sep 17 00:00:00 2001
From: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Date: Thu, 31 Mar 2022 23:11:17 +0200
Subject: [PATCH] time:  fix repetitive time.now().local().local().local()
 offsetting the time further and further (#13861)

---
 vlib/time/time.c.v         | 4 ++++
 vlib/time/time.v           | 3 ++-
 vlib/time/time_nix.c.v     | 6 +++++-
 vlib/time/time_test.v      | 9 +++++++++
 vlib/time/time_windows.c.v | 1 +
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/vlib/time/time.c.v b/vlib/time/time.c.v
index 503c4815f5..9816706dfd 100644
--- a/vlib/time/time.c.v
+++ b/vlib/time/time.c.v
@@ -117,5 +117,9 @@ fn convert_ctime(t C.tm, microsecond int) Time {
 		second: t.tm_sec
 		microsecond: microsecond
 		unix: make_unix_time(t)
+		// for the actual code base when we
+		// call convert_ctime, it is always
+		// when we manage the local time.
+		is_local: true
 	}
 }
diff --git a/vlib/time/time.v b/vlib/time/time.v
index 3a7eff3a59..986d729cfe 100644
--- a/vlib/time/time.v
+++ b/vlib/time/time.v
@@ -45,6 +45,7 @@ pub:
 	second      int
 	microsecond int
 	unix        i64
+	is_local    bool // used to make time.now().local().local() == time.now().local()
 }
 
 // FormatDelimiter contains different time formats.
@@ -348,7 +349,7 @@ pub fn (d Duration) str() string {
 
 // offset returns time zone UTC offset in seconds.
 pub fn offset() int {
-	t := now()
+	t := utc()
 	local := t.local()
 	return int(local.unix - t.unix)
 }
diff --git a/vlib/time/time_nix.c.v b/vlib/time/time_nix.c.v
index 5d88b6ff8e..7bf12f3222 100644
--- a/vlib/time/time_nix.c.v
+++ b/vlib/time/time_nix.c.v
@@ -20,7 +20,8 @@ struct C.tm {
 
 fn C.timegm(&C.tm) C.time_t
 
-// fn C.gmtime_r(&tm, &gbuf)
+// prefering localtime_r over the localtime because
+// from docs localtime_r is thread safe,
 fn C.localtime_r(t &C.time_t, tm &C.tm)
 
 fn make_unix_time(t C.tm) i64 {
@@ -29,6 +30,9 @@ fn make_unix_time(t C.tm) i64 {
 
 // local returns t with the location set to local time.
 pub fn (t Time) local() Time {
+	if t.is_local {
+		return t
+	}
 	loc_tm := C.tm{}
 	C.localtime_r(voidptr(&t.unix), &loc_tm)
 	return convert_ctime(loc_tm, t.microsecond)
diff --git a/vlib/time/time_test.v b/vlib/time/time_test.v
index 66da15b459..c657b2c8ce 100644
--- a/vlib/time/time_test.v
+++ b/vlib/time/time_test.v
@@ -254,3 +254,12 @@ fn test_since() {
 	d2 := time.since(t1)
 	assert d2 >= 40_000_000
 }
+
+// issue relate https://github.com/vlang/v/issues/13828
+// problem: the local method add 2h on the time in a Linux machine
+// the other machine are not tested in a local env
+fn test_recursive_local_call() {
+	now_tm := time.now()
+	assert now_tm.str() == now_tm.local().str()
+	assert now_tm.local().str() == now_tm.local().local().str()
+}
diff --git a/vlib/time/time_windows.c.v b/vlib/time/time_windows.c.v
index 0b676db4d2..19d2e71e36 100644
--- a/vlib/time/time_windows.c.v
+++ b/vlib/time/time_windows.c.v
@@ -104,6 +104,7 @@ pub fn (t Time) local() Time {
 		hour: u16(t.hour)
 		minute: u16(t.minute)
 		second: u16(t.second)
+		millisecond: u16(t.microsecond / 1000)
 	}
 	st_local := SystemTime{}
 	C.SystemTimeToTzSpecificLocalTime(voidptr(0), &st_utc, &st_local)