From dbc9f68758b45aa91854e17240e2b2128dc886a0 Mon Sep 17 00:00:00 2001
From: Tobias Rapp <t.rapp@noa-archive.com>
Date: Fri, 3 Nov 2023 14:02:31 +0100
Subject: [PATCH] Apply timezone when mapping from Timestamp to chrono Date and
 DateTime

Update FromSql implementation of Date<Utc>, Date<Local>, DateTime<Utc>,
and DateTime<Local> to map the incoming timezone information, when
available.

To explicitly ignore the timezone information use of the NaiveDate /
NaiveDateTime types would be preferred.
---
 src/sql_type/chrono.rs | 28 ++++++++++++++++++++++++----
 tests/from_to_sql.rs   | 26 ++++++++++++++++++--------
 2 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/src/sql_type/chrono.rs b/src/sql_type/chrono.rs
index e1fbc0ed..3006afc6 100644
--- a/src/sql_type/chrono.rs
+++ b/src/sql_type/chrono.rs
@@ -64,14 +64,24 @@ where
 impl FromSql for DateTime<Utc> {
     fn from_sql(val: &SqlValue) -> Result<DateTime<Utc>> {
         let ts = val.to_timestamp()?;
-        datetime_from_sql(&Utc, &ts)
+        if ts.with_tz() {
+            datetime_from_sql(&fixed_offset_from_sql(&ts)?, &ts)
+                .map(|val| val.with_timezone(&Utc))
+        } else {
+            datetime_from_sql(&Utc, &ts)
+        }
     }
 }
 
 impl FromSql for DateTime<Local> {
     fn from_sql(val: &SqlValue) -> Result<DateTime<Local>> {
         let ts = val.to_timestamp()?;
-        datetime_from_sql(&Local, &ts)
+        if ts.with_tz() {
+            datetime_from_sql(&fixed_offset_from_sql(&ts)?, &ts)
+                .map(|val| val.with_timezone(&Local))
+        } else {
+            datetime_from_sql(&Local, &ts)
+        }
     }
 }
 
@@ -144,7 +154,12 @@ where
 impl FromSql for Date<Utc> {
     fn from_sql(val: &SqlValue) -> Result<Date<Utc>> {
         let ts = val.to_timestamp()?;
-        date_from_sql(&Utc, &ts)
+        if ts.with_tz() {
+            date_from_sql(&fixed_offset_from_sql(&ts)?, &ts)
+                .map(|val| val.with_timezone(&Utc))
+        } else {
+            date_from_sql(&Utc, &ts)
+        }
     }
 }
 
@@ -152,7 +167,12 @@ impl FromSql for Date<Utc> {
 impl FromSql for Date<Local> {
     fn from_sql(val: &SqlValue) -> Result<Date<Local>> {
         let ts = val.to_timestamp()?;
-        date_from_sql(&Local, &ts)
+        if ts.with_tz() {
+            date_from_sql(&fixed_offset_from_sql(&ts)?, &ts)
+                .map(|val| val.with_timezone(&Local))
+        } else {
+            date_from_sql(&Local, &ts)
+        }
     }
 }
 
diff --git a/tests/from_to_sql.rs b/tests/from_to_sql.rs
index 98dafec7..880a393d 100644
--- a/tests/from_to_sql.rs
+++ b/tests/from_to_sql.rs
@@ -887,17 +887,27 @@ mod chrono {
             &dttm
         );
 
-        // TIMESTAMP WITH TIME ZONE -> DateTime<Utc>  TZ is ignored.
-        let dttm = Utc.ymd(2012, 3, 4).and_hms_nano(5, 6, 7, 123456789);
+        // TIMESTAMP WITH TIME ZONE -> DateTime<Utc>  TZ is mapped.
+        let dttm = Utc.ymd(2012, 3, 4).and_hms_nano(4, 6, 7, 123456789);
         test_from_sql!(&conn,
                        "TO_TIMESTAMP_TZ('2012-03-04 05:06:07.123456789 +01:00', 'YYYY-MM-DD HH24:MI:SS.FF9 TZH:TZM')",
                        &OracleType::TimestampTZ(9), &dttm);
 
-        // TIMESTAMP WITH TIME ZONE -> DateTime<Local>  TZ is ignored.
+        // TIMESTAMP WITH TIME ZONE -> DateTime<Local>  TZ is mapped.
         let dttm = Local.ymd(2012, 3, 4).and_hms_nano(5, 6, 7, 123456789);
-        test_from_sql!(&conn,
-                       "TO_TIMESTAMP_TZ('2012-03-04 05:06:07.123456789 +01:00', 'YYYY-MM-DD HH24:MI:SS.FF9 TZH:TZM')",
-                       &OracleType::TimestampTZ(9), &dttm);
+        let tz_offset = dttm.offset().fix().local_minus_utc();
+        let tz_sign = if tz_offset >= 0 { '+' } else { '-' };
+        let tz_hour = tz_offset.abs() / 3600;
+        let tz_min = tz_offset.abs() % 3600 / 60;
+        test_from_sql!(
+            &conn,
+            &format!(
+                "TO_TIMESTAMP_TZ('2012-03-04 05:06:07.123456789 {}{:02}:{:02}', 'YYYY-MM-DD HH24:MI:SS.FF9 TZH:TZM')",
+                tz_sign, tz_hour, tz_min
+            ),
+            &OracleType::TimestampTZ(9),
+            &dttm
+        );
 
         // TIMESTAMP WITH TIME ZONE -> DateTime<Fixed_Utc> TZ is set.
         let dttm = fixed_cet.ymd(2012, 3, 4).and_hms_nano(5, 6, 7, 123456789);
@@ -1015,13 +1025,13 @@ mod chrono {
             &dttm
         );
 
-        // TIMESTAMP WITH TIME ZONE -> Date<Utc>  TZ is ignored.
+        // TIMESTAMP WITH TIME ZONE -> Date<Utc>  TZ is mapped.
         let dttm = Utc.ymd(2012, 3, 4);
         test_from_sql!(&conn,
                        "TO_TIMESTAMP_TZ('2012-03-04 05:06:07.123456789 +01:00', 'YYYY-MM-DD HH24:MI:SS.FF9 TZH:TZM')",
                        &OracleType::TimestampTZ(9), &dttm);
 
-        // TIMESTAMP WITH TIME ZONE -> Date<Local>  TZ is ignored.
+        // TIMESTAMP WITH TIME ZONE -> Date<Local>  TZ is mapped.
         let dttm = Local.ymd(2012, 3, 4);
         test_from_sql!(&conn,
                        "TO_TIMESTAMP_TZ('2012-03-04 05:06:07.123456789 +01:00', 'YYYY-MM-DD HH24:MI:SS.FF9 TZH:TZM')",