From 7ec6b30d98b6116c081dc800710ad04f6e098bd3 Mon Sep 17 00:00:00 2001
From: Paul Dicker <paul@pitdicker.nl>
Date: Sun, 28 May 2023 16:10:02 +0200
Subject: [PATCH] Deny offset when parsing to `NaiveDateTime`

---
 src/format/parsed.rs        |  5 ++++-
 src/naive/datetime/mod.rs   | 15 ++++++++++-----
 src/naive/datetime/tests.rs |  8 ++++----
 src/naive/time/tests.rs     |  4 +---
 4 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/src/format/parsed.rs b/src/format/parsed.rs
index 073ba1f5d2..392708ccfd 100644
--- a/src/format/parsed.rs
+++ b/src/format/parsed.rs
@@ -507,6 +507,9 @@ impl Parsed {
     /// from date and time fields or a single [`timestamp`](#structfield.timestamp) field.
     /// Either way those fields have to be consistent to each other.
     pub fn to_naive_datetime_with_offset(&self, offset: i32) -> ParseResult<NaiveDateTime> {
+        if self.offset.is_some() {
+            return Err(BAD_FORMAT);
+        }
         self.to_naive_datetime_with_offset_inner(offset, true)
     }
 
@@ -650,7 +653,7 @@ impl Parsed {
 
         // `guessed_offset` should be correct when `self.timestamp` is given.
         // it will be 0 otherwise, but this is fine as the algorithm ignores offset for that case.
-        let datetime = self.to_naive_datetime_with_offset(guessed_offset)?;
+        let datetime = self.to_naive_datetime_with_offset_inner(guessed_offset, false)?;
         match tz.from_local_datetime(&datetime) {
             LocalResult::None => Err(IMPOSSIBLE),
             LocalResult::Single(t) => {
diff --git a/src/naive/datetime/mod.rs b/src/naive/datetime/mod.rs
index af5066aae8..2a4ed35826 100644
--- a/src/naive/datetime/mod.rs
+++ b/src/naive/datetime/mod.rs
@@ -240,13 +240,18 @@ impl NaiveDateTime {
     ///            Ok(NaiveDate::from_ymd_opt(2015, 9, 5).unwrap().and_hms_micro_opt(13, 23, 45, 678_900).unwrap()));
     /// ```
     ///
-    /// Offset is ignored for the purpose of parsing.
+    /// An included offset will return an error, parse to a `DateTime<FixedOffset>` first.
     ///
     /// ```
-    /// # use chrono::{NaiveDateTime, NaiveDate};
-    /// # let parse_from_str = NaiveDateTime::parse_from_str;
-    /// assert_eq!(parse_from_str("2014-5-17T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z"),
-    ///            Ok(NaiveDate::from_ymd_opt(2014, 5, 17).unwrap().and_hms_opt(12, 34, 56).unwrap()));
+    /// use chrono::{DateTime, NaiveDateTime, NaiveDate, FixedOffset};
+    /// use chrono::format::ParseErrorKind;
+    ///
+    /// let r = NaiveDateTime::parse_from_str("2014-5-17T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z");
+    /// assert_eq!(r.unwrap_err().kind(), ParseErrorKind::BadFormat);
+    /// let dt =
+    ///     DateTime::<FixedOffset>::parse_from_str("2014-5-17T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z");
+    /// assert_eq!(dt.unwrap().naive_local(),
+    ///            NaiveDate::from_ymd_opt(2014, 5, 17).unwrap().and_hms_opt(12, 34, 56).unwrap());
     /// ```
     ///
     /// [Leap seconds](./struct.NaiveTime.html#leap-second-handling) are correctly handled by
diff --git a/src/naive/datetime/tests.rs b/src/naive/datetime/tests.rs
index 96ff3b15b5..ecb1939a0e 100644
--- a/src/naive/datetime/tests.rs
+++ b/src/naive/datetime/tests.rs
@@ -281,10 +281,6 @@ fn test_datetime_parse_from_str() {
     let ymdhmsn = |y, m, d, h, n, s, nano| {
         NaiveDate::from_ymd_opt(y, m, d).unwrap().and_hms_nano_opt(h, n, s, nano).unwrap()
     };
-    assert_eq!(
-        NaiveDateTime::parse_from_str("2014-5-7T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z"),
-        Ok(ymdhms(2014, 5, 7, 12, 34, 56))
-    ); // ignore offset
     assert!(
         // intermixed whitespace
         NaiveDateTime::parse_from_str("2015-W06-1 000000", "%G-W%V-%u%H%M%S").is_err()
@@ -324,6 +320,10 @@ fn test_datetime_parse_from_str() {
         NaiveDateTime::parse_from_str("1437742189.918273645", "%s%.9f"),
         Ok(ymdhmsn(2015, 7, 24, 12, 49, 49, 918273645))
     );
+
+    assert!(
+        NaiveDateTime::parse_from_str("2014-5-7T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z").is_err()
+    );
 }
 
 #[test]
diff --git a/src/naive/time/tests.rs b/src/naive/time/tests.rs
index a26ced32bc..0b3450cef8 100644
--- a/src/naive/time/tests.rs
+++ b/src/naive/time/tests.rs
@@ -342,9 +342,7 @@ fn test_time_parse_from_str() {
 
     assert!(NaiveTime::parse_from_str("2014-5-7T12:34:56", "%Y-%m-%dT%H:%M:%S").is_err());
     assert!(NaiveTime::parse_from_str("12:34:56+09:30", "%%H:%M:%S%z").is_err());
-    assert!(
-        NaiveTime::parse_from_str("2014-5-7T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z").is_err()
-    );
+    assert!(NaiveTime::parse_from_str("2014-5-7T12:34:56+09:30", "%Y-%m-%dT%H:%M:%S%z").is_err());
 }
 
 #[test]