From 4d75ddd58146e7ef20c6f3f9516b437cd186f6d4 Mon Sep 17 00:00:00 2001
From: Paul Dicker <paul@pitdicker.nl>
Date: Sun, 11 Jun 2023 08:52:31 +0200
Subject: [PATCH] Use `parse_rfc3339` directly in
 `DateTime::parse_from_rfc3339`

---
 src/datetime/mod.rs | 11 +++++++----
 src/format/mod.rs   |  3 ++-
 src/format/parse.rs | 10 ++--------
 3 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/datetime/mod.rs b/src/datetime/mod.rs
index bf9c16ad5d..23586cd4d2 100644
--- a/src/datetime/mod.rs
+++ b/src/datetime/mod.rs
@@ -22,8 +22,9 @@ use std::time::{SystemTime, UNIX_EPOCH};
 use crate::format::DelayedFormat;
 #[cfg(feature = "unstable-locales")]
 use crate::format::Locale;
-use crate::format::{parse, parse_and_remainder, ParseError, ParseResult, Parsed, StrftimeItems};
-use crate::format::{Fixed, Item};
+use crate::format::{parse, parse_and_remainder, parse_rfc3339};
+use crate::format::{Fixed, Item, TOO_LONG};
+use crate::format::{ParseError, ParseResult, Parsed, StrftimeItems};
 use crate::naive::{Days, IsoWeek, NaiveDate, NaiveDateTime, NaiveTime};
 #[cfg(feature = "clock")]
 use crate::offset::Local;
@@ -631,9 +632,11 @@ impl DateTime<FixedOffset> {
     /// also simultaneously valid RFC 3339 values, but not all RFC 3339 values are valid ISO 8601
     /// values (or the other way around).
     pub fn parse_from_rfc3339(s: &str) -> ParseResult<DateTime<FixedOffset>> {
-        const ITEMS: &[Item<'static>] = &[Item::Fixed(Fixed::RFC3339)];
         let mut parsed = Parsed::new();
-        parse(&mut parsed, s, ITEMS.iter())?;
+        let (s, _) = parse_rfc3339(&mut parsed, s)?;
+        if !s.is_empty() {
+            return Err(TOO_LONG);
+        }
         parsed.to_datetime()
     }
 
diff --git a/src/format/mod.rs b/src/format/mod.rs
index 7c9c3b7dd0..d077256641 100644
--- a/src/format/mod.rs
+++ b/src/format/mod.rs
@@ -56,6 +56,7 @@ use crate::{Month, ParseMonthError, ParseWeekdayError, Weekday};
 #[cfg(feature = "unstable-locales")]
 pub(crate) mod locales;
 
+pub(crate) use parse::parse_rfc3339;
 pub use parse::{parse, parse_and_remainder};
 pub use parsed::Parsed;
 /// L10n locales.
@@ -425,7 +426,7 @@ const IMPOSSIBLE: ParseError = ParseError(ParseErrorKind::Impossible);
 const NOT_ENOUGH: ParseError = ParseError(ParseErrorKind::NotEnough);
 const INVALID: ParseError = ParseError(ParseErrorKind::Invalid);
 const TOO_SHORT: ParseError = ParseError(ParseErrorKind::TooShort);
-const TOO_LONG: ParseError = ParseError(ParseErrorKind::TooLong);
+pub(crate) const TOO_LONG: ParseError = ParseError(ParseErrorKind::TooLong);
 const BAD_FORMAT: ParseError = ParseError(ParseErrorKind::BadFormat);
 
 #[cfg(any(feature = "alloc", feature = "std", test))]
diff --git a/src/format/parse.rs b/src/format/parse.rs
index ae31d6a1df..d5fa162450 100644
--- a/src/format/parse.rs
+++ b/src/format/parse.rs
@@ -157,7 +157,7 @@ fn parse_rfc2822<'a>(parsed: &mut Parsed, mut s: &'a str) -> ParseResult<(&'a st
     Ok((s, ()))
 }
 
-fn parse_rfc3339<'a>(parsed: &mut Parsed, mut s: &'a str) -> ParseResult<(&'a str, ())> {
+pub(crate) fn parse_rfc3339<'a>(parsed: &mut Parsed, mut s: &'a str) -> ParseResult<(&'a str, ())> {
     macro_rules! try_consume {
         ($e:expr) => {{
             let (s_, v) = $e?;
@@ -1491,19 +1491,13 @@ fn test_rfc3339() {
         ("2015-01-20T00:00:1-08:00", Err(INVALID)),   // missing complete S
     ];
 
-    fn rfc3339_to_datetime(date: &str) -> ParseResult<DateTime<FixedOffset>> {
-        let mut parsed = Parsed::new();
-        parse(&mut parsed, date, [Item::Fixed(Fixed::RFC3339)].iter())?;
-        parsed.to_datetime()
-    }
-
     fn fmt_rfc3339_datetime(dt: DateTime<FixedOffset>) -> String {
         dt.format_with_items([Item::Fixed(Fixed::RFC3339)].iter()).to_string()
     }
 
     // Test against test data above
     for &(date, checkdate) in testdates.iter() {
-        let d = rfc3339_to_datetime(date); // parse a date
+        let d = DateTime::<FixedOffset>::parse_from_rfc3339(date);
         let dt = match d {
             // did we get a value?
             Ok(dt) => Ok(fmt_rfc3339_datetime(dt)), // yes, go on