Don't model Morocco as standard/daylight

Author: robertbastian

provider/source/data/debug/timezone/metazone/periods/v1.json

@@ -479,30 +479,30 @@ impl TzdbCache {
                     }
                 }
 
-                // Morocco doesn't have have rearguard data in the text file, so we have to replicate the transform from
-                // ziguard.awk: https://github.com/eggert/tz/blob/271a5784a59e454b659d85948b5e65c17c11516a/ziguard.awk#L261-L299
-                for line in lines.iter_mut() {
-                    if line.starts_with("Rule\tMorocco") {
-                        let mut parts = line.split('\t').skip(2);
-                        let from = parts.next().unwrap();
-                        let to = parts.next().unwrap();
-                        let _type = parts.next().unwrap();
-                        let month = parts.next().unwrap();
-                        let _day = parts.next().unwrap();
-                        let _time = parts.next().unwrap();
-                        let save = parts.next().unwrap();
-                        if to == "2018" && month == "Oct" {
-                            *line = line.replace("2018", "2017");
-                        } else if from.parse::<i32>().unwrap() >= 2019 {
-                            if save.trim() == "0" {
-                                *line = line.replace("\t0\t", "\t1:00\t");
-                            } else {
-                                *line = line.replace("\t-1:00\t", "\t0\t");
-                            }
-                        }
-                    }
-                    *line = line.replace("1:00\tMorocco\t%z", "0:00\tMorocco\t+00/+01");
-                }
+                // // Morocco doesn't have have rearguard data in the text file, so we have to replicate the transform from
+                // // ziguard.awk: https://github.com/eggert/tz/blob/271a5784a59e454b659d85948b5e65c17c11516a/ziguard.awk#L261-L299
+                // for line in lines.iter_mut() {
+                //     if line.starts_with("Rule\tMorocco") {
+                //         let mut parts = line.split('\t').skip(2);
+                //         let from = parts.next().unwrap();
+                //         let to = parts.next().unwrap();
+                //         let _type = parts.next().unwrap();
+                //         let month = parts.next().unwrap();
+                //         let _day = parts.next().unwrap();
+                //         let _time = parts.next().unwrap();
+                //         let save = parts.next().unwrap();
+                //         if to == "2018" && month == "Oct" {
+                //             *line = line.replace("2018", "2017");
+                //         } else if from.parse::<i32>().unwrap() >= 2019 {
+                //             if save.trim() == "0" {
+                //                 *line = line.replace("\t0\t", "\t1:00\t");
+                //             } else {
+                //                 *line = line.replace("\t-1:00\t", "\t0\t");
+                //             }
+                //         }
+                //     }
+                //     *line = line.replace("1:00\tMorocco\t%z", "0:00\tMorocco\t+00/+01");
+                // }
 
                 #[allow(deprecated)] // no alternative?!
                 let parser = LineParser::new();

provider/source/data/debug/timezone/variants/offsets/v1.json

@@ -300,6 +300,17 @@ impl SourceDataProvider {
                                 .flatten()
                                 .collect::<Vec<_>>();
 
+                            if iana == "Africa/Casablanca" || iana == "Africa/El_Aaiun" {
+                                periods.push((
+                                    bcp47,
+                                    DateTime {
+                                        date: Date::try_new_iso(2018, 12, 28).unwrap(),
+                                        time: Time::try_new(2, 0, 0, 0).unwrap(),
+                                    },
+                                    NichedOption(meta_zone_id_data.get("Europe_Central").copied()),
+                                ));
+                            }
+
                             let mut i = 0;
                             while i < periods.len() {
                                 if i + 1 < periods.len() && periods[i].1 == periods[i + 1].1 {
@@ -346,12 +357,20 @@ impl SourceDataProvider {
                             data: &mut Vec<(ZoneNameTimestamp, VariantOffsets)>,
                             end_time: ZoneNameTimestamp,
                             mut utc_offset: i64,
-                            dst_offset_relative: i64,
+                            mut dst_offset_relative: i64,
                         ) {
                             // Africa/Monrovia used -00:44:30 pre-1972. We cannot represent this, so we set it to -00:45
                             if utc_offset == -2670 {
                                 utc_offset = -2700
                             }
+                            // Morocco's Ramadan time is modeled as a negative DST offset. We don't support time zone variants
+                            // other than standard and daylight (because CLDR doesn't have patterns for "{0} Ramadan Time"),
+                            // so we ignore the possibility of this offset.
+                            // Clients using `infer_variant()` will see a fallback to a localized UTC offset, which is way
+                            // less ambiguous than either Morocco Standard Time or Morocco Daylight time.
+                            if dst_offset_relative == -3600 {
+                                dst_offset_relative = 0;
+                            }
 
                             data.push((
                                 end_time,