Issue #1969 - Implement Intl.RelativeTimeFormat.

Based on Mozilla bugs 1270140, 1504656, 1483545, and 1504334.
Took note of Mozilla bug 1379222 which changed GetPrototypeFromCallableConstructor
 to GetPrototypeFromBuiltinConstructor.
There are many other changes I did myself since the initial implementation by
 Mozilla wouldn't work with this codebase.

4 files changed, 63 insertions, 9 deletions

diff --git a/intl/icu-patches/bug-1504656-relativetimeformat-plural-other-fallback.diff b/intl/icu-patches/bug-1504656-relativetimeformat-plural-other-fallback.diff
new file mode 100644
index 0000000000..060ea5c0bf
--- /dev/null
+++ b/intl/icu-patches/bug-1504656-relativetimeformat-plural-other-fallback.diff
@@ -0,0 +1,45 @@
+Workaround for https://unicode-org.atlassian.net/browse/ICU-20253
+
+https://bugzilla.mozilla.org/show_bug.cgi?id=1504656
+
+diff --git a/intl/icu/source/i18n/reldatefmt.cpp b/intl/icu/source/i18n/reldatefmt.cpp
+--- a/intl/icu/source/i18n/reldatefmt.cpp
++++ b/intl/icu/source/i18n/reldatefmt.cpp
+@@ -157,24 +157,30 @@ const UnicodeString& RelativeDateTimeCac
+  }
+ 
+  // Use fallback cache for SimpleFormatter relativeUnits.
+  const SimpleFormatter* RelativeDateTimeCacheData::getRelativeDateTimeUnitFormatter(
+         int32_t fStyle,
+         URelativeDateTimeUnit unit,
+         int32_t pastFutureIndex,
+         int32_t pluralUnit) const {
+-    int32_t style = fStyle;
+-    do {
+-        if (relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit] != nullptr) {
+-            return relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit];
++    while (true) {
++        int32_t style = fStyle;
++        do {
++            if (relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit] != nullptr) {
++                return relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit];
++            }
++            style = fallBackCache[style];
++        } while (style != -1);
++
++        if (pluralUnit == StandardPlural::OTHER) {
++            return nullptr;  // No formatter found.
+         }
+-        style = fallBackCache[style];
+-    } while (style != -1);
+-    return nullptr;  // No formatter found.
++        pluralUnit = StandardPlural::OTHER;
++    }
+  }
+ 
+ static UBool getStringWithFallback(
+         const UResourceBundle *resource,
+         const char *key,
+         UnicodeString &result,
+         UErrorCode &status) {
+     int32_t len = 0;
diff --git a/intl/icu/source/i18n/reldatefmt.cpp b/intl/icu/source/i18n/reldatefmt.cpp
index 1a4da0f0b9..85637cb456 100644
--- a/intl/icu/source/i18n/reldatefmt.cpp
+++ b/intl/icu/source/i18n/reldatefmt.cpp
@@ -162,14 +162,20 @@ const UnicodeString& RelativeDateTimeCacheData::getAbsoluteUnitString(
         URelativeDateTimeUnit unit,
         int32_t pastFutureIndex,
         int32_t pluralUnit) const {
-    int32_t style = fStyle;
-    do {
-        if (relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit] != nullptr) {
-            return relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit];
+    while (true) {
+        int32_t style = fStyle;
+        do {
+            if (relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit] != nullptr) {
+                return relativeUnitsFormatters[style][unit][pastFutureIndex][pluralUnit];
+            }
+            style = fallBackCache[style];
+        } while (style != -1);
+
+        if (pluralUnit == StandardPlural::OTHER) {
+            return nullptr;  // No formatter found.
         }
-        style = fallBackCache[style];
-    } while (style != -1);
-    return nullptr;  // No formatter found.
+        pluralUnit = StandardPlural::OTHER;
+    }
  }
 
 static UBool getStringWithFallback(
diff --git a/intl/patch-icu.sh b/intl/patch-icu.sh
index 4c8cd89cba..a8e9977ea5 100644..100755
--- a/intl/patch-icu.sh
+++ b/intl/patch-icu.sh
@@ -21,7 +21,9 @@ for patch in \
  suppress-warnings.diff \
  bug-1172609-timezone-recreateDefault.diff \
  bug-1198952-workaround-make-3.82-bug.diff \
+ bug-1504656-relativetimeformat-plural-other-fallback.diff \
 ; do
   echo "Applying local patch $patch"
   patch -d ${icu_dir}/../../ -p1 --no-backup-if-mismatch < ${icu_dir}/../icu-patches/$patch
 done
+
diff --git a/intl/update-icu.sh b/intl/update-icu.sh
index 7e4c833c7b..ae22076ab3 100755
--- a/intl/update-icu.sh
+++ b/intl/update-icu.sh
@@ -7,11 +7,11 @@ set -e
 
 # Update to an ICU release:
 #   Usage: update-icu.sh <URL of ICU GIT> <release tag name>
-#   E.g., for ICU 63.2: update-icu.sh https://github.com/unicode-org/icu.git release-63-2
+#   E.g., for ICU 62.2: update-icu.sh https://github.com/unicode-org/icu.git release-62-2
 #
 # Update to an ICU maintenance branch:
 #   Usage: update-icu.sh <URL of ICU GIT> <maintenance name>
-#   E.g., for ICU 63.2: update-icu.sh https://github.com/unicode-org/icu.git maint/maint-63
+#   E.g., for ICU 62.2: update-icu.sh https://github.com/unicode-org/icu.git maint/maint-62
 
 if [ $# -lt 2 ]; then
   echo "Usage: update-icu.sh <URL of ICU GIT> <release tag name>"
@@ -86,6 +86,7 @@ for patch in \
  suppress-warnings.diff \
  bug-1172609-timezone-recreateDefault.diff \
  bug-1198952-workaround-make-3.82-bug.diff \
+ bug-1504656-relativetimeformat-plural-other-fallback.diff \
 ; do
   echo "Applying local patch $patch"
   patch -d ${icu_dir}/../../ -p1 --no-backup-if-mismatch < ${icu_dir}/../icu-patches/$patch