Fix crash in creating NumberFormat

setUnicodeKeywordValue doesn't remove unrelated keyword/value pairs
when the locale is too long, which causes NumberFormat to fail when
calling createInstance. Fix this by using LocaleBuilder to add keyword/value
into a new locale instead of removing the keyword.

Also see https://unicode-org.atlassian.net/browse/ICU-20862

Bug: chromium:1012579
Change-Id: I0f664f60dad8fe786443c8ca8b21ea43323cbf49
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1855586Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64253}

src/objects/intl-objects.cc

@@ -33,6 +33,7 @@
 #include "unicode/datefmt.h"
 #include "unicode/decimfmt.h"
 #include "unicode/formattedvalue.h"
+#include "unicode/localebuilder.h"
 #include "unicode/locid.h"
 #include "unicode/normalizer2.h"
 #include "unicode/numberformatter.h"
@@ -1611,6 +1612,8 @@ std::map<std::string, std::string> LookupAndValidateUnicodeExtensions(
   std::map<std::string, std::string> extensions;
 
   UErrorCode status = U_ZERO_ERROR;
+  icu::LocaleBuilder builder;
+  builder.setLocale(*icu_locale).clearExtensions();
   std::unique_ptr<icu::StringEnumeration> keywords(
       icu_locale->createKeywords(status));
   if (U_FAILURE(status)) return extensions;
@@ -1672,20 +1675,14 @@ std::map<std::string, std::string> LookupAndValidateUnicodeExtensions(
       if (is_valid_value) {
         extensions.insert(
             std::pair<std::string, std::string>(bcp47_key, bcp47_value));
-        continue;
+        builder.setUnicodeLocaleKeyword(bcp47_key, bcp47_value);
       }
     }
-    status = U_ZERO_ERROR;
-    icu_locale->setUnicodeKeywordValue(
-        bcp47_key == nullptr ? keyword : bcp47_key, nullptr, status);
-    // Ignore failures in ICU and skip to the next keyword.
-    //
-    // This is fine.™
-    if (U_FAILURE(status)) {
-      status = U_ZERO_ERROR;
-    }
   }
 
+  status = U_ZERO_ERROR;
+  *icu_locale = builder.build(status);
+
   return extensions;
 }
 

test/intl/regress-1012579.js

+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+let longLocale = 'de-u-cf-cu-em-kk-kr-ks-kv-lb-lw-ms-nu-rg-sd-ss-tz';
+rtf = new Intl.RelativeTimeFormat(longLocale);