Speculative fix and test for crash

Add a check to SetICUDefault() and fall back to en-US when an incoming
locale id fails to create a valid icu::locale instance.

Roll ICU to b971435d43 to pick up an upstream fix.

icu::Locale::setDefault() can fail when an invalid/too long locale id is
passed. It appears that this might happen when the locale id comes from
GetOverrideLocale() on iOS.

A test added is similar to what the upstream added in the upstream fix (
http://bugs.icu-project.org/trac/changeset/40267 ) which was cherry-picked in
https://chromium-review.googlesource.com/c/574935/ .


BUG=chromium:734093
TEST=base_unittests --gtest_filter=SetICU*

Change-Id: If8d3522b23a257466ca3c31b66089cb415fec3a2
Reviewed-on: https://chromium-review.googlesource.com/574936Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Jungshik Shin <jshin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487533}

DEPS

@@ -157,7 +157,7 @@ deps = {
     Var('chromium_git') + '/external/github.com/google/googletest.git' + '@' + '42bc671f47b122fad36db5eccbc06868afdf7862',
 
   'src/third_party/icu':
-    Var('chromium_git') + '/chromium/deps/icu.git' + '@' + 'dfa798fe694702b43a3debc3290761f22b1acaf8',
+    Var('chromium_git') + '/chromium/deps/icu.git' + '@' + 'b971435d43d012e9c49ef5e99c0c3047640d53be',
 
   'src/third_party/hunspell_dictionaries':
     Var('chromium_git') + '/chromium/deps/hunspell_dictionaries.git' + '@' + 'dc6e7c25bf47cbfb466e0701fd2728b4a12e79d5',

base/i18n/rtl.cc

@@ -156,12 +156,14 @@ std::string ICULocaleName(const std::string& locale_string) {
 void SetICUDefaultLocale(const std::string& locale_string) {
   icu::Locale locale(ICULocaleName(locale_string).c_str());
   UErrorCode error_code = U_ZERO_ERROR;
-  icu::Locale::setDefault(locale, error_code);
-  // This return value is actually bogus because Locale object is
-  // an ID and setDefault seems to always succeed (regardless of the
-  // presence of actual locale data). However,
-  // it does not hurt to have it as a sanity check.
-  DCHECK(U_SUCCESS(error_code));
+  const char* lang = locale.getLanguage();
+  if (lang != nullptr && *lang != '\0') {
+    icu::Locale::setDefault(locale, error_code);
+  } else {
+    LOG(ERROR) << "Failed to set the ICU default locale to " << locale_string
+               << ". Falling back to en-US.";
+    icu::Locale::setDefault(icu::Locale::getUS(), error_code);
+  }
   g_icu_text_direction = UNKNOWN_DIRECTION;
 }
 

base/i18n/rtl_unittest.cc

@@ -17,6 +17,7 @@
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
+#include "third_party/icu/source/common/unicode/locid.h"
 #include "third_party/icu/source/i18n/unicode/usearch.h"
 
 namespace base {
@@ -467,5 +468,19 @@ TEST_F(RTLTest, UnadjustStringForLocaleDirection) {
   EXPECT_EQ(was_rtl, IsRTL());
 }
 
+class SetICULocaleTest : public PlatformTest {};
+
+TEST_F(SetICULocaleTest, OverlongLocaleId) {
+  test::ScopedRestoreICUDefaultLocale restore_locale;
+  std::string id("fr-ca-x-foo");
+  while (id.length() < 152)
+    id.append("-x-foo");
+  SetICUDefaultLocale(id);
+  EXPECT_STRNE("en_US", icu::Locale::getDefault().getName());
+  id.append("zzz");
+  SetICUDefaultLocale(id);
+  EXPECT_STREQ("en_US", icu::Locale::getDefault().getName());
+}
+
 }  // namespace i18n
 }  // namespace base