Fix digit grouping: m_grouping_top doesn't mean what I thought it did

I'd previously understood CLDR's minimumGroupingDigits to mean the
most significant group must have that many digits. It turns out to
mean only that the first grouping separator doesn't get added unless
the more significant group has this many. Once we have one separator,
more can be added that do isolate a single digit.

In the process, I discover some of the prior arithmetic is incorrect;
it is now fixed. Added some basic testing, amended some existing
tests. In the process, fixed naming of some double validator tests.

Pick-to: 6.6 6.5
Fixes: QTBUG-115740
Change-Id: Ia6ce011ba72e72428b015ca22b97d815ebf751b2
Reviewed-by: Ievgenii Meshcheriakov <ievgenii.meshcheriakov@qt.io>

1 files changed, 89 insertions, 1 deletions

diff --git a/tests/auto/corelib/text/qlocale/tst_qlocale.cpp b/tests/auto/corelib/text/qlocale/tst_qlocale.cpp
index 04fae3898b..ad491b6854 100644
--- a/tests/auto/corelib/text/qlocale/tst_qlocale.cpp
+++ b/tests/auto/corelib/text/qlocale/tst_qlocale.cpp
@@ -134,6 +134,8 @@ private slots:
     void systemLocaleDayAndMonthNames();
 #endif
 
+    void numberGrouping_data();
+    void numberGrouping();
     void numberGroupingIndia();
     void numberFormatChakma();
 
@@ -1229,7 +1231,9 @@ void tst_QLocale::doubleToString_data()
     QTest::newRow("de_DE 1245678900 g -")  << QString("de_DE") << QString("1.245.678.900") << 12456789e2 << 'g' << shortest;
     QTest::newRow("de_DE 12456789100 g -") << QString("de_DE") << QString("12.456.789.100") << 124567891e2 << 'g' << shortest;
     QTest::newRow("de_DE 12456789000 g -") << QString("de_DE") << QString("1,2456789E+10")  << 12456789e3 << 'g' << shortest;
-    QTest::newRow("de_DE 120000 g -")  << QString("de_DE") << QString("120.000") << 12e4 << 'g' << shortest;
+    QTest::newRow("de_DE 12000 g -")
+        << QString("de_DE") << QString("12.000") << 12e3 << 'g' << shortest;
+    // 12e4 has "120.000" and "1.2E+05" of equal length; which shortest picks is unspecified.
     QTest::newRow("de_DE 1200000 g -") << QString("de_DE") << QString("1,2E+06") << 12e5 << 'g' << shortest;
     QTest::newRow("de_DE 1000 g -")  << QString("de_DE") << QString("1.000") << 1e3 << 'g' << shortest;
     QTest::newRow("de_DE 10000 g -") << QString("de_DE") << QString("1E+04") << 1e4 << 'g' << shortest;
@@ -4056,6 +4060,90 @@ void tst_QLocale::systemLocaleDayAndMonthNames()
 
 #endif // QT_NO_SYSTEMLOCALE
 
+void tst_QLocale::numberGrouping_data()
+{
+    QTest::addColumn<QLocale>("locale");
+    QTest::addColumn<int>("number");
+    QTest::addColumn<QString>("string");
+    // Number options set here are expected to be default, but set for the
+    // avoidance of uncertainty or susceptibility to changed defaults.
+
+    QLocale c(QLocale::C); // English-style, without separators.
+    c.setNumberOptions(c.numberOptions() | QLocale::OmitGroupSeparator);
+    QTest::newRow("c:1") << c << 1 << u"1"_s;
+    QTest::newRow("c:12") << c << 12 << u"12"_s;
+    QTest::newRow("c:123") << c << 123 << u"123"_s;
+    QTest::newRow("c:1234") << c << 1234 << u"1234"_s;
+    QTest::newRow("c:12345") << c << 12345 << u"12345"_s;
+    QTest::newRow("c:123456") << c << 123456 << u"123456"_s;
+    QTest::newRow("c:1234567") << c << 1234567 << u"1234567"_s;
+    QTest::newRow("c:12345678") << c << 12345678 << u"12345678"_s;
+    QTest::newRow("c:123456789") << c << 123456789 << u"123456789"_s;
+    QTest::newRow("c:1234567890") << c << 1234567890 << u"1234567890"_s;
+
+    QLocale en(QLocale::English); // English-style, with separators:
+    en.setNumberOptions(en.numberOptions() & ~QLocale::OmitGroupSeparator);
+    QTest::newRow("en:1") << en << 1 << u"1"_s;
+    QTest::newRow("en:12") << en << 12 << u"12"_s;
+    QTest::newRow("en:123") << en << 123 << u"123"_s;
+    QTest::newRow("en:1,234") << en << 1234 << u"1,234"_s;
+    QTest::newRow("en:12,345") << en << 12345 << u"12,345"_s;
+    QTest::newRow("en:123,456") << en << 123456 << u"123,456"_s;
+    QTest::newRow("en:1,234,567") << en << 1234567 << u"1,234,567"_s;
+    QTest::newRow("en:12,345,678") << en << 12345678 << u"12,345,678"_s;
+    QTest::newRow("en:123,456,789") << en << 123456789 << u"123,456,789"_s;
+    QTest::newRow("en:1,234,567,890") << en << 1234567890 << u"1,234,567,890"_s;
+
+    QLocale es(QLocale::Spanish); // Spanish-style, with separators
+    es.setNumberOptions(es.numberOptions() & ~QLocale::OmitGroupSeparator);
+    QTest::newRow("es:1") << es << 1 << u"1"_s;
+    QTest::newRow("es:12") << es << 12 << u"12"_s;
+    QTest::newRow("es:123") << es << 123 << u"123"_s;
+    // First split doesn't happen unless first group has at least two digits:
+    QTest::newRow("es:1234") << es << 1234 << u"1234"_s;
+    QTest::newRow("es:12.345") << es << 12345 << u"12.345"_s;
+    QTest::newRow("es:123.456") << es << 123456 << u"123.456"_s;
+    // Later splits aren't limited to two digits (QTBUG-115740):
+    QTest::newRow("es:1.234.567") << es << 1234567 << u"1.234.567"_s;
+    QTest::newRow("es:12.345.678") << es << 12345678 << u"12.345.678"_s;
+    QTest::newRow("es:123.456.789") << es << 123456789 << u"123.456.789"_s;
+    QTest::newRow("es:1.234.567.890") << es << 1234567890 << u"1.234.567.890"_s;
+
+    QLocale hi(QLocale::Hindi, QLocale::India);
+    hi.setNumberOptions(hi.numberOptions() & ~QLocale::OmitGroupSeparator);
+    QTest::newRow("hi:1") << hi << 1 << u"1"_s;
+    QTest::newRow("hi:12") << hi << 12 << u"12"_s;
+    QTest::newRow("hi:123") << hi << 123 << u"123"_s;
+    QTest::newRow("hi:1,234") << hi << 1234 << u"1,234"_s;
+    QTest::newRow("hi:12,345") << hi << 12345 << u"12,345"_s;
+    QTest::newRow("hi:1,23,456") << hi << 123456 << u"1,23,456"_s;
+    QTest::newRow("hi:12,34,567") << hi << 1234567 << u"12,34,567"_s;
+    QTest::newRow("hi:1,23,45,678") << hi << 12345678 << u"1,23,45,678"_s;
+    QTest::newRow("hi:12,34,56,789") << hi << 123456789 << u"12,34,56,789"_s;
+    QTest::newRow("hi:1,23,45,67,890") << hi << 1234567890 << u"1,23,45,67,890"_s;
+}
+
+void tst_QLocale::numberGrouping()
+{
+    QFETCH(const QLocale, locale);
+    QFETCH(const int, number);
+    QFETCH(const QString, string);
+
+    QCOMPARE(locale.toString(number), string);
+    QLocale sys = QLocale::system();
+    if (sys.language() == locale.language()
+            && sys.script() == locale.script()
+            && sys.territory() == locale.territory()) {
+        sys.setNumberOptions(locale.numberOptions());
+
+        QCOMPARE(sys.toString(number), string);
+        if (QLocale() == sys) { // This normally should be the case.
+            QCOMPARE(u"%L1"_s.arg(number), string);
+            QCOMPARE(u"%L1"_s.arg(double(number), 0, 'f', 0), string);
+        }
+    }
+}
+
 void tst_QLocale::numberGroupingIndia()
 {
     const QLocale indian(QLocale::Hindi, QLocale::India);