QString/QByteArray::number(double): Test big numbers

Exhausts the entire buffer which double-conversion is left to work with.
Also has a large amount of precision, which apparently we need to store
temporarily.

Task-number: QTBUG-88484
Change-Id: I87e8c323676465f1b8695e086020df1240d0d0d7
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp

@@ -1304,12 +1304,18 @@ void tst_QByteArray::number_double_data()
     // This function is implemented in ../shared/test_number_shared.h
     add_number_double_shared_data([](NumberDoubleTestData datum) {
         QByteArray ba(datum.expected.data(), datum.expected.size());
-        QTest::addRow("%s, format '%c', precision %d", ba.data(), datum.f, datum.p)
+        const char *title = !datum.optTitle.isEmpty() ? datum.optTitle.data() : ba.data();
+        QTest::addRow("%s, format '%c', precision %d", title, datum.f, datum.p)
                 << datum.d << datum.f << datum.p << ba;
         if (datum.f != 'f') { // Also test uppercase format
             datum.f = toupper(datum.f);
             QByteArray upper = ba.toUpper();
-            QTest::addRow("%s, format '%c', precision %d", upper.data(), datum.f, datum.p)
+            QByteArray upperTitle = QByteArray(title);
+            if (!datum.optTitle.isEmpty())
+                upperTitle += ", uppercase";
+            else
+                upperTitle = upperTitle.toUpper();
+            QTest::addRow("%s, format '%c', precision %d", upperTitle.data(), datum.f, datum.p)
                     << datum.d << datum.f << datum.p << upper;
         }
     });

tests/auto/corelib/text/qstring/tst_qstring.cpp

@@ -5210,11 +5210,18 @@ void tst_QString::number_double_data()
 
     // This function is implemented in ../shared/test_number_shared.h
     add_number_double_shared_data([](NumberDoubleTestData datum) {
-        QTest::addRow("%s, format '%c', precision %d", datum.expected.data(), datum.f, datum.p)
+        const char *title =
+                !datum.optTitle.isEmpty() ? datum.optTitle.data() : datum.expected.data();
+        QTest::addRow("%s, format '%c', precision %d", title, datum.f, datum.p)
                 << datum.d << datum.f << datum.p << datum.expected.toString();
         if (datum.f != 'f') { // Also test uppercase format
             datum.f = toupper(datum.f);
             QString upper = datum.expected.toString().toUpper();
+            QString upperTitle = QString::fromLatin1(title);
+            if (!datum.optTitle.isEmpty())
+                upperTitle += ", uppercase";
+            else
+                upperTitle = upperTitle.toUpper();
             QTest::addRow("%s, format '%c', precision %d", qPrintable(upper), datum.f, datum.p)
                     << datum.d << datum.f << datum.p << upper;
         }

tests/auto/corelib/text/shared/test_number_shared.h

@@ -36,6 +36,7 @@ struct NumberDoubleTestData
     char f;
     int p;
     QLatin1String expected;
+    QLatin1String optTitle = {}; // optional
 };
 
 template<typename Fun>
@@ -55,6 +56,31 @@ inline void add_number_double_shared_data(Fun addTestRowFunction)
         { -100000, 'f', 15, QLatin1String("-100000.000000000000000") },
         { 0.5 + qSqrt(1.25), 'f', 15, QLatin1String("1.618033988749895") },
         { 0.5 + qSqrt(1.25), 'e', 15, QLatin1String("1.618033988749895e+00") },
+        { 1.7976931348623157e+308, 'f', 120,
+          QLatin1String(
+                  "17976931348623157081452742373170435679807056752584499659891747680315726078002853"
+                  "87605895586327668781715404589535143824642343213268894641827684675467035375169860"
+                  "49910576551282076245490090389328944075868508455133942304583236903222948165808559"
+                  "332123348274797826204144723168738177180919299881250404026184124858368."
+                  "00000000000000000000000000000000000000000000000000000000000000000000000000000000"
+                  "0000000000000000000000000000000000000000"),
+          QLatin1String("Big number, high precision") },
+        { 1.0, 'f', 350,
+          QLatin1String(
+                  "1.0000000000000000000000000000000000000000000000000000000000000000000000000"
+                  "00000000000000000000000000000000000000000000000000000000000000000000000000"
+                  "00000000000000000000000000000000000000000000000000000000000000000000000000"
+                  "00000000000000000000000000000000000000000000000000000000000000000000000000"
+                  "0000000000000000000000000000000000000000000000000000000"),
+          QLatin1String("Very high precision 1") },
+        { 1.0e-308, 'f', 350,
+          QLatin1String("0."
+                        "00000000000000000000000000000000000000000000000000000000000000000000000000"
+                        "00000000000000000000000000000000000000000000000000000000000000000000000000"
+                        "00000000000000000000000000000000000000000000000000000000000000000000000000"
+                        "00000000000000000000000000000000000000000000000000000000000000000000000000"
+                        "000000000000999999999999999909326625337248461995470489"),
+          QLatin1String("Very small number, very high precision") },
         { std::numeric_limits<double>::epsilon(), 'g', 10, QLatin1String("2.220446049e-16") },
         { 0.0001, 'e', 1, QLatin1String("1.0e-04") },
         { 1e8, 'e', 1, QLatin1String("1.0e+08") },