From 954b73445cfbfef01207d51d1b986c6dd796c6d0 Mon Sep 17 00:00:00 2001 From: Edward Welbourne Date: Mon, 1 Apr 2019 15:22:15 +0200 Subject: Refine underflow check in QLocaleData::convertDoubleToFloat() A string can parse as a non-zero double that's smaller than the smallest float yet be a faithful representation of the smallest float. So rather than testing for non-zero doubles less than the smallest float, test for non-zero doubles that cast to float zero; these underflow. This means small values close below the smallest float shall round up to it, rather than down to zero, requiring a tweak to an existing test. Added a test for the boundary case (and tidied the test data). Fixes: QTBUG-74833 Change-Id: I4cb30b3c0e54683574b98253505607caaf88fbfb Reviewed-by: Thiago Macieira --- tests/auto/corelib/tools/qlocale/tst_qlocale.cpp | 43 +++++++++++++++--------- 1 file changed, 28 insertions(+), 15 deletions(-) (limited to 'tests/auto') diff --git a/tests/auto/corelib/tools/qlocale/tst_qlocale.cpp b/tests/auto/corelib/tools/qlocale/tst_qlocale.cpp index 5d344834e6..279ee2e8a0 100644 --- a/tests/auto/corelib/tools/qlocale/tst_qlocale.cpp +++ b/tests/auto/corelib/tools/qlocale/tst_qlocale.cpp @@ -952,29 +952,42 @@ void tst_QLocale::stringToDouble() void tst_QLocale::stringToFloat_data() { + using Bounds = std::numeric_limits; toReal_data(); - if (std::numeric_limits::has_infinity) { - double huge = std::numeric_limits::infinity(); - QTest::newRow("C inf") << QString("C") << QString("inf") << true << huge; - QTest::newRow("C +inf") << QString("C") << QString("+inf") << true << +huge; - QTest::newRow("C -inf") << QString("C") << QString("-inf") << true << -huge; + const QString C(QStringLiteral("C")); + if (Bounds::has_infinity) { + double huge = Bounds::infinity(); + QTest::newRow("C inf") << C << QString("inf") << true << huge; + QTest::newRow("C +inf") << C << QString("+inf") << true << +huge; + QTest::newRow("C -inf") << C << QString("-inf") << true << -huge; // Overflow float, but not double: - QTest::newRow("C big") << QString("C") << QString("3.5e38") << false << huge; - QTest::newRow("C -big") << QString("C") << QString("-3.5e38") << false << -huge; + QTest::newRow("C big") << C << QString("3.5e38") << false << huge; + QTest::newRow("C -big") << C << QString("-3.5e38") << false << -huge; // Overflow double, too: - QTest::newRow("C huge") << QString("C") << QString("2e308") << false << huge; - QTest::newRow("C -huge") << QString("C") << QString("-2e308") << false << -huge; + QTest::newRow("C huge") << C << QString("2e308") << false << huge; + QTest::newRow("C -huge") << C << QString("-2e308") << false << -huge; } - if (std::numeric_limits::has_quiet_NaN) - QTest::newRow("C qnan") << QString("C") << QString("NaN") << true << double(std::numeric_limits::quiet_NaN()); + if (Bounds::has_quiet_NaN) + QTest::newRow("C qnan") << C << QString("NaN") << true << double(Bounds::quiet_NaN()); + + // Minimal float: shouldn't underflow + QTest::newRow("C float min") + << C << QLocale::c().toString(Bounds::denorm_min()) << true << double(Bounds::denorm_min()); + QTest::newRow("C float -min") + << C << QLocale::c().toString(-Bounds::denorm_min()) << true << -double(Bounds::denorm_min()); // Underflow float, but not double: - QTest::newRow("C small") << QString("C") << QString("1e-45") << false << 0.; - QTest::newRow("C -small") << QString("C") << QString("-1e-45") << false << 0.; + QTest::newRow("C small") << C << QString("7e-46") << false << 0.; + QTest::newRow("C -small") << C << QString("-7e-46") << false << 0.; + using Double = std::numeric_limits; + QTest::newRow("C double min") + << C << QLocale::c().toString(Double::denorm_min()) << false << 0.0; + QTest::newRow("C double -min") + << C << QLocale::c().toString(-Double::denorm_min()) << false << 0.0; // Underflow double, too: - QTest::newRow("C tiny") << QString("C") << QString("2e-324") << false << 0.; - QTest::newRow("C -tiny") << QString("C") << QString("-2e-324") << false << 0.; + QTest::newRow("C tiny") << C << QString("2e-324") << false << 0.; + QTest::newRow("C -tiny") << C << QString("-2e-324") << false << 0.; } void tst_QLocale::stringToFloat() -- cgit v1.2.3