Fix parsing of day-of-week names that start with another name

Task-number: QTBUG-59159
Change-Id: I95c9e502ccc74af3bcf0fffd14a69e0cd27ce96b
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

2 files changed, 59 insertions, 32 deletions

diff --git a/src/corelib/tools/qdatetimeparser.cpp b/src/corelib/tools/qdatetimeparser.cpp
index d66416207b..c8aa4fbc89 100644
--- a/src/corelib/tools/qdatetimeparser.cpp
+++ b/src/corelib/tools/qdatetimeparser.cpp
@@ -49,7 +49,7 @@
 
 //#define QDATETIMEPARSER_DEBUG
 #if defined (QDATETIMEPARSER_DEBUG) && !defined(QT_NO_DEBUG_STREAM)
-#  define QDTPDEBUG qDebug() << QString("%1:%2").arg(__FILE__).arg(__LINE__)
+#  define QDTPDEBUG qDebug()
 #  define QDTPDEBUGN qDebug
 #else
 #  define QDTPDEBUG if (false) qDebug()
@@ -1325,39 +1325,16 @@ int QDateTimeParser::findDay(const QString &str1, int startDay, int sectionIndex
         }
         const QLocale l = locale();
         for (int day=startDay; day<=7; ++day) {
-            const QString str2 = l.dayName(day, sn.count == 4 ? QLocale::LongFormat : QLocale::ShortFormat);
-
-            if (str1.startsWith(str2.toLower())) {
-                if (used)
-                    *used = str2.size();
-                if (usedDay) {
-                    *usedDay = str2;
-                }
-                return day;
-            }
-            if (context == FromString)
-                continue;
+            const QString dayName = l.dayName(day, sn.count == 4 ? QLocale::LongFormat : QLocale::ShortFormat);
+            const QString str2 = dayName.toLower();
 
             const int limit = qMin(str1.size(), str2.size());
-            bool found = true;
-            for (int i=0; i<limit; ++i) {
-                if (str1.at(i) != str2.at(i) && !str1.at(i).isSpace()) {
-                    if (i > bestCount) {
-                        bestCount = i;
-                        bestMatch = day;
-                    }
-                    found = false;
-                    break;
-                }
-
-            }
-            if (found) {
-                if (used)
-                    *used = limit;
-                if (usedDay)
-                    *usedDay = str2;
-
-                return day;
+            int i = 0;
+            while (i < limit && str1.at(i) == str2.at(i))
+                ++i;
+            if (i > bestCount) {
+                bestCount = i;
+                bestMatch = day;
             }
         }
         if (usedDay && bestMatch != -1) {
diff --git a/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp b/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp
index 33844feafe..b6c740998e 100644
--- a/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp
+++ b/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp
@@ -117,6 +117,8 @@ private slots:
     void fromStringDateFormat();
     void fromStringStringFormat_data();
     void fromStringStringFormat();
+    void fromStringStringFormatLocale_data();
+    void fromStringStringFormatLocale();
 #ifdef Q_OS_WIN
     void fromString_LOCALE_ILDATE();
 #endif
@@ -2337,6 +2339,54 @@ void tst_QDateTime::fromStringStringFormat()
     QCOMPARE(dt, expected);
 }
 
+void tst_QDateTime::fromStringStringFormatLocale_data()
+{
+    QTest::addColumn<QString>("string");
+    QTest::addColumn<QString>("format");
+    QTest::addColumn<QLocale>("locale");
+    QTest::addColumn<QDateTime>("expected");
+
+    QLocale c = QLocale::c();
+    QDateTime dt(QDate(2017, 02, 25), QTime(17, 21, 25));
+
+    // The formats correspond to the locale formats, with the timezone removed.
+    // We hardcode them in case an update to the locale DB changes them.
+
+    QTest::newRow("C:long") << "Saturday, 25 February 2017 17:21:25" << "dddd, d MMMM yyyy HH:mm:ss" << c << dt;
+    QTest::newRow("C:short") << "25 Feb 2017 17:21:25" << "d MMM yyyy HH:mm:ss" << c << dt;
+    QTest::newRow("C:narrow") << "25 Feb 2017 17:21:25" << "d MMM yyyy HH:mm:ss" << c << dt;
+
+    QLocale fr(QLocale::French);
+    QTest::newRow("fr:long") << "Samedi 25 février 2017 17:21:25" << "dddd d MMMM yyyy HH:mm:ss" << fr << dt;
+    QTest::newRow("fr:short") << "25/02/2017 17:21" << "dd/MM/yyyy HH:mm" << fr << dt.addSecs(-25);
+
+    // In Turkish, the word for Friday ("Cuma") is a prefix for the word for
+    // Saturday ("Cumartesi")
+    QLocale tr(QLocale::Turkish);
+    QTest::newRow("tr:long") << "25 Şubat 2017 Cumartesi 17:21:25" << "d MMMM yyyy dddd HH:mm:ss" << tr << dt;
+    QTest::newRow("tr:long2") << "24 Şubat 2017 Cuma 17:21:25" << "d MMMM yyyy dddd HH:mm:ss" << tr << dt.addDays(-1);
+    QTest::newRow("tr:mashed") << "25 Şubat2017 Cumartesi17:21:25" << "d MMMMyyyy ddddHH:mm:ss" << tr << dt;
+    QTest::newRow("tr:mashed2") << "24 Şubat2017 Cuma17:21:25" << "d MMMMyyyy ddddHH:mm:ss" << tr << dt.addDays(-1);
+    QTest::newRow("tr:short") << "25.02.2017 17:21" << "d.MM.yyyy HH:mm" << tr << dt.addSecs(-25);
+}
+
+void tst_QDateTime::fromStringStringFormatLocale()
+{
+    QFETCH(QString, string);
+    QFETCH(QString, format);
+    QFETCH(QLocale, locale);
+    QFETCH(QDateTime, expected);
+
+    QDateTime parsed = locale.toDateTime(string, format);
+    QCOMPARE(parsed, expected);
+
+    parsed = locale.toDateTime(string.toLower(), format);
+    QCOMPARE(parsed, expected);
+
+    parsed = locale.toDateTime(string.toUpper(), format);
+    QCOMPARE(parsed, expected);
+}
+
 #ifdef Q_OS_WIN
 // Windows only
 void tst_QDateTime::fromString_LOCALE_ILDATE()