1 files changed, 44 insertions, 21 deletions

diff --git a/src/corelib/time/qtimezoneprivate_tz.cpp b/src/corelib/time/qtimezoneprivate_tz.cpp
index a21b7ab5c8..b98fe6327a 100644
--- a/src/corelib/time/qtimezoneprivate_tz.cpp
+++ b/src/corelib/time/qtimezoneprivate_tz.cpp
@@ -350,6 +350,11 @@ static QByteArray parseTzPosixRule(QDataStream &ds)
 
 static QDate calculateDowDate(int year, int month, int dayOfWeek, int week)
 {
+    if (dayOfWeek == 0) // Sunday; we represent it as 7, POSIX uses 0
+        dayOfWeek = 7;
+    else if (dayOfWeek & ~7 || month < 1 || month > 12 || week < 1 || week > 5)
+        return QDate();
+
     QDate date(year, month, 1);
     int startDow = date.dayOfWeek();
     if (startDow <= dayOfWeek)
@@ -364,28 +369,34 @@ static QDate calculateDowDate(int year, int month, int dayOfWeek, int week)
 
 static QDate calculatePosixDate(const QByteArray &dateRule, int year)
 {
+    bool ok;
     // Can start with M, J, or a digit
     if (dateRule.at(0) == 'M') {
         // nth week in month format "Mmonth.week.dow"
         QList<QByteArray> dateParts = dateRule.split('.');
-        int month = dateParts.at(0).mid(1).toInt();
-        int week = dateParts.at(1).toInt();
-        int dow = dateParts.at(2).toInt();
-        if (dow == 0) // Sunday; we represent it as 7
-            dow = 7;
-        return calculateDowDate(year, month, dow, week);
+        if (dateParts.count() > 2) {
+            int month = dateParts.at(0).mid(1).toInt(&ok);
+            int week = ok ? dateParts.at(1).toInt(&ok) : 0;
+            int dow = ok ? dateParts.at(2).toInt(&ok) : 0;
+            if (ok)
+                return calculateDowDate(year, month, dow, week);
+        }
     } else if (dateRule.at(0) == 'J') {
         // Day of Year ignores Feb 29
-        int doy = dateRule.mid(1).toInt();
-        QDate date = QDate(year, 1, 1).addDays(doy - 1);
-        if (QDate::isLeapYear(date.year()))
-            date = date.addDays(-1);
-        return date;
+        int doy = dateRule.mid(1).toInt(&ok);
+        if (ok && doy > 0 && doy < 366) {
+            QDate date = QDate(year, 1, 1).addDays(doy - 1);
+            if (QDate::isLeapYear(date.year()) && date.month() > 2)
+                date = date.addDays(-1);
+            return date;
+        }
     } else {
         // Day of Year includes Feb 29
-        int doy = dateRule.toInt();
-        return QDate(year, 1, 1).addDays(doy - 1);
+        int doy = dateRule.toInt(&ok);
+        if (ok && doy > 0 && doy <= 366)
+            return QDate(year, 1, 1).addDays(doy - 1);
     }
+    return QDate();
 }
 
 // returns the time in seconds, INT_MIN if we failed to parse
@@ -576,7 +587,8 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
         result << data;
         return result;
     }
-
+    if (parts.count() < 3 || parts.at(1).isEmpty() || parts.at(2).isEmpty())
+        return result; // Malformed.
 
     // Get the std to dst transtion details
     QList<QByteArray> dstParts = parts.at(1).split('/');
@@ -596,6 +608,9 @@ static QVector<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArra
     else
         stdTime = QTime(2, 0, 0);
 
+    if (dstDateRule.isEmpty() || stdDateRule.isEmpty() || !dstTime.isValid() || !stdTime.isValid())
+        return result; // Malformed.
+
     // Limit year to the range QDateTime can represent:
     const int minYear = int(QDateTime::YearRange::First);
     const int maxYear = int(QDateTime::YearRange::Last);
@@ -1169,8 +1184,11 @@ public:
          */
         const StatIdent local = identify("/etc/localtime");
         const StatIdent tz = identify("/etc/TZ");
-        if (!m_name.isEmpty() && m_last.isValid() && (m_last == local || m_last == tz))
+        const StatIdent timezone = identify("/etc/timezone");
+        if (!m_name.isEmpty() && m_last.isValid()
+            && (m_last == local || m_last == tz || m_last == timezone)) {
             return m_name;
+        }
 
         m_name = etcLocalTime();
         if (!m_name.isEmpty()) {
@@ -1178,12 +1196,19 @@ public:
             return m_name;
         }
 
-        m_name = etcTZ();
-        m_last = m_name.isEmpty() ? StatIdent() : tz;
+        // Some systems (e.g. uClibc) have a default value for $TZ in /etc/TZ:
+        m_name = etcContent(QStringLiteral("/etc/TZ"));
+        if (!m_name.isEmpty()) {
+            m_last = tz;
+            return m_name;
+        }
+
+        // Gentoo still (2020, QTBUG-87326) uses this:
+        m_name = etcContent(QStringLiteral("/etc/timezone"));
+        m_last = m_name.isEmpty() ? StatIdent() : timezone;
         return m_name;
     }
 
-
 private:
     QByteArray m_name;
     struct StatIdent
@@ -1224,10 +1249,8 @@ private:
         return QByteArray();
     }
 
-    static QByteArray etcTZ()
+    static QByteArray etcContent(const QString &path)
     {
-        // Some systems (e.g. uClibc) have a default value for $TZ in /etc/TZ:
-        const QString path = QStringLiteral("/etc/TZ");
         QFile zone(path);
         if (zone.open(QIODevice::ReadOnly))
             return zone.readAll().trimmed();