2 files changed, 45 insertions, 25 deletions
diff --git a/src/corelib/tools/qdatetime.cpp b/src/corelib/tools/qdatetime.cpp
index bcdbc5af2a..11c023f762 100644
--- a/src/corelib/tools/qdatetime.cpp
+++ b/src/corelib/tools/qdatetime.cpp
@@ -1642,10 +1642,14 @@ QString QTime::toString(Qt::DateFormat format) const
          \li the hour with a leading zero (00 to 23, even with AM/PM display)
     \row \li m \li the minute without a leading zero (0 to 59)
     \row \li mm \li the minute with a leading zero (00 to 59)
-    \row \li s \li the second without a leading zero (0 to 59)
-    \row \li ss \li the second with a leading zero (00 to 59)
-    \row \li z \li the milliseconds without leading zeroes (0 to 999)
-    \row \li zzz \li the milliseconds with leading zeroes (000 to 999)
+    \row \li s \li the whole second, without any leading zero (0 to 59)
+    \row \li ss \li the whole second, with a leading zero where applicable (00 to 59)
+    \row \li z \li the fractional part of the second, to go after a decimal
+                point, without trailing zeroes (0 to 999).  Thus "\c{s.z}"
+                reports the seconds to full available (millisecond) precision
+                without trailing zeroes.
+    \row \li zzz \li the fractional part of the second, to millisecond
+                precision, including trailing zeroes where applicable (000 to 999).
     \row \li AP or A
          \li use AM/PM display. \e A/AP will be replaced by either
              QLocale::amText() or QLocale::pmText().
@@ -1991,10 +1995,14 @@ QTime QTime::fromString(const QString& string, Qt::DateFormat format)
          \li the hour with a leading zero (00 to 23 or 01 to 12 if AM/PM display)
     \row \li m \li the minute without a leading zero (0 to 59)
     \row \li mm \li the minute with a leading zero (00 to 59)
-    \row \li s \li the second without a leading zero (0 to 59)
-    \row \li ss \li the second with a leading zero (00 to 59)
-    \row \li z \li the milliseconds without leading zeroes (0 to 999)
-    \row \li zzz \li the milliseconds with leading zeroes (000 to 999)
+    \row \li s \li the whole second, without any leading zero (0 to 59)
+    \row \li ss \li the whole second, with a leading zero where applicable (00 to 59)
+    \row \li z \li the fractional part of the second, to go after a decimal
+                point, without trailing zeroes (0 to 999).  Thus "\c{s.z}"
+                reports the seconds to full available (millisecond) precision
+                without trailing zeroes.
+    \row \li zzz \li the fractional part of the second, to millisecond
+                precision, including trailing zeroes where applicable (000 to 999).
     \row \li AP
          \li interpret as an AM/PM time. \e AP must be either "AM" or "PM".
     \row \li ap
@@ -3895,10 +3903,14 @@ QString QDateTime::toString(Qt::DateFormat format) const
          \li the hour with a leading zero (00 to 23, even with AM/PM display)
     \row \li m \li the minute without a leading zero (0 to 59)
     \row \li mm \li the minute with a leading zero (00 to 59)
-    \row \li s \li the second without a leading zero (0 to 59)
-    \row \li ss \li the second with a leading zero (00 to 59)
-    \row \li z \li the milliseconds without leading zeroes (0 to 999)
-    \row \li zzz \li the milliseconds with leading zeroes (000 to 999)
+    \row \li s \li the whole second without a leading zero (0 to 59)
+    \row \li ss \li the whole second with a leading zero where applicable (00 to 59)
+    \row \li z \li the fractional part of the second, to go after a decimal
+                point, without trailing zeroes (0 to 999).  Thus "\c{s.z}"
+                reports the seconds to full available (millisecond) precision
+                without trailing zeroes.
+    \row \li zzz \li the fractional part of the second, to millisecond
+                precision, including trailing zeroes where applicable (000 to 999).
     \row \li AP or A
          \li use AM/PM display. \e A/AP will be replaced by either "AM" or "PM".
     \row \li ap or a
@@ -3912,13 +3924,14 @@ QString QDateTime::toString(Qt::DateFormat format) const
     in the output. Formats without separators (e.g. "HHmm") are currently not supported.
 
     Example format strings (assumed that the QDateTime is 21 May 2001
-    14:13:09):
+    14:13:09.120):
 
     \table
     \header \li Format       \li Result
     \row \li dd.MM.yyyy      \li 21.05.2001
     \row \li ddd MMMM d yy   \li Tue May 21 01
-    \row \li hh:mm:ss.zzz    \li 14:13:09.042
+    \row \li hh:mm:ss.zzz    \li 14:13:09.120
+    \row \li hh:mm:ss.z      \li 14:13:09.12
     \row \li h:m:s ap        \li 2:13:9 pm
     \endtable
 
@@ -4918,10 +4931,14 @@ QDateTime QDateTime::fromString(const QString& string, Qt::DateFormat format)
             \li the hour with a leading zero (00 to 23, even with AM/PM display)
     \row \li m \li the minute without a leading zero (0 to 59)
     \row \li mm \li the minute with a leading zero (00 to 59)
-    \row \li s \li the second without a leading zero (0 to 59)
-    \row \li ss \li the second with a leading zero (00 to 59)
-    \row \li z \li the milliseconds without leading zeroes (0 to 999)
-    \row \li zzz \li the milliseconds with leading zeroes (000 to 999)
+    \row \li s \li the whole second without a leading zero (0 to 59)
+    \row \li ss \li the whole second with a leading zero where applicable (00 to 59)
+    \row \li z \li the fractional part of the second, to go after a decimal
+                point, without trailing zeroes (0 to 999).  Thus "\c{s.z}"
+                reports the seconds to full available (millisecond) precision
+                without trailing zeroes.
+    \row \li zzz \li the fractional part of the second, to millisecond
+                precision, including trailing zeroes where applicable (000 to 999).
     \row \li AP or A
          \li interpret as an AM/PM time. \e AP must be either "AM" or "PM".
     \row \li ap or a
diff --git a/src/corelib/tools/qlocale.cpp b/src/corelib/tools/qlocale.cpp
index dcdf6b5ed7..ab95f60115 100644
--- a/src/corelib/tools/qlocale.cpp
+++ b/src/corelib/tools/qlocale.cpp
@@ -2742,14 +2742,17 @@ QString QLocalePrivate::dateTimeToString(const QString &format, const QDateTime
                 } else {
                     repeat = 1;
                 }
-                switch (repeat) {
-                case 1:
-                    result.append(m_data->longLongToString(time.msec()));
-                    break;
-                case 3:
-                    result.append(m_data->longLongToString(time.msec(), -1, 10, 3, QLocaleData::ZeroPadded));
-                    break;
+
+                // note: the millisecond component is treated like the decimal part of the seconds
+                // so ms == 2 is always printed as "002", but ms == 200 can be either "2" or "200"
+                result.append(m_data->longLongToString(time.msec(), -1, 10, 3, QLocaleData::ZeroPadded));
+                if (repeat == 1) {
+                    if (result.endsWith(zero()))
+                        result.chop(1);
+                    if (result.endsWith(zero()))
+                        result.chop(1);
                 }
+
                 break;
 
             case 't':