JSON: remove braces from UUID text representations

[ChangeLog][QtCore][QJsonValue] fromVariant() conversion now converts
from QUrl and QUuid using special encoding forms to ensure best JSON
compatibility.

Change-Id: I56b444f9d6274221a3b7fffd150cdc5ca1f87ff1
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

src/corelib/serialization/qjsonvalue.cpp

@@ -41,6 +41,7 @@
 #include <qjsonvalue.h>
 #include <qjsonarray.h>
 #include <qurl.h>
+#include <quuid.h>
 #include <qvariant.h>
 #include <qstringlist.h>
 #include <qdebug.h>
@@ -416,6 +417,12 @@ QJsonValue &QJsonValue::operator =(const QJsonValue &other)
             \endlist
         \li QJsonValue::String. The conversion will use QUrl::toString() with flag
             QUrl::FullyEncoded, so as to ensure maximum compatibility in parsing the URL
+    \row
+        \li
+            \list
+                \li QMetaType::QUuid
+            \endlist
+        \li QJsonValue::String. Since Qt 5.11, the resulting string will not include braces
     \endtable
 
     For all other QVariant types a conversion to a QString will be attempted. If the returned string
@@ -450,6 +457,8 @@ QJsonValue QJsonValue::fromVariant(const QVariant &variant)
 #ifndef QT_BOOTSTRAPPED
     case QVariant::Url:
         return QJsonValue(variant.toUrl().toString(QUrl::FullyEncoded));
+    case QVariant::Uuid:
+        return variant.toUuid().toString(QUuid::WithoutBraces);
     case QMetaType::QJsonValue:
         return variant.toJsonValue();
     case QMetaType::QJsonObject:

tests/auto/corelib/serialization/json/tst_qtjson.cpp

@@ -1184,6 +1184,8 @@ void tst_QtJson::fromVariantSpecial_data()
     // Qt types with special encoding
     QTest::newRow("url") << QVariant(QUrl("https://example.com/\xc2\xa9 "))
                          << QJsonValue("https://example.com/%C2%A9%20");
+    QTest::newRow("uuid") << QVariant(QUuid(0x40c01df6, 0x1ad5, 0x4762, 0x9c, 0xfe, 0xfd, 0xba, 0xfa, 0xb5, 0xde, 0xf8))
+                          << QJsonValue("40c01df6-1ad5-4762-9cfe-fdbafab5def8");
 }
 
 void tst_QtJson::fromVariantSpecial()