QVariant: Change metatype in convert() even on failure

The documentation of convert promised that “If the cast cannot be
done, the variant is still changed to the requested type”. This was not
the case so far, because we returned too early if canConvert returned
false.
This commit changes the behavior of the method to reflect its
documentation. The documented behavior seems more useful than the
alternative of not changing the metaType, at least for common use cases
inside qtdeclarative.

Change-Id: I09b5a5efb7344e76e93de278e35c7fb2b2f87dcd
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/corelib/kernel/qvariant.cpp b/src/corelib/kernel/qvariant.cpp
index f28cd5a7a0..31c2173072 100644
--- a/src/corelib/kernel/qvariant.cpp
+++ b/src/corelib/kernel/qvariant.cpp
@@ -2032,10 +2032,10 @@ bool QVariant::convert(QMetaType targetType)
     QVariant oldValue = *this;
 
     clear();
+    create(targetType.id(), nullptr);
     if (!oldValue.canConvert(targetType))
         return false;
 
-    create(targetType.id(), nullptr);
     // Fail if the value is not initialized or was forced null by a previous failed convert.
     if (oldValue.d.is_null && oldValue.d.typeId() != QMetaType::Nullptr)
         return false;