diff options
| author | Mitch Curtis <mitch.curtis@nokia.com> | 2012-08-01 16:02:10 +0200 |
|---|---|---|
| committer | Qt by Nokia <qt-info@nokia.com> | 2012-08-22 04:04:57 +0200 |
| commit | 09dd19df5c4b708960e5aade568eb15d996ef200 (patch) | |
| tree | 3a997704b1324dfb45f69d892128399affcac242 /src/corelib/global/qglobal.h | |
| parent | 7f469ef4cc614925d7a4fdb3380ff5470e25b03b (diff) | |
Do not consider sign in qIsNull.
The current implementation of qIsNull only returns true if the value is
positive zero. This behaviour is not useful for use cases like
QPointF::isNull, where QPointF(-0, -0).isNull() will return false.
There doesn't seem to be a reason why the function exhibits this
behaviour (-0.0 is not accounted for in the unit tests), and for the
case of QSizeF::scale it causes a bug: qIsNull is used to check for
division by 0.0 before it proceeds, which fails in the case of -0.0.
Task-number: QTBUG-7303
Change-Id: I767e5280bd26614e8e78ae62b274eb9bc4ade385
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>
Diffstat (limited to 'src/corelib/global/qglobal.h')
| -rw-r--r-- | src/corelib/global/qglobal.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h index 546c6cf575..2acff12e3a 100644 --- a/src/corelib/global/qglobal.h +++ b/src/corelib/global/qglobal.h @@ -813,7 +813,7 @@ Q_DECL_CONSTEXPR static inline bool qFuzzyIsNull(float f) /* This function tests a double for a null value. It doesn't check whether the actual value is 0 or close to 0, but whether - it is binary 0. + it is binary 0, disregarding sign. */ static inline bool qIsNull(double d) { @@ -823,13 +823,13 @@ static inline bool qIsNull(double d) }; U val; val.d = d; - return val.u == quint64(0); + return (val.u & Q_UINT64_C(0x7fffffffffffffff)) == 0; } /* This function tests a float for a null value. It doesn't check whether the actual value is 0 or close to 0, but whether - it is binary 0. + it is binary 0, disregarding sign. */ static inline bool qIsNull(float f) { @@ -839,7 +839,7 @@ static inline bool qIsNull(float f) }; U val; val.f = f; - return val.u == 0u; + return (val.u & 0x7fffffff) == 0; } /* |