Coverity complains that qCountLeadingZeroBits() may return 64 and then
the RHS will be out-of-range for int. Of course, 64 leading zero bits
means that the argument is 0, which we excluded in the first `if` of
the if-else chain.
I can only guess (because it doesn't tell me which value of `bytes` it
is using for the analysis) that Coverity assumes bytes ==
numeric_limits<qint64>::min() and considers the overflow in qAbs() to
yield a 0, because, it being UB, it may yield anything.
Be that as it may, the fact remains that formattedDataSize() invokes
UB when passed numeric_limits<qint64>::min(), as confirmed by ubsan:
global/qnumeric.h:479:26: runtime error: negation of -9223372036854775808 cannot be represented in type 'long long int'; cast to an unsigned type to negate this value to itself
text/qlocale.cpp:5062:82: runtime error: signed integer overflow: -2147483648 * 3 cannot be represented in type 'int'
text/qlocale.cpp:5062:26: runtime error: division by zero
FAIL! : tst_QLocale::formattedDataSize(English-Decimal-min) Compared values are not the same
Actual (QLocale(language).formattedDataSize(bytes, decimalPlaces, units)): "-inf bytes"
Expected ("output") : "-9.22 EB"
So fix the overflow by using the new QtPrivate::qUnsignedAbs(). Then
sit back and await Coverity's verdict on the next run.
[ChangeLog][QtCore][QLocale] Fix issue when calling
formattedDataSize() with numeric_limits<qint64>::min().
Amends 9d23aebb27.
Pick-to: 6.5 6.2 5.15
Coverity-Id: 474294
Change-Id: I9a5a5acbdcf881a624bb827ca1dd970771f1bb6e
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
(cherry picked from commit b93575de01760ff2ab0d817557a642c71cdb4414)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 6cefb8be965759cc022ce3ef1ae7a722f0566ce7)
73c44c8381