Increase sysctl argument buffer size to include null character

An UUID is 36 characters long, but sysctl and sysctlbyname return a
null terminated string with 37 characters. That was too long for the
provided buffer. Surprisingly the return code was still 0 instead of -1.
The returned buffer was empty though.

Change-Id: Ic4d20ecc1b2b3a3e98468d31ac304957d56deee9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/global/qglobal.cpp

@@ -2899,18 +2899,18 @@ enum {
 QByteArray QSysInfo::machineUniqueId()
 {
 #ifdef Q_OS_BSD4
-    char uuid[UuidStringLen];
+    char uuid[UuidStringLen + 1];
     size_t uuidlen = sizeof(uuid);
 #  ifdef KERN_HOSTUUID
     int name[] = { CTL_KERN, KERN_HOSTUUID };
     if (sysctl(name, sizeof name / sizeof name[0], &uuid, &uuidlen, nullptr, 0) == 0
             && uuidlen == sizeof(uuid))
-        return QByteArray(uuid, uuidlen);
+        return QByteArray(uuid, uuidlen - 1);
 
 #  else
     // Darwin: no fixed value, we need to search by name
     if (sysctlbyname("kern.uuid", uuid, &uuidlen, nullptr, 0) == 0 && uuidlen == sizeof(uuid))
-        return QByteArray(uuid, uuidlen);
+        return QByteArray(uuid, uuidlen - 1);
 #  endif
 #elif defined(Q_OS_UNIX)
     // The modern name on Linux is /etc/machine-id, but that path is
@@ -2974,11 +2974,11 @@ QByteArray QSysInfo::bootUniqueId()
     }
 #elif defined(Q_OS_DARWIN)
     // "kern.bootsessionuuid" is only available by name
-    char uuid[UuidStringLen];
+    char uuid[UuidStringLen + 1];
     size_t uuidlen = sizeof(uuid);
     if (sysctlbyname("kern.bootsessionuuid", uuid, &uuidlen, nullptr, 0) == 0
             && uuidlen == sizeof(uuid))
-        return QByteArray(uuid, uuidlen);
+        return QByteArray(uuid, uuidlen - 1);
 #endif
     return QByteArray();
 };