Change almost all other uses of qrand() to QRandomGenerator

The vast majority is actually switched to QRandomGenerator::bounded(),
which gives a mostly uniform distribution over the [0, bound)
range. There are very few floating point cases left, as many of those
that did use floating point did not need to, after all. (I did leave
some that were too ugly for me to understand)

This commit also found a couple of calls to rand() instead of qrand().

This commit does not include changes to SSL code that continues to use
qrand() (job for someone else):
  src/network/ssl/qsslkey_qt.cpp
  src/network/ssl/qsslsocket_mac.cpp
  tests/auto/network/ssl/qsslsocket/tst_qsslsocket.cpp

Change-Id: Icd0e0d4b27cb4e5eb892fffd14b5285d43f4afbf
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 4 insertions, 5 deletions

diff --git a/src/corelib/io/qprocess_win.cpp b/src/corelib/io/qprocess_win.cpp
index 2bbc4eddd0..8da6d6b16e 100644
--- a/src/corelib/io/qprocess_win.cpp
+++ b/src/corelib/io/qprocess_win.cpp
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
-** Copyright (C) 2016 Intel Corporation.
+** Copyright (C) 2017 Intel Corporation.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
@@ -48,6 +48,7 @@
 #include <qdir.h>
 #include <qelapsedtimer.h>
 #include <qfileinfo.h>
+#include <qrandom.h>
 #include <qregexp.h>
 #include <qwineventnotifier.h>
 #include <private/qsystemlibrary_p.h>
@@ -99,10 +100,8 @@ static void qt_create_pipe(Q_PIPE *pipe, bool isInputPipe)
     wchar_t pipeName[256];
     unsigned int attempts = 1000;
     forever {
-        // ### The user must make sure to call qsrand() to make the pipe names less predictable.
-        // ### Replace the call to qrand() with a secure version, once we have it in Qt.
         _snwprintf(pipeName, sizeof(pipeName) / sizeof(pipeName[0]),
-                L"\\\\.\\pipe\\qt-%X", qrand());
+                L"\\\\.\\pipe\\qt-%X", QRandomGenerator::global()->generate());
 
         DWORD dwOpenMode = FILE_FLAG_OVERLAPPED;
         DWORD dwOutputBufferSize = 0;
diff --git a/src/corelib/io/qtemporaryfile.cpp b/src/corelib/io/qtemporaryfile.cpp
index 5865d9e19a..b8d3e859cf 100644
--- a/src/corelib/io/qtemporaryfile.cpp
+++ b/src/corelib/io/qtemporaryfile.cpp
@@ -165,7 +165,7 @@ QFileSystemEntry::NativePath QTemporaryFileName::generateNext()
 
         Char *rIter = placeholderEnd;
         while (rIter != placeholderStart) {
-            quint32 rnd = QRandomGenerator::generate();
+            quint32 rnd = QRandomGenerator::global()->generate();
             auto applyOne = [&]() {
                 quint32 v = rnd & ((1 << BitsPerCharacter) - 1);
                 rnd >>= BitsPerCharacter;