From 90ae7d9b7244b3d9a14f03a96e919859580f5a90 Mon Sep 17 00:00:00 2001
From: Markus Mittendrein <maxmitti@maxmitti.tk>
Date: Sat, 15 Jan 2022 17:49:24 +0100
Subject: Replace uses of q(s)rand with C++11 <random> stuff

---
 src/ProcessManager.cpp |  4 +++-
 src/crsm.cpp           | 16 +++++++++-------
 src/crsm.hpp           |  5 +++++
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/ProcessManager.cpp b/src/ProcessManager.cpp
index 234d456..e34ebfc 100644
--- a/src/ProcessManager.cpp
+++ b/src/ProcessManager.cpp
@@ -6,6 +6,8 @@
 #include <QDebug>
 #include <QTextCodec>
 
+#include <random>
+
 ProcessManager::ProcessManager(const QString &newPrefix, const QString &newId, bool useStdErr, QTextCodec* argumentsCodec, QObject *parent) : QObject(parent), prefix(newPrefix), id(newId), useStdErr(useStdErr)
 {
     if(argumentsCodec == nullptr)
@@ -19,7 +21,7 @@ ProcessManager::ProcessManager(const QString &newPrefix, const QString &newId, b
 
     if(id.isEmpty())
     {
-        id = QString::number(qrand()) + "-";
+        id = QString::number(std::random_device{}()) + "-";
     }
     stdIn.setFileName(prefix + id + "stdin");
     stdOut.setFileName(prefix + id + "stdout");
diff --git a/src/crsm.cpp b/src/crsm.cpp
index 93dc9d7..b5f0049 100644
--- a/src/crsm.cpp
+++ b/src/crsm.cpp
@@ -19,7 +19,6 @@ CRSM::CRSM(QObject *parent) :
     control.setController(this);
     parser.addTarget(this);
 
-    qsrand((uint)QDateTime::currentMSecsSinceEpoch());
     codec = QTextCodec::codecForName("Windows-1252");
 
     outputBuffer.setFileName(MGMT_BUFFER_FILENAME);
@@ -714,14 +713,15 @@ void CRSM::dccChatRequest(const ClientInfo &client, QString extraArgs)
 }
 
 // modified version of http://stackoverflow.com/a/18866593
-QString GetRandomString(int length = 5)
+QString GetRandomString(int length, std::default_random_engine& rng)
 {
     static const QString possibleCharacters("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789");
 
+    std::uniform_int_distribution<int> dist{0, possibleCharacters.length() - 1};
     QString randomString;
     for(int i=0; i<length; ++i)
     {
-        int index = qrand() % possibleCharacters.length();
+        const auto index = dist(rng);
         QChar nextChar = possibleCharacters.at(index);
         randomString.append(nextChar);
     }
@@ -748,7 +748,7 @@ void CRSM::newDCCConnection()
     QString identifier;
     do
     {
-        identifier = GetRandomString();
+        identifier = GetRandomString(5, rng);
     }
     while(dccConnectionIdentifiers.contains(identifier));
 
@@ -775,12 +775,14 @@ void CRSM::disconnectedDCCConnection()
 void CRSM::updateNextAutoScens()
 {
     if(autolist.length() <= 0) return;
+
+    std::uniform_int_distribution<int> autolistDist{0, autolist.length() - 1};
     while(nextAutoScens.length() < Config.Hosting.UserListLength || (nextAutoScens.length() <= 0))
     {
         ScenarioSettings next("");
         if(Config.Hosting.RandomizeAuto)
         {
-            next = autolist.at(qrand() % autolist.length());
+            next = autolist.at(autolistDist(rng));
         }
         else
         {
@@ -789,7 +791,7 @@ void CRSM::updateNextAutoScens()
         }
         if(next.randomLeague)
         {
-            next.league = qrand() % 2;
+            next.league = boolRng();
         }
         nextAutoScens.append(next);
     }
@@ -2379,7 +2381,7 @@ void CRSM::watchdog()
     if(watchDogString.isEmpty())
     {
         watchDogTimer.start(Config.Clonk.Server.Watchdog.Timeout * 1000);
-        watchDogString = GetRandomString(20);
+        watchDogString = GetRandomString(20, rng);
         control.watchdog(watchDogString);
     }
     else
diff --git a/src/crsm.hpp b/src/crsm.hpp
index e96929f..5a3ba06 100644
--- a/src/crsm.hpp
+++ b/src/crsm.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <random>
+
 #include <QObject>
 #include <QProcess>
 #include <QTextStream>
@@ -179,6 +181,9 @@ private:
     QTimer watchDogTimer;
     QString watchDogString;
 
+    std::default_random_engine rng{std::random_device{}()};
+    std::independent_bits_engine<std::default_random_engine, 1, bool> boolRng{std::default_random_engine{rng()}};
+
     bool ok = false;
     bool hostingIsErrorDeactivated = false;
 
-- 
cgit v1.2.3-54-g00ecf