Fix process info not available in flatpak

Since we are in a sandbox, tcgetpgrp doesn't work. To work around
this limitation, get process info using ps

BUG: 507763
BUG: 508216

src/ProcessInfo.cpp

@@ -35,6 +35,7 @@
 
 // KDE
 #include <KConfigGroup>
+#include <KSandbox>
 #include <KSharedConfig>
 #include <KUser>
 
@@ -787,6 +788,84 @@ private:
 QString LinuxProcessInfo::_createdAppCGroupPath = QString();
 bool LinuxProcessInfo::_cGroupCreationFailed = false;
 
+class FlatpakProcessInfo : public ProcessInfo
+{
+public:
+    FlatpakProcessInfo(int pid, QByteArrayView tty)
+        : ProcessInfo(pid)
+    {
+        QProcess proc;
+        proc.setProgram(QStringLiteral("ps"));
+        proc.setArguments({
+            QStringLiteral("-o"),
+            QStringLiteral("%U\t%p\t%c"),
+            QStringLiteral("--tty"),
+            QString::fromLatin1(tty.data()),
+            QStringLiteral("--no-headers"),
+        });
+
+        KSandbox::startHostProcess(proc, QProcess::ReadOnly);
+
+        proc.waitForStarted();
+        proc.waitForFinished();
+
+        const QString out = QString::fromUtf8(proc.readAllStandardOutput());
+        for (QStringView line : QStringTokenizer(out, u'\n', Qt::SkipEmptyParts)) {
+            using Container = QVarLengthArray<QStringView, 4>;
+            const Container tokens = QStringTokenizer(line, u'\t', Qt::SkipEmptyParts).toContainer<Container>();
+            if (tokens[1].toInt() == pid) {
+                setUserName(tokens[0].trimmed().toString());
+                setPid(tokens[1].trimmed().toInt());
+                setName(tokens[2].trimmed().toString());
+            }
+        }
+    }
+
+    void readProcessInfo(int) override
+    {
+        /* done in ctor */
+    }
+
+    bool readProcessName(int) override
+    {
+        return true;
+    }
+
+    bool readCurrentDir(int) override
+    {
+        bool ok = false;
+        QString pidString = QString::number(pid(&ok));
+        if (!ok) {
+            return false;
+        }
+
+        QProcess proc;
+        proc.setProgram(QStringLiteral("pwdx"));
+        proc.setArguments({pidString});
+        KSandbox::startHostProcess(proc, QProcess::ReadOnly);
+        if (proc.waitForStarted() && proc.waitForFinished()) {
+            proc.setReadChannel(QProcess::StandardOutput);
+            quint8 buffer[4096];
+            auto line = proc.readLineInto(buffer).trimmed();
+            if (int colon = line.indexOf(": "); colon != -1) {
+                setCurrentDir(QString::fromUtf8(line.mid(colon + 2)));
+                return true;
+            }
+        }
+        return false;
+    }
+
+    bool readArguments(int) override
+    {
+        return false;
+    }
+
+    void readUserName(void) override
+    {
+        /* done in ctor */
+    }
+};
+
 #elif defined(Q_OS_FREEBSD)
 class FreeBSDProcessInfo : public UnixProcessInfo
 {
@@ -1311,11 +1390,19 @@ private:
 };
 #endif
 
-ProcessInfo *ProcessInfo::newInstance(int pid, int sessionPid)
+ProcessInfo *ProcessInfo::newInstance(int pid, int sessionPid, QByteArrayView tty)
 {
     ProcessInfo *info;
 #if defined(Q_OS_LINUX)
-    info = new LinuxProcessInfo(pid, sessionPid);
+    if (KSandbox::isFlatpak()) {
+        if (tty.isEmpty()) {
+            info = new NullProcessInfo(pid);
+        } else {
+            info = new FlatpakProcessInfo(pid, tty);
+        }
+    } else {
+        info = new LinuxProcessInfo(pid, sessionPid);
+    }
 #elif defined(Q_OS_SOLARIS)
     info = new SolarisProcessInfo(pid);
 #elif defined(Q_OS_MACOS)

src/ProcessInfo.h

@@ -68,8 +68,9 @@ public:
      * @param pid The pid of the process to examine
      * @param sessionPid -1 if examined process is session process,
      *		else will be pid of session process of the tab housing examined process
+     * @param tty the current tty, used by flatpak
      */
-    static ProcessInfo *newInstance(int pid, int sessionPid = -1);
+    static ProcessInfo *newInstance(int pid, int sessionPid = -1, QByteArrayView tty = QByteArrayView());
 
     virtual ~ProcessInfo()
     {

src/Pty.cpp

@@ -23,6 +23,7 @@
 
 // KDE
 #include <KPtyDevice>
+#include <KSandbox>
 
 using Konsole::Pty;
 
@@ -303,6 +304,36 @@ void Pty::closePty()
 
 int Pty::foregroundProcessGroup() const
 {
+    if (KSandbox::isFlatpak()) {
+        QProcess proc;
+        proc.setProgram(QStringLiteral("ps"));
+        proc.setArguments({QStringLiteral("-o"),
+                           QStringLiteral("%p\t"),
+                           QStringLiteral("-o"),
+                           QStringLiteral("stat"),
+                           QStringLiteral("-t"),
+                           QStringLiteral("%1").arg(pty()->ttyName()),
+                           QStringLiteral("--no-headers")});
+
+        KSandbox::startHostProcess(proc, QProcess::ReadOnly);
+        if (proc.waitForStarted() && proc.waitForFinished()) {
+            while (proc.canReadLine()) {
+                quint8 buffer[256];
+                const QByteArrayView line = proc.readLineInto(buffer);
+                int i = line.indexOf('\t');
+                if (i == -1) {
+                    return 0;
+                }
+                QByteArrayView pid = line.mid(0, i);
+                QByteArrayView stat = line.mid(i + 1);
+                if (stat.contains("+")) {
+                    return pid.trimmed().toInt();
+                }
+            }
+        }
+        return 0;
+    }
+
     const int master_fd = pty()->masterFd();
 
     if (master_fd >= 0) {

src/session/Session.cpp

@@ -289,7 +289,8 @@ void Session::setInitialWorkingDirectory(const QString &dir)
 
 QString Session::currentWorkingDirectory()
 {
-    if (_reportedWorkingUrl.isValid() && _reportedWorkingUrl.isLocalFile() && (_reportedWorkingUrl.host().length() == 0 || _reportedWorkingUrl.host().compare(QSysInfo::machineHostName(), Qt::CaseInsensitive) == 0)) {
+    if (_reportedWorkingUrl.isValid() && _reportedWorkingUrl.isLocalFile()
+        && (_reportedWorkingUrl.host().length() == 0 || _reportedWorkingUrl.host().compare(QSysInfo::machineHostName(), Qt::CaseInsensitive) == 0)) {
         return _reportedWorkingUrl.path();
     }
 
@@ -1224,7 +1225,30 @@ void Session::updateSessionProcessInfo()
     // return 0
     if ((_sessionProcessInfo == nullptr) || (processId() != 0 && processId() != _sessionProcessInfo->pid(&ok))) {
         delete _sessionProcessInfo;
-        _sessionProcessInfo = ProcessInfo::newInstance(processId());
+
+        int sessionPid = processId();
+        if (KSandbox::isFlatpak()) {
+            QProcess proc;
+            proc.setProgram(QStringLiteral("ps"));
+            proc.setArguments({QStringLiteral("-o"),
+                               QStringLiteral("pid"),
+                               QStringLiteral("-t"),
+                               QStringLiteral("%1").arg(_shellProcess->pty()->ttyName()),
+                               QStringLiteral("--no-headers")});
+            KSandbox::startHostProcess(proc, QProcess::ReadOnly);
+            if (proc.waitForStarted() && proc.waitForFinished()) {
+                proc.setReadChannel(QProcess::StandardOutput);
+                quint8 buffer[256];
+                auto line = proc.readLineInto(buffer).trimmed();
+                bool ok;
+                auto pid = line.toInt(&ok);
+                if (ok) {
+                    sessionPid = pid;
+                }
+            }
+        }
+
+        _sessionProcessInfo = ProcessInfo::newInstance(sessionPid, -1, _shellProcess->pty()->ttyName());
         _sessionProcessInfo->setUserHomeDir();
     }
     _sessionProcessInfo->update();
@@ -1237,7 +1261,7 @@ bool Session::updateForegroundProcessInfo()
     const int foregroundPid = _shellProcess->foregroundProcessGroup();
     if (foregroundPid != _foregroundPid) {
         delete _foregroundProcessInfo;
-        _foregroundProcessInfo = ProcessInfo::newInstance(foregroundPid, processId());
+        _foregroundProcessInfo = ProcessInfo::newInstance(foregroundPid, processId(), _shellProcess->pty()->ttyName());
         _foregroundPid = foregroundPid;
     }