MultiMC5/launcher/DesktopServices.cpp

#include "DesktopServices.h"
#include <QDir>
#include <QDesktopServices>
#include <QProcess>
#include <QDebug>

/**
 * This shouldn't exist, but until QTBUG-9328 and other unreported bugs are fixed, it needs to be a thing.
 */
#if defined(Q_OS_LINUX)

#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>

template <typename T>
bool IndirectOpen(T callable, qint64 *pid_forked = nullptr)
{
    auto pid = fork();
    if(pid_forked)
    {
        if(pid > 0)
            *pid_forked = pid;
        else
            *pid_forked = 0;
    }
    if(pid == -1)
    {
        qWarning() << "IndirectOpen failed to fork: " << errno;
        return false;
    }
    // child - do the stuff
    if(pid == 0)
    {
        // unset all this garbage so it doesn't get passed to the child process
        qunsetenv("LD_PRELOAD");
        qunsetenv("LD_LIBRARY_PATH");
        qunsetenv("LD_DEBUG");
        qunsetenv("QT_PLUGIN_PATH");
        qunsetenv("QT_FONTPATH");

        // open the URL
        auto status = callable();

        // detach from the parent process group.
        setsid();

        // die. now. do not clean up anything, it would just hang forever.
        _exit(status ? 0 : 1);
    }
    else
    {
        //parent - assume it worked.
        int status;
        while (waitpid(pid, &status, 0))
        {
            if(WIFEXITED(status))
            {
                return WEXITSTATUS(status) == 0;
            }
            if(WIFSIGNALED(status))
            {
                return false;
            }
        }
        return true;
    }
}
#endif

namespace DesktopServices {
bool openDirectory(const QString &path, bool ensureExists)
{
    qDebug() << "Opening directory" << path;
    QDir parentPath;
    QDir dir(path);
    if (!dir.exists())
    {
        parentPath.mkpath(dir.absolutePath());
    }
    auto f = [&]()
    {
        return QDesktopServices::openUrl(QUrl::fromLocalFile(dir.absolutePath()));
    };
#if defined(Q_OS_LINUX)
    return IndirectOpen(f);
#else
    return f();
#endif
}

bool openFile(const QString &path)
{
    qDebug() << "Opening file" << path;
    auto f = [&]()
    {
        return QDesktopServices::openUrl(QUrl::fromLocalFile(path));
    };
#if defined(Q_OS_LINUX)
    return IndirectOpen(f);
#else
    return f();
#endif
}

bool openFile(const QString &application, const QString &path, const QString &workingDirectory, qint64 *pid)
{
    qDebug() << "Opening file" << path << "using" << application;
#if defined(Q_OS_LINUX)
    // FIXME: the pid here is fake. So if something depends on it, it will likely misbehave
    return IndirectOpen([&]()
    {
        return QProcess::startDetached(application, QStringList() << path, workingDirectory);
    }, pid);
#else
    return QProcess::startDetached(application, QStringList() << path, workingDirectory, pid);
#endif
}

bool run(const QString &application, const QStringList &args, const QString &workingDirectory, qint64 *pid)
{
    qDebug() << "Running" << application << "with args" << args.join(' ');
#if defined(Q_OS_LINUX)
    // FIXME: the pid here is fake. So if something depends on it, it will likely misbehave
    return IndirectOpen([&]()
    {
        return QProcess::startDetached(application, args, workingDirectory);
    }, pid);
#else
    return QProcess::startDetached(application, args, workingDirectory, pid);
#endif
}

bool openUrl(const QUrl &url)
{
    qDebug() << "Opening URL" << url.toString();
    auto f = [&]()
    {
        return QDesktopServices::openUrl(url);
    };
#if defined(Q_OS_LINUX)
    return IndirectOpen(f);
#else
    return f();
#endif
}

}