GH-1389 wrap QDesktopServices and QProcess::startDetached

Essentially do not pass some environment variables to subprocesses:
* LD_PRELOAD
* LD_LIBRARY_PATH
* LD_DEBUG
* QT_PLUGIN_PATH
* QT_FONTPATH

logic/CMakeLists.txt

@@ -32,8 +32,12 @@ set(LOGIC_SOURCES
 	# JSON parsing helpers
 	Json.h
 	Json.cpp
+
 	FileSystem.h
 	FileSystem.cpp
+	DesktopServices.h
+	DesktopServices.cpp
+
 	Exception.h
 
 	# RW lock protected map

logic/DesktopServices.cpp

@@ -0,0 +1,149 @@
+#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
+}
+
+}

logic/DesktopServices.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <QUrl>
+#include <QString>
+#include "multimc_logic_export.h"
+
+/**
+ * This wraps around QDesktopServices and adds workarounds where needed
+ * Use this instead of QDesktopServices!
+ */
+namespace DesktopServices
+{
+	/**
+	 * Open a file in whatever application is applicable
+	 */
+	MULTIMC_LOGIC_EXPORT bool openFile(const QString &path);
+
+	/**
+	 * Open a file in the specified application
+	 */
+	MULTIMC_LOGIC_EXPORT bool openFile(const QString &application, const QString &path, const QString & workingDirectory = QString(), qint64 *pid = 0);
+
+	/**
+	 * Run an application
+	 */
+	MULTIMC_LOGIC_EXPORT bool run(const QString &application,const QStringList &args, const QString & workingDirectory = QString(), qint64 *pid = 0);
+
+	/**
+	 * Open a directory
+	 */
+	MULTIMC_LOGIC_EXPORT bool openDirectory(const QString &path, bool ensureExists = false);
+
+	/**
+	 * Open the URL, most likely in a browser. Maybe.
+	 */
+	MULTIMC_LOGIC_EXPORT bool openUrl(const QUrl &url);
+};

logic/FileSystem.cpp

@@ -6,8 +6,8 @@
 #include <QSaveFile>
 #include <QFileInfo>
 #include <QDebug>
-#include <QDesktopServices>
 #include <QUrl>
+#include <QStandardPaths>
 
 namespace FS {
 
@@ -304,22 +304,6 @@ QString DirNameFromString(QString string, QString inDir)
 	return dirName;
 }
 
-void openDirInDefaultProgram(QString path, bool ensureExists)
-{
-	QDir parentPath;
-	QDir dir(path);
-	if (!dir.exists())
-	{
-		parentPath.mkpath(dir.absolutePath());
-	}
-	QDesktopServices::openUrl(QUrl::fromLocalFile(dir.absolutePath()));
-}
-
-void openFileInDefaultProgram(QString filename)
-{
-	QDesktopServices::openUrl(QUrl::fromLocalFile(filename));
-}
-
 // Does the directory path contain any '!'? If yes, return true, otherwise false.
 // (This is a problem for Java)
 bool checkProblemticPathJava(QDir folder)
@@ -449,4 +433,4 @@ bool createShortCut(QString location, QString dest, QStringList args, QString na
 	return false;
 #endif
 }
-}
+}

logic/FileSystem.h

@@ -110,12 +110,6 @@ MULTIMC_LOGIC_EXPORT QString RemoveInvalidFilenameChars(QString string, QChar re
 
 MULTIMC_LOGIC_EXPORT QString DirNameFromString(QString string, QString inDir = ".");
 
-/// Opens the given file in the default application.
-MULTIMC_LOGIC_EXPORT void openFileInDefaultProgram(QString filename);
-
-/// Opens the given directory in the default application.
-MULTIMC_LOGIC_EXPORT void openDirInDefaultProgram(QString dirpath, bool ensureExists = false);
-
 /// Checks if the a given Path contains "!"
 MULTIMC_LOGIC_EXPORT bool checkProblemticPathJava(QDir folder);
 

logic/tools/MCEditTool.cpp

@@ -2,7 +2,6 @@
 
 #include <QDir>
 #include <QProcess>
-#include <QDesktopServices>
 #include <QUrl>
 // FIXME: mixing logic and UI!!!!
 #include <QInputDialog>
@@ -11,6 +10,7 @@
 #include "settings/SettingsObject.h"
 #include "BaseInstance.h"
 #include "minecraft/MinecraftInstance.h"
+#include <DesktopServices.h>
 
 MCEditTool::MCEditTool(SettingsObjectPtr settings, InstancePtr instance, QObject *parent)
 	: BaseDetachedTool(settings, instance, parent)
@@ -84,7 +84,7 @@ void MCEditTool::runImpl()
 	#endif
 	if(program.size())
 	{
-		QProcess::startDetached(program, QStringList() << save, mceditPath);
+		DesktopServices::openFile(program, save, mceditPath);
 	}
 #endif
 }