From 5f3745351f4df30b50b3a9693f0f617acb2476e8 Mon Sep 17 00:00:00 2001
From: Robert Knight <robertknight@gmail.com>
Date: Sun, 21 Aug 2011 21:51:29 +0100
Subject: [PATCH] Get launching of the main update installer process working in
 the case where elevation is not required.

 * Add ProcessUtils::currentProcessPath() to get the path to the current application
   and add a Linux implementation.
 * Implement ProcessUtils::runAsync() on Unix using fork/execve.
 * Setup updater to run the main installation phase with the correct arguments.
 * Add '.zip' to the package name to get the path of the package file.
---
 src/ProcessUtils.cpp    | 32 ++++++++++++++++++++++++++++++++
 src/ProcessUtils.h      |  2 ++
 src/UpdateInstaller.cpp | 13 +++++++++++--
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/ProcessUtils.cpp b/src/ProcessUtils.cpp
index 36d10f1..37e5825 100644
--- a/src/ProcessUtils.cpp
+++ b/src/ProcessUtils.cpp
@@ -1,10 +1,13 @@
 #include "ProcessUtils.h"
 
+#include "FileOps.h"
 #include "Platform.h"
 #include "StringUtils.h"
 #include "Log.h"
 
 #include <string.h>
+#include <vector>
+#include <iostream>
 
 #ifdef PLATFORM_WINDOWS
 #include <windows.h>
@@ -186,6 +189,25 @@ void ProcessUtils::runElevatedWindows(const std::string& executable,
 void ProcessUtils::runAsyncUnix(const std::string& executable,
 						const std::list<std::string>& args)
 {
+	if (fork() == 0)
+	{
+		// in child process
+		char** argBuffer = new char*[args.size() + 1];
+		argBuffer[0] = strdup(executable.c_str());
+		int i = 1;
+		for (std::list<std::string>::const_iterator iter = args.begin(); iter != args.end(); iter++)
+		{
+			argBuffer[i] = strdup(iter->c_str());
+			++i;
+		}
+		argBuffer[i] = 0;
+
+		if (execve(executable.c_str(),argBuffer,environ) == -1)
+		{
+			LOG(Error,"error starting child: " + std::string(strerror(errno)));
+			exit(1);
+		}
+	}
 }
 #endif
 
@@ -195,3 +217,13 @@ void ProcessUtils::runAsyncWindows(const std::string& executable,
 {
 }
 #endif
+		
+std::string ProcessUtils::currentProcessPath()
+{
+#ifdef PLATFORM_LINUX
+	std::string path = FileOps::canonicalPath("/proc/self/exe");
+	LOG(Info,"Current process path " + path);
+	return path;
+#endif
+}
+
diff --git a/src/ProcessUtils.h b/src/ProcessUtils.h
index 00a9ebc..9d3134e 100644
--- a/src/ProcessUtils.h
+++ b/src/ProcessUtils.h
@@ -6,6 +6,8 @@
 class ProcessUtils
 {
 	public:
+		static std::string currentProcessPath();
+
 		static void runAsync(const std::string& executable,
 		                     const std::list<std::string>& args);
 
diff --git a/src/UpdateInstaller.cpp b/src/UpdateInstaller.cpp
index 0582162..47865c7 100644
--- a/src/UpdateInstaller.cpp
+++ b/src/UpdateInstaller.cpp
@@ -51,8 +51,17 @@ void UpdateInstaller::run() throw ()
 		LOG(Info,"Waiting for main app process to finish");
 		ProcessUtils::waitForProcess(m_waitPid);
 
-		std::string updaterPath;
+		std::string updaterPath = ProcessUtils::currentProcessPath();
 		std::list<std::string> args;
+		args.push_back("--mode");
+		args.push_back("main");
+		args.push_back("--install-dir");
+		args.push_back(m_installDir);
+		args.push_back("--package-dir");
+		args.push_back(m_packageDir);
+		args.push_back("--script");
+		args.push_back(m_script->path());
+
 		if (!checkAccess())
 		{
 			LOG(Info,"Insufficient rights to install app to " + m_installDir + " requesting elevation");
@@ -140,7 +149,7 @@ void UpdateInstaller::revert()
 
 void UpdateInstaller::installFile(const UpdateScriptFile& file)
 {
-	std::string packageFile = m_installDir + '/' + file.package;
+	std::string packageFile = m_packageDir + '/' + file.package + ".zip";
 	std::string destPath = m_installDir + '/' + file.path;
 	std::string target = file.linkTarget;