annotate contrib/packaging/inno/modpath.iss @ 41847:0f49b56d5d74

inno: replace add_path.exe with a Pascal script

While attempting to build the Inno installer, I was unable to
find a copy of add_path.exe from the source site previously
listed in the docs.

Some quick Googling revealed that achieving this functionality
in native Pascal scripts seems to be preferred these days.

This commit vendors "Modify Path" (fetched from
https://www.legroom.net/software/modpath) and plugs it into
our Inno config file per its instructions.

The existing Inno installer appears to only modify PATH for
the current user (as opposed to at the system level). I've
maintained this behavior with Modify Path. Although it would
be trivial to change or add checkboxes to control the behavior.
I'll leave this as a follow-up.

Differential Revision: https://phab.mercurial-scm.org/D6060

// ----------------------------------------------------------------------------
//
// Inno Setup Ver:	5.4.2
// Script Version:	1.4.2
// Author:			Jared Breland <[e-mail]>
// Homepage:		http://www.legroom.net/software
// License:			GNU Lesser General Public License (LGPL), version 3
//						http://www.gnu.org/licenses/lgpl.html
//
// Script Function:
//	Allow modification of environmental path directly from Inno Setup installers
//
// Instructions:
//	Copy modpath.iss to the same directory as your setup script
//
//	Add this statement to your [Setup] section
//		ChangesEnvironment=true
//
//	Add this statement to your [Tasks] section
//	You can change the Description or Flags
//	You can change the Name, but it must match the ModPathName setting below
//		Name: modifypath; Description: &Add application directory to your environmental path; Flags: unchecked
//
//	Add the following to the end of your [Code] section
//	ModPathName defines the name of the task defined above
//	ModPathType defines whether the 'user' or 'system' path will be modified;
//		this will default to user if anything other than system is set
//	setArrayLength must specify the total number of dirs to be added
//	Result[0] contains first directory, Result[1] contains second, etc.
//		const
//			ModPathName = 'modifypath';
//			ModPathType = 'user';
//
//		function ModPathDir(): TArrayOfString;
//		begin
//			setArrayLength(Result, 1);
//			Result[0] := ExpandConstant('{app}');
//		end;
//		#include "modpath.iss"
// ----------------------------------------------------------------------------

procedure ModPath();
var
	oldpath:	String;
	newpath:	String;
	updatepath:	Boolean;
	pathArr:	TArrayOfString;
	aExecFile:	String;
	aExecArr:	TArrayOfString;
	i, d:		Integer;
	pathdir:	TArrayOfString;
	regroot:	Integer;
	regpath:	String;

begin
	// Get constants from main script and adjust behavior accordingly
	// ModPathType MUST be 'system' or 'user'; force 'user' if invalid
	if ModPathType = 'system' then begin
		regroot := HKEY_LOCAL_MACHINE;
		regpath := 'SYSTEM\CurrentControlSet\Control\Session Manager\Environment';
	end else begin
		regroot := HKEY_CURRENT_USER;
		regpath := 'Environment';
	end;

	// Get array of new directories and act on each individually
	pathdir := ModPathDir();
	for d := 0 to GetArrayLength(pathdir)-1 do begin
		updatepath := true;

		// Modify WinNT path
		if UsingWinNT() = true then begin

			// Get current path, split into an array
			RegQueryStringValue(regroot, regpath, 'Path', oldpath);
			oldpath := oldpath + ';';
			i := 0;

			while (Pos(';', oldpath) > 0) do begin
				SetArrayLength(pathArr, i+1);
				pathArr[i] := Copy(oldpath, 0, Pos(';', oldpath)-1);
				oldpath := Copy(oldpath, Pos(';', oldpath)+1, Length(oldpath));
				i := i + 1;

				// Check if current directory matches app dir
				if pathdir[d] = pathArr[i-1] then begin
					// if uninstalling, remove dir from path
					if IsUninstaller() = true then begin
						continue;
					// if installing, flag that dir already exists in path
					end else begin
						updatepath := false;
					end;
				end;

				// Add current directory to new path
				if i = 1 then begin
					newpath := pathArr[i-1];
				end else begin
					newpath := newpath + ';' + pathArr[i-1];
				end;
			end;

			// Append app dir to path if not already included
			if (IsUninstaller() = false) AND (updatepath = true) then
				newpath := newpath + ';' + pathdir[d];

			// Write new path
			RegWriteStringValue(regroot, regpath, 'Path', newpath);

		// Modify Win9x path
		end else begin

			// Convert to shortened dirname
			pathdir[d] := GetShortName(pathdir[d]);

			// If autoexec.bat exists, check if app dir already exists in path
			aExecFile := 'C:\AUTOEXEC.BAT';
			if FileExists(aExecFile) then begin
				LoadStringsFromFile(aExecFile, aExecArr);
				for i := 0 to GetArrayLength(aExecArr)-1 do begin
					if IsUninstaller() = false then begin
						// If app dir already exists while installing, skip add
						if (Pos(pathdir[d], aExecArr[i]) > 0) then
							updatepath := false;
							break;
					end else begin
						// If app dir exists and = what we originally set, then delete at uninstall
						if aExecArr[i] = 'SET PATH=%PATH%;' + pathdir[d] then
							aExecArr[i] := '';
					end;
				end;
			end;

			// If app dir not found, or autoexec.bat didn't exist, then (create and) append to current path
			if (IsUninstaller() = false) AND (updatepath = true) then begin
				SaveStringToFile(aExecFile, #13#10 + 'SET PATH=%PATH%;' + pathdir[d], True);

			// If uninstalling, write the full autoexec out
			end else begin
				SaveStringsToFile(aExecFile, aExecArr, False);
			end;
		end;
	end;
end;

// Split a string into an array using passed delimeter
procedure MPExplode(var Dest: TArrayOfString; Text: String; Separator: String);
var
	i: Integer;
begin
	i := 0;
	repeat
		SetArrayLength(Dest, i+1);
		if Pos(Separator,Text) > 0 then	begin
			Dest[i] := Copy(Text, 1, Pos(Separator, Text)-1);
			Text := Copy(Text, Pos(Separator,Text) + Length(Separator), Length(Text));
			i := i + 1;
		end else begin
			 Dest[i] := Text;
			 Text := '';
		end;
	until Length(Text)=0;
end;


procedure CurStepChanged(CurStep: TSetupStep);
var
	taskname:	String;
begin
	taskname := ModPathName;
	if CurStep = ssPostInstall then
		if IsTaskSelected(taskname) then
			ModPath();
end;

procedure CurUninstallStepChanged(CurUninstallStep: TUninstallStep);
var
	aSelectedTasks:	TArrayOfString;
	i:				Integer;
	taskname:		String;
	regpath:		String;
	regstring:		String;
	appid:			String;
begin
	// only run during actual uninstall
	if CurUninstallStep = usUninstall then begin
		// get list of selected tasks saved in registry at install time
		appid := '{#emit SetupSetting("AppId")}';
		if appid = '' then appid := '{#emit SetupSetting("AppName")}';
		regpath := ExpandConstant('Software\Microsoft\Windows\CurrentVersion\Uninstall\'+appid+'_is1');
		RegQueryStringValue(HKLM, regpath, 'Inno Setup: Selected Tasks', regstring);
		if regstring = '' then RegQueryStringValue(HKCU, regpath, 'Inno Setup: Selected Tasks', regstring);

		// check each task; if matches modpath taskname, trigger patch removal
		if regstring <> '' then begin
			taskname := ModPathName;
			MPExplode(aSelectedTasks, regstring, ',');
			if GetArrayLength(aSelectedTasks) > 0 then begin
				for i := 0 to GetArrayLength(aSelectedTasks)-1 do begin
					if comparetext(aSelectedTasks[i], taskname) = 0 then
						ModPath();
				end;
			end;
		end;
	end;
end;

function NeedRestart(): Boolean;
var
	taskname:	String;
begin
	taskname := ModPathName;
	if IsTaskSelected(taskname) and not UsingWinNT() then begin
		Result := True;
	end else begin
		Result := False;
	end;
end;