CreateDownloadPage issue without content-length header

[Louis Vézina]

Hi everyone,

I'm just trying the new CreateDownloadPage function in 6.1.2 but I face an issue when trying to download a zip file from Github. They do not return the content-length header so Inno Setup is reporting -1. That fine until the download ends and throw this exception: `Exception: Invalid progress: 12316250 of -1`.

Is there anything I'm missing here? Anyway to prevent Inno from validating the size?

Here's my test case:

```

; -- CodeDownloadFiles.iss --

;

; This script shows how the CreateDownloadPage support function can be used to

; download temporary files while showing the download progress to the user.

[Setup]

AppName=My Program

AppVersion=1.5

WizardStyle=modern

DefaultDirName={autopf}\My Program

DefaultGroupName=My Program

UninstallDisplayIcon={app}\MyProg.exe

OutputDir=userdocs:Inno Setup Examples Output

[Files]

; Place any regular files here

//Source: "MyProg.exe"; DestDir: "{app}";

//Source: "MyProg.chm"; DestDir: "{app}";

//Source: "Readme.txt"; DestDir: "{app}"; Flags: isreadme;

; These files will be downloaded

Source: "{tmp}\bazarr.zip"; DestDir: "{app}"; Flags: external

[Icons]

Name: "{group}\My Program"; Filename: "{app}\MyProg.exe"

[Code]

var

  DownloadPage: TDownloadWizardPage;

function OnDownloadProgress(const Url, FileName: String; const Progress, ProgressMax: Int64): Boolean;

begin

  if Progress = ProgressMax then

    Log(Format('Successfully downloaded file to {tmp}: %s', [FileName]));

  Result := True;

end;

procedure InitializeWizard;

begin

  DownloadPage := CreateDownloadPage(SetupMessage(msgWizardPreparing), SetupMessage(msgPreparingDesc), @OnDownloadProgress);

end;

function NextButtonClick(CurPageID: Integer): Boolean;

begin

  if CurPageID = wpReady then begin

    DownloadPage.Clear;

    DownloadPage.Add('https://github.com/PowerShell/PowerShell/archive/master.zip', 'master.zip', '');

    DownloadPage.Show;

    try

      try

        DownloadPage.Download;

        Result := True;

      except

        SuppressibleMsgBox(AddPeriod(GetExceptionMessage), mbCriticalError, MB_OK, IDOK);

        Result := False;

      end;

    finally

      DownloadPage.Hide;

    end;

  end else

    Result := True;

end;
```

[Martijn Laan]

Op 14-3-2021 om 16:55 schreef Louis Vézina:

Anyway to prevent Inno from validating the size?

Use the third parameter to tell it the expected SHA256 hash and then it won't check the size because it checks the hash instead.

Greetings,
Martijn

[Louis Vézina]

Thanks for the answer. Unfortunately, as the file will get updated over time (in fact each time a new version is released), I can't specify the hash. Any other idea? Are you able to reproduce the issue?

[Martijn Laan]

Op 18-3-2021 om 11:31 schreef Louis Vézina:

Thanks for the answer. Unfortunately, as the file will get updated over time (in fact each time a new version is released), I can't specify the hash. Any other idea? Are you able to reproduce the issue?

Yes I can, but on the other hand it seems a bit odd / unsafe for an installer to allow the download of a file you basically know nothing about. IS is pretty paranoid about checkng the downloaded file for a reason.

Why are you downloading it as part of the install instead of by your application? How do you keep it up to date since it's an unstable file?

Greetings,
Martijn

[Louis Vézina]

I want to create an base installer (which will include WinPython and nssm) that will download the latest Github release of my python script. Currently I include the content of the Github release zip inside my installer but it means I have to update the installer from time to time and I would prefer to put my time into improving my program instead of packaging it over and over again. As I'm controlling the release process over Github, it doesn't sound unsafe to me. Thanks for your help BTW!

[Martijn Laan]

Op 21-3-2021 om 03:34 schreef Louis Vézina:

I want to create an base installer (which will include WinPython and nssm) that will download the latest Github release of my python script. Currently I include the content of the Github release zip inside my installer but it means I have to update the installer from time to time and I would prefer to put my time into improving my program instead of packaging it over and over again. As I'm controlling the release process over Github, it doesn't sound unsafe to me. Thanks for your help BTW!

Ok, in the next version the built-in download support allows the download of files for which the server does not specify the file size.

Greetings,
Martijn

[Louis Vézina]

Thanks, that's appreciated!

[Louis Vézina]

Any ETA for 6.1.3?