activescott/lessmsi

FilesToExtract Count Can Be Incorrect When Installer Contains Multiple CAB Files

hexxellor opened this issue · 4 comments

hexxellor commented

In the code a new ExtractionProgress object is created in Wixtracts.cs like this:
progress = new ExtractionProgress(progressCallback, filesToExtract.Length);

However, this assumes it should set the progress bar maximum value to "filesToExtract.Length"

The problem with this is if the MSI contains multiple CAB files with varying amounts of files in each (some being duplicates), the total can be incorrect.

The correct total can actually be obtained later on in the same source code where it's parsing/merging the CAB files. Something similar to this would work:

public static void ExtractFiles(Path msi, string outputDir, MsiFile[] filesToExtract, AsyncCallback progressCallback)
{
'REMOVED ORIGINAL CODE FOR CLARITY
                int realTotalFilesToExtract = 0;
	        try
                {
	            foreach (MSCabinet decompressor in cabDecompressors)
	            {
	                realTotalFilesToExtract += decompressor.GetFiles().Count();
	            }
                }
                '...
'REMOVED FOLLOWING CODE FOR CLARITY
}

I'm not suggesting you use this exact code. Besides being pretty crude it's also obvious at this point in the code the ExtractionProgress object has already been created and the total number of files set (incorrectly). So this chunk of code would need to be reworked to fix this.

An example MSI with this issue is here:
https://github.com/hexxellor/TemporaryJunk/raw/master/LessMSI%20Issue/Example%20MSI%20With%20Multiple%20CABs.zip

If you need this file, please grab it and keep a copy right away. I can't promise I'll be hosting it for more a month (after January 7th, 2019).

Thanks.

activescott commented

Thanks for the report! I really appreciate it. I'd love it if you wanted to submit a PR. Let me know if you plan to or not.

hexxellor commented

Thanks for hosting the file so I can remove mine. I will take a look at it if I can get the time, but from what I recall the way it was written will require some big changes so it just comes down to how long it'll take. If I can find an elegant quick fix I'll submit a PR.

  • 👍1
miles192 commented

I also see this issue in our terrible installer files.
Quick fix is to limit the progress value to the max value. It gets to 100% too early but doesn't crash out.

  • 👍1