What torch.exe compares in wixpdb files for files without version

I am creating patches for my installation using "purely wix" method.

When I check created msp file against base msi file using Orca some of the changed files are not selected for patching. For example I have a txt file in which all 0 are replaced wit开发者_如何学运维h 1. Old and new file are the same size but in Orca their MsiFileHash entries are completely different. I checked another txt file which is selected for patching and only difference is that it's size has changed.

Is file size only rule of comparison when torch compares rows for unversioned files? I thought that torch compares database rows and if it finds some difference it selects that row for patching.

Could somebody post a link or explanation of the rules torch.exe applies when comparing database rows for both versioned and unversioned files. Thanks in advance.

This is the normal behavior. Patches include only files which have a different size or version. This is because File table has columns only for Size and Version, it doesn't contain hash or file content information.

So if you want to include a file in a MSP patch, you need to change its size or increase its version.