Some questions and comments about this page (http://wix.sourceforge.net/manual-wix2/patch_building.htm):
1) In step 2, my WSX file does not have the Id property, which I believe means that it will automatically be regenerated on each build. It would be helpful to document that possiblity, or specify if that is somehow invalid in this context.
2) In step 5, shouldn't the schema be 2006?
3) I am confused (being a newbie with WIX) with an apparent conflict between step 5, where you CREATE a .PCP file, and step 6, where the same file (I THINK) is listed as the OUTPUT for the light linker.
4) It would help me at least if there were a lot more detail in step 6, or references to other samples and documentation. For instance, my WIX setup is generated by Indigo Rose MSI Factory, which generates several WSX files. ALL the WSX files in your project need to be included in the compiler and linker lines.
I was attracted to this as potentially a way to automate building a real .MSI of a full installer for a 1.0.1 version of a product, doing the admin install, and then building a 1.0.1 PATCH that could be used by customers to upgrade a 1.0.0 installation to 1.0.1. From the errors I get from the linker, I think that this is actually NOT possible, even if your setup is built from a hand-edited WSX file, and even though it seems like a very obvious thing to want to make part of an automated build. Perhaps that's another tutorial. how-to or manual page, but it seems to me that it should be covered by this page.