I'll open with the background, then ask my question after.
I am modifying a list view for a SP 2010 list. I use an XSLT template for a field. I select this row, then implement a choice. When a certain condition is not met, the template performs the standard selection (which displays that field's normal content). Otherwise, I select the value of a different field (not normally shown in the view) and insert that into the display instead.
In SPD 2010, everything renders correctly. In my browser, however, the otherwise path (inserting the second field's value into the first field) does not appear to work -- the alternate field's content is not written to the DOM, it's simply skipped.
There are no errors thrown in the browser, and there are no HTML incompatibility errors listed by SPD around that part of the page. Failure exists in multiple browsers.
I've looked for a previous location that this template is called (I've edited an existing template that normally drew the cell for all rows, which is why it works for the alternate field content), but cannot find it being called before the point where I edited it. So, I don't believe that there is a condition for firing the template that I'm missing.
My question is, what next steps would you take to troubleshoot the problem? Specifically, do you know of a gremlin that would fail to generate errors, but still result in XSLT being rendered differently in SPD vs a browser window?
I get the feeling it's something to do with SPD assuming a field is included vs a browser requiring it explicitly declared, but I'm not certain where I would ascertain that.