Excel files with inlineStr cell types parsed as None instead of actual value in read only mode

See https://github.com/kz26/PyExcelerate/issues/34#issuecomment-65230703 for reference.

Expected cell values should be "col1", "col2", "col3" but iterating over the row returns None, None, None instead.

Example file attached - works fine in Excel 2013.

See p1598 of the ECMA OOXML reference, Part 1, 4th Edition for correct inlineStr semantics.

It's worth noting that the issue only affects workbooks opened with read_only=True. Unfortunately, inlineStr is one of the shittiest parts of the specification and can count as an optimisation artefact and one which we will probably never fully support. I can understand it's appeal for PyExcelerate and any other libraries that just want to stream but it does make interoperability a lot harder. It specifically makes lazy loading, as done in read-only mode, slower.

Issue #388 was marked as a duplicate of this issue.

Removing version: 2.1.x (automated comment)

Complete support for cells with inline strings in read-only mode.
Resolves #386.

→ <<cset cdf7a3aacfa7>>

Great to see that this one has already been fixed!

I ran into it with v2.3.4 while trying to read a giganterific sheet written with xlsxwriter in constant_memory mode. (@CharlieC had suggested using xlsxwriter as a workaround on #196.)