`requests.Response.content` reads the body lazily, so chunked-decode,
gzip-decode, and mid-stream connection drops all surface as
RequestException subclasses on first access -- not from requests.get
itself. The previous code accessed `.content` outside the surrounding
try/except, so any of those (rare but real) errors would propagate
out of download_content instead of falling back to the cached file
or raising the user-friendly cv.Invalid.
Move `data = req.content` inside the try block so the existing error
path handles it. Two new tests cover the with-cache and no-cache
branches using a `ChunkedEncodingError` injected on `.content`.
J. Nick Koston
24a3c2202f