POSIX's `head` specification states: "The application shall ensure that the number option-argument is a positive decimal integer"
Negative values are supported on GNU `head`, so this works in the discourse docker image. However, in some environments (e.g. macOS), the system `head` version fails with a negative `n` parameter.
This commit does two things:
Checks the status at each stage of the pipe, so it cannot fail silently
Flip the `ls` command to list in descending time order, and use `tail -n +501` instead of `head -n -500`.
The visible result is that macOS users no longer see head: illegal line count -- -500 printed throughout the test suite.
Net::HTTP always returns ASCII-8BIT encoding. File.read auto-detects the encoding. This leads to an encoding inconsistency between a fresh download, and a cached download. This commit ensures all downloaded files are treated equally, by always returning the cached version from the filesystem, even during initial download.
One symptom of this problem is during theme exports: https://meta.discourse.org/t/116907
Related ruby ticket: https://bugs.ruby-lang.org/issues/2567
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
