It saves a bit of space on disk and deters novice users from tampering them. PR #22211.
PR #21016.
PR #19576.
It now guards against reading infinite files such as `/dev/zero`. And most readings are bound with a (lax) limit. As a side effect, more checking are done when reading a file and overall the reading procedure is more robust. PR #19095.
PR #17227.
PR #16357.