This removes logic from the decompressor for skipping tar archives. This
logic was originally added under the assumption that we probably want to
avoid the cost of reading them. However, this is generally inconsistent
with how ripgrep treats files like tar archives: it should search them
and do binary detection like normal.
Fixes#918
This commit adds opt-in support for searching compressed files during
recursive search. This behavior is only enabled when the
`-z/--search-zip` flag is passed to ripgrep. When enabled, a limited set
of common compression formats are recognized via file extension, and a
new process is spawned to perform the decompression. ripgrep then
searches the stdout of that spawned process.
Closes#539
