The previous code only ran cleanup (lock release for example) on SIGINT. For
anyone running restic in a container, the signal is going to be SIGTERM which
means containerized execution would leave locks behind.
While this could be addressed via interposing dumb-init to translate the signal,
a `kill` invocation is going to default to SIGTERM, so the same problem exists
for non container users.
Signed-off-by: Brian Harring <ferringb@gmail.com>
The builtin mechanism to capture a stacktrace in Go is to send a SIGQUIT
to the running process. However, this mechanism is not avaiable on
Windows. Thus, tweak the SIGINT handler to dump a stacktrace if the
environment variable `RESTIC_DEBUG_STACKTRACE_SIGINT` is set.
* PrintProgress no longer does unnecessary Sprintf calls, and performs
fewer allocations in general
* newProgressMax's callback checks whether the terminal supports
line updates once instead of once per call
* the callback looks up the terminal width once per call instead of
twice (on Windows)
* the status shortening now uses the Unicode-aware version from
internal/ui/termstatus (future-proofing)
cmd/restic/globals.go already provides Printf, Println and Warnf wrapper
which get their output streams from the globalOptions object. This
allows for stream replacements when testing.
