On Fri, Feb 2, 2018 at 4:25 AM, Duy Nguyen <pclouds@xxxxxxxxx> wrote:
> On Wed, Jan 31, 2018 at 02:59:32PM -0800, Junio C Hamano wrote:
>> Eric Sunshine <sunshine@xxxxxxxxxxxxxx> writes:
>> > On Wed, Jan 31, 2018 at 4:30 AM, Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx> wrote:
>> >> + len = strbuf_read_file(&sb, am_path(state, msgnum(state)), 0);
>> >> + if (len < 0)
>> >> + die_errno(_("failed to read '%s'"),
>> >> + am_path(state, msgnum(state)));
>> >
>> > Isn't this am_path() invocation inside die_errno() likely to clobber
>> > the 'errno' from strbuf_read_file() which you want to be reporting?
>> True.
>
> Thanks both. Good catch. Of course I will fix this in the re-roll, but
> should we also do something for the current code base with the
> following patch?
>
> - die_errno(_("could not read '%s'"), am_path(state, file));
> + saved_errno = errno;
> + path = am_path(state, file);
> + errno = saved_errno;
> + die_errno(_("could not read '%s'"), path);
Rather than worrying about catching these at review time, I had been
thinking about a solution which automates it using variadic macros.
Something like:
#define die_errno(...) do { \
int saved_errno_ = errno; \
die_errno_(saved_errno_, __VA_ARGS__); \
} while (0);
