[PATCH] status: store format option as an int

[Jonathan Nieder <jrnieder@gmail.com>]

It is unsafe to pass a pointer to a value of enumerated type to
OPT_SET_INT (as v1.7.0-rc0~137^2~14, 2009-0905) does, since it might
have the wrong alignment or width (C99 only says "Each enumerated type
shall be compatible with char, a signed integer type, or an unsigned
integer type.  The choice of type is implementation-defined, but shall
be capable of representing the values of all the members of the
enumeration.)

Probably this didn't come up in practice because by default GCC uses
an 'int' to represent small enums unless passed -fshort-enums (except
on certain architectures where -fshort-enums is the default).

Noticed-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Jeff King wrote:

> Hmm. That does work (with either option, or both), but it is somewhat of
> an accident. There is an enum specifying the format the user wants. We
> hand it to parse-options for those options, telling it that the value is
> an int.

Yikes.  That's an accident waiting to happen.  How about this, to start?

 builtin/commit.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index 6e32166..b28848d 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -94,11 +94,12 @@ static const char *only_include_assumed;
 static struct strbuf message;
 
 static int null_termination;
-static enum {
-	STATUS_FORMAT_LONG,
+enum status_format {
+	STATUS_FORMAT_LONG = 0,
 	STATUS_FORMAT_SHORT,
 	STATUS_FORMAT_PORCELAIN
-} status_format = STATUS_FORMAT_LONG;
+};
+static int status_format;
 static int status_show_branch;
 
 static int opt_parse_m(const struct option *opt, const char *arg, int unset)
-- 
1.7.5.rc2