[PATCH v4 1/3] show: don't use hex literals in JSON output

[Thomas Jost]

On Fri, 20 Jan 2012 07:55:03 -0400, David Bremner <david at tethera.net> wrote:
> On Fri, 20 Jan 2012 10:39:23 +0100, Thomas Jost <schnouki at schnouki.net> wrote:
> > JSON does not support hex literals (0x..) so numbers must be formatted as %d
> > instead of %x.
> > ---
> >  notmuch-show.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
>  
> Probably I'm just being lazy here, but can you explain why this change
> does not require a corresponding change on the emacs side?

Because Emacs already does the right thing. JSON numbers are supposed to
be decimal only (see http://json.org/: digits are 0-9 only), but the
current code could result in displaying a hexadecimal number instead
("c" instead of "12"). This would then trigger an error in Emacs, or in
any other correct JSON parser.

However we are quite lucky: because of the possible values of the gmime
error codes, such an error cannot happen.

The most common gmime error codes are 1 (expired signature), 2 (no
public key), 4 (expired key) and 8 (revoked key). The other possible
value is 16 (unsupported algorithm) but obviously it is much more rare.
If this happens, the current code will add '"errors": 10' (hex for
16...). This is valid JSON (it looks like a decimal number) but it is
incorrect (should be 16, not 10).

With this patch, notmuch will correctly display '"errors": 16' if such a
case happens.

(By the way, this issue was spotted by Austin Clements in
id:"20120117034714.GG16740 at mit.edu", so he deserves the credits :))

Regards,

-- 
Thomas/Schnouki
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