Exception handling changes

In preparation for work on progressive loading, update the exception
handling scheme slightly.

Until now, exceptions (as thrown with fz_throw, and caught with
fz_try/fz_catch) have merely had an informative string. They have
never had anything that can be compared to see if an error is of
a particular type.

We now introduce error codes; when we fz_throw, we now always
give an error code, and can optionally (using fz_throw_message)
give both an error code and an informative string.

When we fz_rethrow from within a fz_catch, both the error code and
the error message is maintained. Using fz_rethrow_message we can
'improve' the error message, but the code is maintained.

The error message can be read out using fz_caught_message() and the
error code can be read as fz_caught().

Currently we only define a 'generic' error. This will expand in future
versions to include other error types that may be tested for.

1 files changed, 1 insertions, 1 deletions

diff --git a/fitz/crypt_pkcs7.c b/fitz/crypt_pkcs7.c
index 47f272a7..1bc50b6e 100644
--- a/fitz/crypt_pkcs7.c
+++ b/fitz/crypt_pkcs7.c
@@ -379,7 +379,7 @@ int pdf_check_signature(fz_context *ctx, pdf_document *doc, pdf_widget *widget,
 	fz_catch(ctx)
 	{
 		res = 0;
-		strncpy(ebuf, ctx->error->message, ebufsize);
+		strncpy(ebuf, fz_caught_message(ctx), ebufsize);
 	}
 
 	if (ebufsize > 0)