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/base_hash.c b/fitz/base_hash.c
index e6ed019b..624cc305 100644
--- a/fitz/base_hash.c
+++ b/fitz/base_hash.c
@@ -177,7 +177,7 @@ fz_resize_hash(fz_context *ctx, fz_hash_table *table, int newsize)
 		}
 	}
 	if (newents == NULL)
-		fz_throw(ctx, "hash table resize failed; out of memory (%d entries)", newsize);
+		fz_throw(ctx, FZ_ERROR_GENERIC, "hash table resize failed; out of memory (%d entries)", newsize);
 	table->ents = newents;
 	memset(table->ents, 0, sizeof(fz_hash_entry) * newsize);
 	table->size = newsize;