char: Clean up fragile use of error_is_set()

Using error_is_set(ERRP) to find out whether a function failed is
either wrong, fragile, or unnecessarily opaque.  It's wrong when ERRP
may be null, because errors go undetected when it is.  It's fragile
when proving ERRP non-null involves a non-local argument.  Else, it's
unnecessarily opaque (see commit 84d18f0).

The error_is_set(errp) in qemu_chr_new_from_opts() is merely fragile,
because the callers never pass a null errp argument.

Make the code more robust and more obviously correct: receive the
error in a local variable, then propagate it through the parameter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Markus Armbruster 2014-05-19 18:57:35 +02:00 committed by Gerd Hoffmann
parent 5f758366c0
commit 0aff637e92

View file

@ -3204,6 +3204,7 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
void (*init)(struct CharDriverState *s),
Error **errp)
{
Error *local_err = NULL;
CharDriver *cd;
CharDriverState *chr;
GSList *i;
@ -3245,8 +3246,9 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
chr = NULL;
backend->kind = cd->kind;
if (cd->parse) {
cd->parse(opts, backend, errp);
if (error_is_set(errp)) {
cd->parse(opts, backend, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto qapi_out;
}
}