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 <arm...@redhat.com>
---
qemu-char.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/qemu-char.c b/qemu-char.c
index 3eaefc9..5a7975f 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -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;
}
}
--
1.9.0
