qemu-img: Suppress unhelpful extra errors in convert, amend

img_convert() and img_amend() use qemu_opts_do_parse(), which reports
errors with qerror_report_err().  Its error messages aren't helpful
here, the caller reports one that actually makes sense.  Reproducer:

    $ qemu-img convert -o backing_format=raw in.img out.img
    qemu-img: Invalid parameter 'backing_format'
    qemu-img: Invalid options for file format 'raw'

To fix, propagate errors through qemu_opts_do_parse().  This lifts the
error reporting into callers.  Drop it from img_convert() and
img_amend(), keep it in qemu_chr_parse_compat(), bdrv_img_create().

Since I'm touching qemu_opts_do_parse() anyway, write a function
comment for it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/qemu/option.h b/include/qemu/option.h
index a41ee92508..f88b545dfc 100644
--- a/include/qemu/option.h
+++ b/include/qemu/option.h
@@ -115,7 +115,8 @@ const char *qemu_opts_id(QemuOpts *opts);
 void qemu_opts_set_id(QemuOpts *opts, char *id);
 void qemu_opts_del(QemuOpts *opts);
 void qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp);
-int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname);
+void qemu_opts_do_parse(QemuOpts *opts, const char *params,
+                        const char *firstname, Error **errp);
 QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, int permit_abbrev);
 void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
                             int permit_abbrev);