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, 9 insertions, 10 deletions

diff --git a/util/qemu-option.c b/util/qemu-option.c
index 95f242ea0e..fda4e5fcbf 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -799,17 +799,16 @@ static void opts_do_parse(QemuOpts *opts, const char *params,
     }
 }
 
-int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname)
+/**
+ * Store options parsed from @params into @opts.
+ * If @firstname is non-null, the first key=value in @params may omit
+ * key=, and is treated as if key was @firstname.
+ * On error, store an error object through @errp if non-null.
+ */
+void qemu_opts_do_parse(QemuOpts *opts, const char *params,
+                       const char *firstname, Error **errp)
 {
-    Error *err = NULL;
-
-    opts_do_parse(opts, params, firstname, false, &err);
-    if (err) {
-        qerror_report_err(err);
-        error_free(err);
-        return -1;
-    }
-    return 0;
+    opts_do_parse(opts, params, firstname, false, errp);
 }
 
 static QemuOpts *opts_parse(QemuOptsList *list, const char *params,