[PATCH 7/9] ui: Improve "change vnc" error reporting

[Markus Armbruster]

Switch from monitor_printf() to error_setg() and hmp_handle_error().
This makes "this is an error" more obvious both in the source and in
the monitor, where hmp_handle_error() prefixes the message with
"Error: ".

Signed-off-by: Markus Armbruster <arm...@redhat.com>
---
 monitor/hmp-cmds.c |  8 ++++----
 ui/ui-hmp-cmds.c   | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index f0f7b74fb3..8542eee3d4 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1209,9 +1209,8 @@ void hmp_change(Monitor *mon, const QDict *qdict)
 #ifdef CONFIG_VNC
     if (strcmp(device, "vnc") == 0) {
         if (read_only) {
-            monitor_printf(mon,
-                           "Parameter 'read-only-mode' is invalid for VNC\n");
-            return;
+            error_setg(&err, "Parameter 'read-only-mode' is invalid for VNC");
+            goto end;
         }
         if (strcmp(target, "passwd") == 0 ||
             strcmp(target, "password") == 0) {
@@ -1223,7 +1222,8 @@ void hmp_change(Monitor *mon, const QDict *qdict)
                 qmp_change_vnc_password(arg, &err);
             }
         } else {
-            monitor_printf(mon, "Expected 'password' after 'vnc'\n");
+            error_setg(&err, "Expected 'password' after 'vnc'");
+            goto end;
         }
     } else
 #endif
diff --git a/ui/ui-hmp-cmds.c b/ui/ui-hmp-cmds.c
index af290da9e1..90a4f86f25 100644
--- a/ui/ui-hmp-cmds.c
+++ b/ui/ui-hmp-cmds.c
@@ -270,6 +270,28 @@ out:
     hmp_handle_error(mon, err);
 }
 
+void hmp_change_vnc(Monitor *mon, const char *device, const char *target,
+                    const char *arg, const char *read_only, bool force,
+                    Error **errp)
+{
+    if (read_only) {
+        error_setg(mon, "Parameter 'read-only-mode' is invalid for VNC");
+        return;
+    }
+    if (strcmp(target, "passwd") == 0 ||
+        strcmp(target, "password") == 0) {
+        if (!arg) {
+            MonitorHMP *hmp_mon = container_of(mon, MonitorHMP, common);
+            monitor_read_password(hmp_mon, hmp_change_read_arg, NULL);
+            return;
+        } else {
+            qmp_change_vnc_password(arg, &err);
+        }
+    } else {
+        monitor_printf(mon, "Expected 'password' after 'vnc'\n");
+    }
+}
+
 void hmp_sendkey(Monitor *mon, const QDict *qdict)
 {
     const char *keys = qdict_get_str(qdict, "keys");
-- 
2.37.3