[Qemu-devel] [PATCH] monitor: report entirety of hmp command on error

[Collin Walling <walling@linux.ibm.com>]

When a user incorrectly provides an hmp command, an error response will be 
printed that prompts the user to try "help <command name>". However, when
the command contains multiple parts e.g. "info skeys", only the last 
whitespace delimited string will be reported (in this example "info" will 
be dropped and the message will read "Try "help skeys" for more information",
which is incorrect).

Let's correct this by capturing the full name of the command as we recurse 
through the function monitor_parse_command.

Reported-by: Mikhail Fokin <fokin@de.ibm.com>
Signed-off-by: Collin Walling <walling@linux.ibm.com>
---
 monitor.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/monitor.c b/monitor.c
index 39f8ee1..d4844b4 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2964,7 +2964,8 @@ static const mon_cmd_t *search_dispatch_table(const mon_cmd_t *disp_table,
 static const mon_cmd_t *monitor_parse_command(Monitor *mon,
                                               const char *cmdp_start,
                                               const char **cmdp,
-                                              mon_cmd_t *table)
+                                              mon_cmd_t *table,
+                                              char *fullname)
 {
     const char *p;
     const mon_cmd_t *cmd;
@@ -2987,10 +2988,14 @@ static const mon_cmd_t *monitor_parse_command(Monitor *mon,
         p++;
     }
 
+    strncat(fullname, cmdname, strlen(cmdname));
+
     *cmdp = p;
     /* search sub command */
     if (cmd->sub_table != NULL && *p != '\0') {
-        return monitor_parse_command(mon, cmdp_start, cmdp, cmd->sub_table);
+        strncat(fullname, " ", 1);
+        return monitor_parse_command(mon, cmdp_start, cmdp, cmd->sub_table,
+                                     fullname);
     }
 
     return cmd;
@@ -3371,10 +3376,12 @@ static void handle_hmp_command(Monitor *mon, const char *cmdline)
 {
     QDict *qdict;
     const mon_cmd_t *cmd;
+    char fullname[256];
 
     trace_handle_hmp_command(mon, cmdline);
 
-    cmd = monitor_parse_command(mon, cmdline, &cmdline, mon->cmd_table);
+    cmd = monitor_parse_command(mon, cmdline, &cmdline, mon->cmd_table,
+                                fullname);
     if (!cmd) {
         return;
     }
@@ -3382,7 +3389,7 @@ static void handle_hmp_command(Monitor *mon, const char *cmdline)
     qdict = monitor_parse_arguments(mon, &cmdline, cmd);
     if (!qdict) {
         monitor_printf(mon, "Try \"help %s\" for more information\n",
-                       cmd->name);
+                       fullname);
         return;
     }
 
-- 
2.7.4