nmcli: allow cmd specific option parsing in next_arg() func

Options dependant on specific commands (e.g., nmcli connection show
--active) are now allowed to be processed by the next_arg() function.
This would allow autocompletion to expand options belonging to specific
command first, and then global ones.

Note that global options ("--ask" and "--show-secrets") will be auto-completed
everywhere but only if at least a '-' is passed. Command specific ones
(--temporary, --active, --order) will be auto-completed only after the command
they belongs to but without requiring the user to pass a heading '-'.

Example:
'nmcli connection show -a'
will expand '-a' into '--active', but
'nmcli connection add -a`
will expand '-a' into '--ask' (as it is a global option)

This commit fixes also autocompletion for:
nmcli connection modify --temporary

(cherry picked from commit 6a3d77fbe6)

clients/cli/utils.c

@@ -51,21 +51,66 @@ parse_global_arg (NmCli *nmc, const char *arg)
 
 	return TRUE;
 }
-
+/**
+ * next_arg:
+ * @nmc: NmCli data
+ * @*argc: pointer to left number of arguments to parse
+ * @***argv: pointer to const char *array of arguments still to parse
+ * @...: a %NULL terminated list of cmd options to match (e.g., "--active")
+ *
+ * Takes care of autocompleting options when needed and performs
+ * match against passed options while moving forward the pointer
+ * to the remaining arguments.
+ *
+ * Returns: the number of the matched option  if a match is found against
+ * one of the custom options passed; 0 if no custom option matched and still
+ * some args need to be processed or autocompletion has been performed;
+ * -1 otherwise (no more args).
+ */
 int
-next_arg (NmCli *nmc, int *argc, char ***argv)
+next_arg (NmCli *nmc, int *argc, char ***argv, ...)
 {
-	int arg_num = *argc;
+	va_list args;
+	const char *cmd_option;
+
+	g_assert (*argc >= 0);
 
 	do {
-		if (arg_num > 0) {
+		int cmd_option_pos = 1;
+
+		if (*argc > 0) {
 			(*argc)--;
 			(*argv)++;
 		}
-		if (nmc && nmc->complete && *argc == 1 && ***argv == '-')
-			nmc_complete_strings (**argv, "--ask", "--show-secrets", NULL);
-		if (arg_num <= 1)
+		if (*argc == 0)
 			return -1;
+
+
+		va_start (args, argv);
+
+		if (nmc && nmc->complete && *argc == 1) {
+			while ((cmd_option = va_arg (args, const char *)))
+				nmc_complete_strings (**argv, cmd_option, NULL);
+
+			if (***argv == '-')
+				nmc_complete_strings (**argv, "--ask", "--show-secrets", NULL);
+
+			va_end (args);
+			return 0;
+		}
+
+		/* Check command dependent options first */
+		while ((cmd_option = va_arg (args, const char *))) {
+			/* strip heading "--" form cmd_option */
+			if (nmc_arg_is_option (**argv, cmd_option + 2)) {
+				va_end (args);
+				return cmd_option_pos;
+			}
+			cmd_option_pos++;
+		}
+
+		va_end (args);
+
 	} while (nmc && parse_global_arg (nmc, **argv));
 
 	return 0;
@@ -170,7 +215,7 @@ nmc_parse_args (nmc_arg_t *arg_arr, gboolean last, int *argc, char ***argv, GErr
 			return FALSE;
 		}
 
-		next_arg (NULL, argc, argv);
+		next_arg (NULL, argc, argv, NULL);
 	}
 
 	return TRUE;