[PATCH 2/4] GDB/MI: fix and simplify mi_valid_noargs utility function

[Cleber Rosa <crosa@redhat.com>]

This function was supposed to check if a command that takes no
arguments was called appropriately, that is, without any arguments.

Turns out that the implementation, relying on mi_getopt, would always
return -1, either because:

 * no argument was given, then the option index (*oind) would be equal
   to the argument count (argc)
 * the argument given did not start with a dash (arg[0] != '-')

If the command should take no arguments, then it should be OK to just
check the given argument count.

gdb/ChangeLog:
    2015-10-05  Cleber Rosa  <crosa@redhat.com>

    * mi/mi-getopt.c (mi_valid_noargs): Simplify/fix the function by
    looking at the argument count.
---
 gdb/mi/mi-getopt.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/gdb/mi/mi-getopt.c b/gdb/mi/mi-getopt.c
index 0a07a39..574ccd2 100644
--- a/gdb/mi/mi-getopt.c
+++ b/gdb/mi/mi-getopt.c
@@ -95,18 +95,14 @@ mi_getopt_allow_unknown (const char *prefix, int argc, char **argv,
   return mi_getopt_1 (prefix, argc, argv, opts, oind, oarg, 0);
 }
 
+/* Tests if a command that takes no arguments was properly used.
+   Returns 1 if no options were given, otherwise return 0.  */
+
 int 
 mi_valid_noargs (const char *prefix, int argc, char **argv) 
 {
-  int oind = 0;
-  char *oarg;
-  static const struct mi_opt opts[] =
-    {
-      { 0, 0, 0 }
-    };
-
-  if (mi_getopt (prefix, argc, argv, opts, &oind, &oarg) == -1)
-    return 1;
-  else
+  if (argc > 0)
     return 0;
+
+  return 1;
 }
-- 
2.4.3