fix(Multiple Values): fixes bug where number_of_values wasnt respected

i.e. assume, option -O set to multiple, and number_of_values(1)
set. And assume a *required* positional argument is also set.

-O some -O other pos

Would fail with pos arg not supplied.

Relates to #415

src/app/parser.rs

@@ -986,7 +986,7 @@ impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
         // Increment or create the group "args"
         self.groups_for_arg(opt.name).and_then(|vec| Some(matcher.inc_occurrences_of(&*vec)));
 
-        if val.is_none() || opt.is_set(ArgSettings::Multiple) {
+        if val.is_none() || (opt.is_set(ArgSettings::Multiple) && matcher.needs_more_vals(opt)) {
             return Ok(Some(opt.name));
         }
         Ok(None)
@@ -1054,31 +1054,7 @@ impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
                 return Err(Error::value_validation(e));
             }
         }
-        let vals = matcher.get(&*arg.name())
-                          .expect(INTERNAL_ERROR_MSG)
-                          .vals.len();
-        if let Some(max) = arg.max_vals() {
-            if (vals as u64) < max {
-                return Ok(Some(arg.name()));
-            } else {
-                return Ok(None);
-            }
-        }
-        if let Some(..) = arg.min_vals() {
-            return Ok(Some(arg.name()));
-        }
-        if let Some(num) = arg.num_vals() {
-            if arg.is_set(ArgSettings::Multiple) {
-                if (vals as u64) < num {
-                    return Ok(Some(arg.name()));
-                }
-            } else {
-                if (vals as u64 % num) != 0 {
-                    return Ok(Some(arg.name()));
-                }
-            }
-        }
-        if arg.is_set(ArgSettings::Multiple) {
+        if matcher.needs_more_vals(arg) {
             return Ok(Some(arg.name()));
         }
         Ok(None)

src/args/arg_matcher.rs

@@ -5,6 +5,8 @@ use std::ops::Deref;
 use vec_map::VecMap;
 
 use args::{ArgMatches, MatchedArg, SubCommand};
+use args::settings::ArgSettings;
+use args::AnyArg;
 
 #[doc(hidden)]
 pub struct ArgMatcher<'a>(pub ArgMatches<'a>);
@@ -91,6 +93,25 @@ impl<'a> ArgMatcher<'a> {
         let len = ma.vals.len() + 1;
         ma.vals.insert(len, val.to_owned());
     }
+
+    pub fn needs_more_vals<'b, A>(&self, o: &A) -> bool
+        where A: AnyArg<'a, 'b> {
+        if let Some(ma) = self.get(o.name()) {
+            if let Some(num) = o.num_vals() {
+                return if o.is_set(ArgSettings::Multiple) {
+                    ((ma.vals.len() as u64) % num) != 0
+                } else {
+                    num != (ma.vals.len() as u64)
+                };
+            } else if let Some(num) = o.max_vals() {
+                return !((ma.vals.len() as u64) > num);
+            } else if let Some(num) = o.min_vals() {
+                return (ma.vals.len() as u64) < num;
+            }
+            return o.is_set(ArgSettings::Multiple);
+        }
+        true
+    }
 }
 
 impl<'a> Into<ArgMatches<'a>> for ArgMatcher<'a> {