macosx: fix resume playback guards, do not resume for folder urls

Folder URLs are likely DVD or bluray folders, which cannot be resumed
properly. Also fixes memleak, and unify guards. Do not save position
for input items which we do not resume afterwards anyway.

modules/gui/macosx/playlist.m

@@ -1476,6 +1476,30 @@
     [o_arrayToSave release];
 }
 
+- (BOOL)isValidResumeItem:(input_item_t *)p_item
+{
+    char *psz_url = input_item_GetURI(p_item);
+    NSString *o_url_string = toNSStr(psz_url);
+    free(psz_url);
+
+    if ([o_url_string isEqualToString:@""])
+        return NO;
+
+    NSURL *o_url = [NSURL URLWithString:o_url_string];
+
+    if (![o_url isFileURL])
+        return NO;
+
+    BOOL isDir = false;
+    if (![[NSFileManager defaultManager] fileExistsAtPath:[o_url path] isDirectory:&isDir])
+        return NO;
+
+    if (isDir)
+        return NO;
+
+    return YES;
+}
+
 - (void)continuePlaybackWhereYouLeftOff:(input_thread_t *)p_input_thread
 {
     NSDictionary *recentlyPlayedFiles = [[NSUserDefaults standardUserDefaults] objectForKey:@"recentlyPlayedMedia"];
@@ -1491,17 +1515,16 @@
             return;
         }
 
+        /* check for file existance before resuming */
+        if (![self isValidResumeItem:p_item])
+            return;
+
         char *psz_url = decode_URI(input_item_GetURI(p_item));
         if (!psz_url)
             return;
-
-        NSString *url = [NSString stringWithUTF8String:psz_url ? psz_url : ""];
+        NSString *url = toNSStr(psz_url);
         free(psz_url);
 
-        /* check for file existance before resuming */
-        if (![[NSFileManager defaultManager] fileExistsAtPath:[[NSURL URLWithString:[NSString stringWithUTF8String:input_item_GetURI(p_item)]] path]])
-            return;
-
         NSNumber *lastPosition = [recentlyPlayedFiles objectForKey:url];
         if (lastPosition && lastPosition.intValue > 0) {
             vlc_value_t pos;
@@ -1543,15 +1566,14 @@
     if (!p_item)
         return;
 
-    char *psz_url = decode_URI(input_item_GetURI(p_item));
-    NSString *url = [NSString stringWithUTF8String:psz_url ? psz_url : ""];
-    free(psz_url);
-
-    if (url.length < 1)
+    if (![self isValidResumeItem:p_item])
         return;
 
-    if ([url rangeOfString:@"file://" options:NSCaseInsensitiveSearch].location != 0)
+    char *psz_url = decode_URI(input_item_GetURI(p_item));
+    if (!psz_url)
         return;
+    NSString *url = toNSStr(psz_url);
+    free(psz_url);
 
     NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
     NSMutableDictionary *mutDict = [[NSMutableDictionary alloc] initWithDictionary:[defaults objectForKey:@"recentlyPlayedMedia"]];