New flag to prevent error in candidates fns.

* helm.el (helm--ignore-errors): New.
(helm-internal): Reset it.
(helm-get-candidates):                            Use it.
* helm-files.el (helm-find-files-get-candidates): Use it.

helm-files.el

@@ -1761,6 +1761,9 @@ purpose."
          invalid-basedir
          non-essential
          (tramp-verbose helm-tramp-verbose)) ; No tramp message when 0.
+    ;; Tramp check if path is valid without waiting a valid
+    ;; connection and may send a file-error.
+    (setq helm--ignore-errors (file-remote-p path))
     (set-text-properties 0 (length path) nil path)
     ;; Issue #118 allow creation of newdir+newfile.
     (unless (or

helm.el

@@ -1001,6 +1001,10 @@ because they are automatically added.
 You should not modify this yourself unless you know what you are doing.")
 ;; Same as `ffap-url-regexp' but keep it here to ensure `ffap-url-regexp' is not nil.
 (defvar helm--url-regexp "\\(news\\(post\\)?:\\|mailto:\\|file:\\|\\(ftp\\|https?\\|telnet\\|gopher\\|www\\|wais\\)://\\)")
+(defvar helm--ignore-errors nil
+  "Flag to prevent helm popping up errors in candidates functions.
+Should be set in candidates functions if needed, will be restored
+at end of session.")
 
 ;; Utility: logging
 (defun helm-log (format-string &rest args)
@@ -1941,6 +1945,7 @@ ANY-KEYMAP ANY-DEFAULT ANY-HISTORY See `helm'."
       ;; Reset helm-pattern so that lambda's using it
       ;; before running helm will not start with its old value.
       (setq helm-pattern "")
+      (setq helm--ignore-errors nil)
       (and old--cua (cua-mode 1))
       (helm-log-save-maybe))))
 
@@ -2752,7 +2757,8 @@ Helm plug-ins are realized by this function."
            ;; Candidates will be filtered later in process filter.
            candidates)
           ;; An error occured in candidates function.
-          (cfn-error (funcall notify-error cfn-error))
+          (cfn-error (unless helm--ignore-errors
+                       (funcall notify-error cfn-error)))
           ;; Candidates function returns no candidates.
           ((or (null candidates)
                ;; Can happen when the output of a process