Merge pull request #122 from kyanagi/appropriate-error-messages-when-no-fake-cursors-exist

Show appropriate error messages on trying skipping/unmarking commands with no fake cursors

mc-mark-more.el

@@ -107,6 +107,8 @@ Use like case-fold-search, don't recommend setting it globally.")
         (match-point-getter (ecase direction
                               (forwards 'match-beginning)
                               (backwards 'match-end))))
+    (if (and skip-last (not furthest-cursor))
+        (error "No cursors to be skipped")
       (mc/save-excursion
        (goto-char start-char)
        (when skip-last
@@ -117,7 +119,7 @@ Use like case-fold-search, don't recommend setting it globally.")
              (when point-out-of-order
                (exchange-point-and-mark))
              (mc/create-fake-cursor-at-point))
-       (error "no more matches found.")))))
+         (error "no more matches found."))))))
 
 ;;;###autoload
 (defun mc/mark-next-like-this (arg)
@@ -127,7 +129,10 @@ With zero ARG, skip the last one and mark next."
   (interactive "p")
   (if (region-active-p)
       (if (< arg 0)
-          (mc/remove-fake-cursor (mc/furthest-cursor-after-point))
+          (let ((cursor (mc/furthest-cursor-after-point)))
+            (if cursor
+                (mc/remove-fake-cursor cursor)
+              (error "No cursors to be unmarked")))
         (mc/mark-more-like-this (= arg 0) 'forwards))
     (mc/mark-lines arg 'forwards))
   (mc/maybe-multiple-cursors-mode))
@@ -152,7 +157,10 @@ With zero ARG, skip the last one and mark next."
   (interactive "p")
   (if (region-active-p)
       (if (< arg 0)
-          (mc/remove-fake-cursor (mc/furthest-cursor-before-point))
+          (let ((cursor (mc/furthest-cursor-before-point)))
+            (if cursor
+                (mc/remove-fake-cursor cursor)
+              (error "No cursors to be unmarked")))
         (mc/mark-more-like-this (= arg 0) 'backwards))
     (mc/mark-lines arg 'backwards))
   (mc/maybe-multiple-cursors-mode))