matlab-scan.el:

(matlab--valid-arguments-keyword-point):
If previous code is 'end', make sure it matches a valid arguments block.
(matlab-re-search-keyword-forward,matlab-re-search-keyword-backward):
When checking if in string/comment, don't pass in 'all comments' as t.
Do that only if in a comment.

matlab-syntax.el:
(matlab-beginning-of-string-or-comment):
Make doc accurate.
(matlab-end-of-string-or-comment):
Fix logic for case when not in a comment to only skip all comments if
looking at a comment.  Avoid moving pt if just looking at whitespace.

matlab.el:
(matlab-do-functions-have-end-p):
Improve scanning for end to not do condition-case.
This was hiding an error that was causing incorrect answer.

matlab-scan.el

@@ -1019,8 +1019,13 @@ Assume basic keyword checks have already been done."
 	    (or (string= (nth 1 parent) "function")
 		;; If not a function, it might be an and, but that end will need to be
 		;; reverse tracked to see if it belongs to valid argument block.
-		(string= (nth 1 parent) "end")
-		;; TODO: be more rigid in this detection.
+		(and (string= (nth 1 parent) "end")
+		     (save-excursion
+		       (goto-char (nth 2 parent))
+		       (matlab--scan-block-backward)
+		       (let ((prevblock (matlab--mk-keyword-node)))
+		     	 (string= (nth 1 prevblock) "arguments")))
+		     )
 		))
        ))))
 
@@ -1200,7 +1205,10 @@ then skip and keep searching."
 	;; Check for simple cases that are invalid for keywords
 	;; for strings, comments, and lists, skip to the end of them
 	;; to not waste time searching for keywords inside.
-	(cond ((matlab-end-of-string-or-comment t)
+	(cond ((matlab-end-of-string-or-comment)
+	       ;; Test is only IF in a comment.  Also skip other comments
+	       ;; once we know we were in a comment.
+	       (matlab-end-of-string-or-comment t)
 	       (setq ans nil))
 	      ((matlab-in-list-p)
 	       (condition-case nil
@@ -1228,7 +1236,8 @@ then skip and keep searching."
 	;; Check for simple cases that are invalid for keywords
 	;; for strings, comments, and lists, skip to the end of them
 	;; to not waste time searching for keywords inside.
-	(cond ((matlab-beginning-of-string-or-comment t)
+	(cond ((matlab-beginning-of-string-or-comment)
+	       (matlab-beginning-of-string-or-comment t)
 	       (setq ans nil))
 	      ((matlab-beginning-of-outer-list)
 	       (setq ans nil))

matlab-syntax.el

@@ -446,11 +446,12 @@ bounds of the string or comment the cursor is in"
 
 (defsubst matlab-beginning-of-string-or-comment (&optional all-comments)
   "If the cursor is in a string or comment, move to the beginning.
-Returns non-nil if the cursor moved."
+Returns non-nil if the cursor is in a comment."
   (let* ((pps (syntax-ppss (point))))
     (prog1
 	(when (nth 8 pps)
 	  (goto-char (nth 8 pps))
+	  
 	  t)
       (when all-comments (forward-comment -100000)))))
 
@@ -476,9 +477,9 @@ Returns non-nil if the cursor moved."
 	    (error "Error navitaging syntax."))
 	  t)
       ;; else not in comment, but still skip 'all-comments' if requested.
-      (not (eq (point)
-	       (progn (when all-comments (forward-comment 100000))
-		      (point))))
+      (when (and all-comments (looking-at "\\s-*\\s<"))
+	(forward-comment 100000)
+	t)
       )))
 
 ;;; Navigating Lists

matlab.el

@@ -287,12 +287,16 @@ If the value is t, then return that."
 		 (goto-char (point-min))
 		 (matlab-find-code-line)
 		 (let ((matlab-functions-have-end t)) ;; pretend we have ends
-		   (beginning-of-line)
-		   (condition-case nil
-		       ;; Try to navigate.  If success, then t
-		       (progn (matlab-forward-sexp) t)
-		     ;; On failure, then no ends.
-		     (error nil))
+		   (back-to-indentation)
+		   (if (eq (matlab-on-keyword-p) 'decl)
+		       ;; If block scaning returns state, then that means
+		       ;; there is a missing end, so value is nil.
+		       ;; If it returns empty, then there is a matching end.
+		       (if (matlab--scan-block-forward)
+			   nil
+			 t)
+		     ;; Not on a decl, therefore just say nil, since block scanning would fail.
+		     nil)
 		   ))))
 	)
     ;; Else, just return the default.