show a dialog box saying that aspell/ispell cannot be

found instead of just silently not checking the spelling

also, fix a bug in that case that used to cause drracket
to just crash

Author: rfindler

collects/drracket/private/unit.rkt

@@ -42,7 +42,9 @@ module browser threading seems wrong.
          mred
          (prefix-in mred: mred)
 
-         mzlib/date)
+         mzlib/date
+         
+         framework/private/aspell)
 
 (provide unit@)
 
@@ -3641,10 +3643,16 @@ module browser threading seems wrong.
                 (send item check (and on? (send ed get-spell-check-strings))))]
              [callback
               (λ (item evt)
-                (define ed (get-edit-target-object))
-                (define old-val (send ed get-spell-check-strings))
-                (preferences:set 'framework:spell-check-on? (not old-val))
-                (send ed set-spell-check-strings (not old-val)))])
+                (define asp (find-aspell-binary-path))
+                (cond
+                 [asp
+                  (define ed (get-edit-target-object))
+                  (define old-val (send ed get-spell-check-strings))
+                  (preferences:set 'framework:spell-check-on? (not old-val))
+                  (send ed set-spell-check-strings (not old-val))]
+                 [else
+                  (message-box (string-constant drscheme)
+                               (string-constant cannot-find-ispell-or-aspell-path))]))])
         (new menu:can-restore-menu-item%
              [label (string-constant complete-word)]
              [shortcut #\/]

collects/framework/private/aspell.rkt

@@ -4,13 +4,27 @@
          racket/contract)
 
 (provide/contract
- [query-aspell (-> (and/c string? (not/c #rx"[\n]")) (listof (list/c number? number?)))])
+ [query-aspell (-> (and/c string? (not/c #rx"[\n]")) (listof (list/c number? number?)))]
+ [find-aspell-binary-path (-> (or/c path? #f))])
 
 (define aspell-candidate-paths
   '("/usr/bin" 
     "/usr/local/bin"
     "/bin"))
 
+(define (find-aspell-binary-path)
+  (define aspell (if (eq? (system-type) 'windows) "aspell.exe" "aspell"))
+  (define ispell (if (eq? (system-type) 'windows) "ispell.exe" "ispell"))
+  (or (find-executable-path aspell)
+      (find-executable-path ispell)
+      (for/or ([cp aspell-candidate-paths])
+        (define c1 (build-path cp aspell))
+        (define c2 (build-path cp ispell))
+        (or (and (file-exists? c1)
+                 c1)
+            (and (file-exists? c2)
+                 c2)))))
+
 (define aspell-req-chan (make-channel))
 (define aspell-thread #f)
 (define (start-aspell-thread)
@@ -24,17 +38,9 @@
              (define (fire-up-aspell)
                (unless already-attempted-aspell?
                  (set! already-attempted-aspell? #t)
-                 (define asp (or (find-executable-path "aspell")
-                                 (find-executable-path "ispell")
-                                 (for/or ([cp aspell-candidate-paths])
-                                   (define c1 (build-path cp "aspell"))
-                                   (define c2 (build-path cp "ispell"))
-                                   (or (and (file-exists? c1)
-                                            c1)
-                                       (and (file-exists? c2)
-                                            c2)))))
-                 (define aspell? (regexp-match? #rx"aspell" (path->string asp)))
+                 (define asp (find-aspell-binary-path))
                  (when asp
+                   (define aspell? (regexp-match? #rx"aspell" (path->string asp)))
                    (set! aspell-proc (apply process* asp "-a" (if aspell? '("--encoding=utf-8") '())))
                    (define line (read-line (list-ref aspell-proc 0)))
                    (log-info (format "framework: started speller: ~a" line))

collects/string-constants/private/english-string-constants.rkt

@@ -1686,4 +1686,5 @@ please adhere to these guidelines:
   ;; (technically, editors that implement color:text<%>)
   (spell-check-string-constants "Spell Check String Constants")
   (misspelled-text-color "Misspelled Text Color") ;; in the preferences dialog  
+  (cannot-find-ispell-or-aspell-path "Cannot find the aspell or ispell binary")
   )