From 86671cf6dc492d748ccdc78374bd826e03b64796 Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Mon, 13 Oct 2008 13:45:55 +0000
Subject: [PATCH] PR 9814

svn: r12001
---
 collects/framework/private/text.ss | 34 +++++++++++++-----------------
 collects/tests/framework/text.ss   | 18 ++++++++++++++++
 2 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/collects/framework/private/text.ss b/collects/framework/private/text.ss
index ff0a337888..576ca6e182 100644
--- a/collects/framework/private/text.ss
+++ b/collects/framework/private/text.ss
@@ -359,6 +359,13 @@ WARNING: printf is rebound in the body of the unit to always
         (set! todo void))
       (inner (void) after-edit-sequence))
     
+    (define/augment (after-load-file success?)
+      (inner (void) after-load-file success?)
+      (set! ranges (make-hash))
+      (set! ranges-low 0) 
+      (set! ranges-high 0)
+      (set! ranges-list #f))
+    
     (define/public (highlight-range start end color [caret-space? #f] [priority 'low] [style 'rectangle])
       (unless (let ([exact-pos-int?
                      (λ (x) (and (integer? x) (exact? x) (x . >= . 0)))])
@@ -426,25 +433,14 @@ WARNING: printf is rebound in the body of the unit to always
         (let ([new-todo
                (λ ()
                  (let ([old-val (hash-ref ranges candidate #f)])
-                   (unless old-val
-                     (error 'unhighlight-range 
-                            "range not found; start: ~e end: ~e color: ~a caret-space?: ~e style: ~e"
-                            start end 
-                            (if (string? color)
-                                (format "~s" color)
-                                (format "(red: ~a green: ~a blue: ~a)"
-                                        (send color red)
-                                        (send color green)
-                                        (send color blue)))
-                            caret-space? 
-                            style))
-                   (let ([new-val (cdr old-val)])
-                     (cond
-                       [(null? new-val)
-                        (hash-remove! ranges candidate)]
-                       [else
-                        (hash-set! ranges candidate new-val)]))
-                 (set! ranges-list #f)))])
+                   (when old-val ;; may have been cleared by an earlier call to unhighlight-range
+                     (let ([new-val (cdr old-val)])
+                       (cond
+                         [(null? new-val)
+                          (hash-remove! ranges candidate)]
+                         [else
+                          (hash-set! ranges candidate new-val)]))
+                     (set! ranges-list #f))))])
           (cond
             [delayed-highlights?
              (set! todo
diff --git a/collects/tests/framework/text.ss b/collects/tests/framework/text.ss
index b276ac368f..00fe7cc228 100644
--- a/collects/tests/framework/text.ss
+++ b/collects/tests/framework/text.ss
@@ -143,3 +143,21 @@
        (send t unhighlight-range 1 2 "red")
        (send t unhighlight-range 1 2 "red")
        (length (send t get-highlighted-ranges))))))
+
+(let ([tmp-file (path->string (make-temporary-file "fwtesttmp~a"))])
+  (test
+   'highlight-range/revert
+   (lambda (x)
+     (delete-file tmp-file)
+     (equal? x 0))
+   (λ ()
+   (send-sexp-to-mred
+    `(let ([t (new text:basic%)])
+       (send t insert "abc")
+       (send t save-file ,tmp-file)
+       (send t highlight-range 0 3 "red")
+       (call-with-output-file ,tmp-file
+         (lambda (port) (display "x\n" port))
+         #:exists 'truncate)
+       (send t load-file)
+       (length (send t get-highlighted-ranges)))))))