Ticket #557: pp-fix.diff

extras.scm

@@ -337 +337 @@
                                     (let loop ((i 0) (j 0) (col (out "\"" col)))
                                       (if (and col (fx< j (string-length obj)))
                                           (let ((c (string-ref obj j)))
-                                            (cond ((assq c '((#\\ . "\\")
-                                                             (#\" . "\\\"")
-                                                             (#\tab . "\\t")
-                                                             (#\newline . "\\n")
-                                                             (#\return . "\\r")))
-                                                   =>
-                                                   (lambda (a)
-                                                     (let ((col2 
-                                                            (out (##sys#substring obj i j) col)))
-                                                       (loop (fx+ j 1)
-                                                             (fx+ j 1)
-                                                             (out (cdr a) col2)))))
-                                                  (else (loop i (fx+ j 1) col))))
+                                            (if (or (char=? c #\\)
+                                                    (char=? c #\"))
+                                                (loop j
+                                                      (+ j 1)
+                                                      (out "\\"
+                                                           (out (##sys#substring obj i j)
+                                                                col)))
+                                                (cond ((assq c '((#\tab . "\\t")
+                                                                 (#\newline . "\\n")
+                                                                 (#\return . "\\r")))
+                                                       =>
+                                                       (lambda (a)
+                                                         (let ((col2
+                                                                (out (##sys#substring obj i j) col)))
+                                                           (loop (fx+ j 1)
+                                                                 (fx+ j 1)
+                                                                 (out (cdr a) col2)))))
+                                                      (else (loop i (fx+ j 1) col)))))
                                           (out "\""
                                                (out (##sys#substring obj i j) col))))))
             ((char? obj)        (if display?