Summary
utf8: Errors in xstring-copy! and utf8-case-map
Metadata
- Id: 1436c42d1c592c10db05f262e1b44aad24b44666
- Trac id: 831
- Type: defect
- Reporter: sjamaan
- Owner: ashinn
- Cc:
- Status: closed
- Component: extensions
- Estimated difficulty:
- Resolution: fixed
- Priority: minor
- Milestone:
- Version: 4.7.x
- Changetime: 2012-07-20 16:40:00 UTC
- Created: 2012-05-13 13:02:50 UTC
- Keywords:
Description
utf8-srfi-13 has a problem where it's missing a set of parentheses; it's passing the procedure - as one of the arguments to +, causing an infinite loop in string-xcopy!:
#;1> (use utf8-srfi-13) #;2> (define s1 "foo") #;3> (define s2 (make-string 3)) #;4> (string-xcopy! s2 0 s1 1) ;; never stops, should put "oof" in s2
This is simple to fix:
Index: utf8-srfi-13.scm
===================================================================
--- utf8-srfi-13.scm (revision 26685)
+++ utf8-srfi-13.scm (working copy)
@@ -570,7 +570,7 @@
(define (string-xcopy target tstart s from . opt)
(let-optionals* opt ((to1 #f) (start 0) (end (utf8-string-length s)))
- (let ((to (or to1 (+ from - end start))))
+ (let ((to (or to1 (+ from (- end start)))))
(string-append (utf8-substring target 0 tstart)
(xsubstring s from to start end)
(utf8-substring target
There's another bug in utf8-case-map, which I don't know how to trigger (might be worthwhile trying to figure that out to add it as a regression test). There's two places where u32vector-ref is called with only one argument. This is also simple to fix, but as I wasn't able to trigger the bug I'm not sure this is correct:
Index: utf8-case-map.scm
===================================================================
--- utf8-case-map.scm (revision 26685)
+++ utf8-case-map.scm (working copy)
@@ -122,9 +122,9 @@
(>= hi lo)
(cond
((= i (u32vector-ref tab (* lo 4)))
- (u32vector-ref (+ (* lo 4) off)))
+ (u32vector-ref tab (+ (* lo 4) off)))
((= i (u32vector-ref tab (* hi 4)))
- (u32vector-ref (+ (* hi 4) off)))
+ (u32vector-ref tab (+ (* hi 4) off)))
(else
(let loop ((a lo) (b hi))
(if (= a b)
These bugs were found by the scrutinizer, see http://parenteses.org/mario/misc/specialize-report/install/utf8.html