From: Chris Hanson <org/chris-hanson/cph>
Date: Wed, 2 Jun 2010 08:36:42 +0000 (-0700)
Subject: Change %CANONICALIZE-SCALAR-VALUE-LIST to eliminate empty ranges.
X-Git-Tag: 20100708-Gtk~28
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=9d541885eb118e18cd72f5572345dc2367b4bd5b;p=mit-scheme.git

Change %CANONICALIZE-SCALAR-VALUE-LIST to eliminate empty ranges.
---

diff --git a/src/runtime/chrset.scm b/src/runtime/chrset.scm
index ec7f0b086..2c39a7fa3 100644
--- a/src/runtime/chrset.scm
+++ b/src/runtime/chrset.scm
@@ -204,9 +204,14 @@ USA.
     high))
 
 (define (%canonicalize-scalar-value-list ranges)
-  ;; Sort ranges in order, then merge adjacent ranges.
+  ;; Sort ranges in order, delete empty ranges, then merge adjacent
+  ;; ranges.
   (if (pair? ranges)
-      (let ((ranges (sort ranges %range<?)))
+      (let ((ranges
+	     (filter! (lambda (range)
+			(fix:< (%range-start range)
+			       (%range-end range)))
+		      (sort ranges %range<?))))
 	(let loop
 	    ((start1 (%range-start (car ranges)))
 	     (end1 (%range-end (car ranges)))