Limit circle border width.

1 files changed, 5 insertions, 3 deletions

diff --git a/pict.scm b/pict.scm
index 5a5b9b1..36f61c9 100644
--- a/pict.scm
+++ b/pict.scm
@@ -531,7 +531,9 @@ strings that are built from the list of attributes LST."
                  #:key
                  (border-color "black")
                  (border-width 1))
-  (let ((radius (- (/ size 2) border-width)))
+  (let* ((border-width (min border-width (/ size 2)))
+         (radius (exact->inexact
+                  (/ (- size border-width) 2))))
     (make-pict
      `(svg (@ (width ,size)
               (height ,size)
@@ -542,8 +544,8 @@ strings that are built from the list of attributes LST."
                                  ("stroke" ,border-color)
                                  ("stroke-width"
                                   ,(number->string border-width)))))
-                      (cx ,(+ radius border-width))
-                      (cy ,(+ radius border-width))
+                      (cx ,(+ radius (/ border-width 2)))
+                      (cy ,(+ radius (/ border-width 2)))
                       (r  ,radius)))))))
 
 (define* (disk size