Index: ossp-pkg/sio/al.c
RCS File: /v/ossp/cvs/ossp-pkg/sio/Attic/al.c,v
rcsdiff -q -kk '-r1.32' '-r1.33' -u '/v/ossp/cvs/ossp-pkg/sio/Attic/al.c,v' 2>/dev/null
--- al.c	2002/10/25 13:29:02	1.32
+++ al.c	2002/11/04 13:14:50	1.33
@@ -137,17 +137,29 @@
  * number of bytes a chunk can be grown to the beginning
  * we must not grow a chunk in a shared buffer since
  * we do not track other chunks sharing the buffer
+ *
+ * empty chunks can be aligned with end
  */
 #define AL_CHUNK_PRESERVE(alc,label) \
     ( (alc) != NULL \
      ? (  (alc)->buf->usecount > 1 || !AL_SAME_LABEL(alc,label) \
         ? 0 \
-        : (alc)->begin) \
+        : (alc)->end <= (alc)->begin ? \
+          (alc)->buf->size \
+          : (alc)->begin) \
      : 0)
 
-/* grow chunk to the beginning */
+/*
+ * grow chunk to the beginning
+ *
+ * empty chunks can be aligned with end
+ */
 #define AL_PRESIZE(al, alc, n) \
-    do { (alc)->begin -= n; (al)->bytes += (n); } while (0)
+    do { \
+        if ((alc)->end <= (alc)->begin) \
+            (alc)->end = (alc)->begin = (alc)->buf->size; \
+        (alc)->begin -= n; (al)->bytes += (n); \
+    } while (0)
 
 /*
  * callback to release buffer memory allocated by the library