X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Ffb-mem.c;h=64a1930e131141eec1542c6a9844982b01ab0604;hb=ff36b07f44efa12a78809ee05bd6d0c25fc60495;hp=0f3158c379dbc9e7ae666c35d90e0d91c6bdfb32;hpb=cf83e06e4158617e981fef5bf3878315b23bf7f9;p=libucw.git

diff --git a/lib/fb-mem.c b/lib/fb-mem.c
index 0f3158c3..64a1930e 100644
--- a/lib/fb-mem.c
+++ b/lib/fb-mem.c
@@ -1,5 +1,5 @@
 /*
- *	Sherlock Library -- Fast Buffered I/O on Memory Streams
+ *	UCW Library -- Fast Buffered I/O on Memory Streams
  *
  *	(c) 1997--2002 Martin Mares <mj@ucw.cz>
  *
@@ -110,7 +110,7 @@ fbmem_seek(struct fastbuf *f, sh_off_t pos, int whence)
   /* Yes, this is linear. But considering the average number of buckets, it doesn't matter. */
   for (b=m->first; b; b=b->next)
     {
-      if (pos <= b->pos + b->size) /* <=, because we need to be able to seek just after file end */
+      if (pos <= b->pos + (sh_off_t)b->size) /* <=, because we need to be able to seek just after file end */
 	{
 	  f->buffer = b->data;
 	  f->bptr = b->data + (pos - b->pos);
@@ -120,6 +120,14 @@ fbmem_seek(struct fastbuf *f, sh_off_t pos, int whence)
 	  return;
 	}
     }
+  if (!m->first && !pos)
+    {
+      /* Seeking to offset 0 in an empty file needs an exception */
+      f->buffer = f->bptr = f->bufend = NULL;
+      f->pos = 0;
+      FB_MEM(f)->block = NULL;
+      return;
+    }
   die("fbmem_seek to invalid offset");
 }
 
@@ -171,6 +179,7 @@ fbmem_clone_read(struct fastbuf *b)
   f->refill = fbmem_refill;
   f->seek = fbmem_seek;
   f->close = fbmem_close;
+  f->can_overwrite_buffer = 1;
   return f;
 }