=== modified file 'ChangeLog'
--- ChangeLog	2011-01-14 23:53:37 +0000
+++ ChangeLog	2011-01-15 00:03:32 +0000
@@ -1,5 +1,13 @@
 2011-01-15  Szymon Janc  <address@hidden>
 
+	* grub-core/io/gzio.c (test_header): For not seekable files: don't
+	check footer and set size to unknown.
+	(inflate_window): Set real size for unknown size file when it is
+	known.
+	(grub_gzio_read): Handle NULL buffer pointer.
+
+2011-01-15  Szymon Janc  <address@hidden>
+
 	* grub-core/kern/file.c (grub_file_read): Handle unknown file size.
 	(grub_file_seek): Likewise.
 

=== modified file 'grub-core/io/gzio.c'
--- grub-core/io/gzio.c	2010-12-26 20:15:31 +0000
+++ grub-core/io/gzio.c	2011-01-15 00:03:32 +0000
@@ -212,7 +212,7 @@ test_header (grub_file_t file)
 
   gzio->data_offset = grub_file_tell (gzio->file);
 
-  /* FIXME: don't do this on not easily seekable files.  */
+  if(grub_file_seekable(gzio->file))
   {
     grub_file_seek (gzio->file, grub_file_size (gzio->file) - 4);
     if (grub_file_read (gzio->file, &orig_len, 4) != 4)
@@ -224,6 +224,8 @@ test_header (grub_file_t file)
        But how can we know the real original size?  */
     file->size = grub_le_to_cpu32 (orig_len);
   }
+  else
+    file->size = GRUB_FILE_SIZE_UNKNOWN;
 
   initialize_tables (file);
 
@@ -1034,7 +1036,11 @@ inflate_window (grub_file_t file)
       if (! gzio->block_len)
 	{
 	  if (gzio->last_block)
-	    break;
+	    {
+	      if (file->size == GRUB_FILE_SIZE_UNKNOWN)
+		file->size = file->offset + gzio->wp;
+	      break;
+	    }
 
 	  get_new_block (file);
 	}
@@ -1186,9 +1192,11 @@ grub_gzio_read (grub_file_t file, char *
       if (size > len)
 	size = len;
 
-      grub_memmove (buf, srcaddr, size);
-
-      buf += size;
+      if (buf)
+	{
+	  grub_memmove (buf, srcaddr, size);
+	  buf += size;
+	}
       len -= size;
       ret += size;
       offset += size;