* libio/fileops.c (_IO_file_seekoff_mmap): Don't rely on FP->_offset,

	which gets moved around.  Calculate size of mmap'd buffer instead.

1 files changed, 2 insertions, 1 deletions

diff --git a/libio/fileops.c b/libio/fileops.c
index 1794dce57f..5603e5a30a 100644
--- a/libio/fileops.c
+++ b/libio/fileops.c
@@ -932,7 +932,8 @@ _IO_file_seekoff_mmap (fp, offset, dir, mode)
      using a pushback buffer, but in the usual case has the same value as
      (fp->_IO_read_ptr - fp->_IO_buf_base).  */
   if (mode == 0)
-    return fp->_offset - (fp->_IO_read_end - fp->_IO_read_ptr);
+    return ((fp->_IO_buf_end - fp->_IO_buf_base)
+	    - (fp->_IO_read_end - fp->_IO_read_ptr));
 
   switch (dir)
     {