bk commit into 5.0 tree (Kristofer.Pettersson:1.2273) BUG#23010

[kpettersson]

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ChangeSet@stripped, 2006-10-09 21:13:37+02:00, Kristofer.Pettersson@naruto. +2 -0
  Bug#23010 _my_b_read() passing illegal file handles to my_seek()
  - The io cache flag seek_not_done was not set properly in the reinit_
  io_chache function call and this led my_seek to be called despite an
  invalid file handle.
  - Added a test in reinit_io_cache to ensure we have a valid file handle
  before setting seek_not_done flag.

  mysys/mf_iocache.c@stripped, 2006-10-09 20:46:24+02:00, Kristofer.Pettersson@naruto. +5 -1
    Added a test to only trigger my_seek function calls if we have 
    a valid file descriptor.

  mysys/my_seek.c@stripped, 2006-10-09 20:46:25+02:00, Kristofer.Pettersson@naruto. +7 -2
    Refactored incomplete condition into an assertion. This also ensures that
    newpos is initialized.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	Kristofer.Pettersson
# Host:	naruto.
# Root:	C:/cpp/bug23010/my50-bug23010

--- 1.55/mysys/mf_iocache.c	2006-10-09 21:13:55 +02:00
+++ 1.56/mysys/mf_iocache.c	2006-10-09 21:13:55 +02:00
@@ -333,7 +333,11 @@
     {
       info->read_end=info->write_pos;
       info->end_of_file=my_b_tell(info);
-      info->seek_not_done=1;
+      /*
+        Trigger a new seek only if we have a valid
+        file handle.
+      */
+      info->seek_not_done= (info->file != -1);
     }
     else if (type == WRITE_CACHE)
     {

--- 1.12/mysys/my_seek.c	2006-10-09 21:13:55 +02:00
+++ 1.13/mysys/my_seek.c	2006-10-09 21:13:55 +02:00
@@ -29,8 +29,13 @@
 		   whence, MyFlags));
   DBUG_ASSERT(pos != MY_FILEPOS_ERROR);		/* safety check */
 
-  if (-1 != fd)
-    newpos=lseek(fd, pos, whence);
+  /*
+      Make sure we are using a valid file descriptor!
+  */
+  DBUG_ASSERT(fd != -1);
+
+  newpos= lseek(fd, pos, whence);
+  
   if (newpos == (os_off_t) -1)
   {
     my_errno=errno;