Patch: Initialise new file space to zero for Beos

[Nick Clifton <nickc at cygnus dot com>]

Hi Guys,

  Does anyone have any objections to my applying the following patch ?

  It enhances bfd_seek() so that, for BeOS only, any newly created
  file space is initialised to zero.  The BeOS fseek function does not
  do this automatically (unlike fseek on other OSes), and as a result
  binary comparisons of identical files fail.  This means that
  bootstrapping under BeOS does not work.

Cheers
	Nick


1999-09-18  Nick Clifton  <nickc@cygnus.com>

	* libbfd.c (bfd_seek): For BeOS, write zeros into extended
	file space.  Patch developed with Fred Fish.

Index: libbfd.c
===================================================================
RCS file: /cvs/binutils/binutils/bfd/libbfd.c,v
retrieving revision 1.6
diff -p -r1.6 libbfd.c
*** libbfd.c	1999/09/12 14:27:21	1.6
--- libbfd.c	1999/09/18 09:38:57
*************** bfd_seek (abfd, position, direction)
*** 723,728 ****
--- 723,774 ----
    if (direction == SEEK_SET && abfd->my_archive != NULL)
      file_position += abfd->origin;
  
+ #if defined __BEOS__
+   {
+     file_ptr eof;
+     file_ptr pos;
+ 
+     pos = ftell (f);
+     fseek (f, 0L, SEEK_END);
+     eof = ftell (f);
+ 
+     if (direction == SEEK_CUR)
+       {
+ 	direction = SEEK_SET;
+ 	file_position += pos;
+       }
+   
+     /* When extending a file beyond its original length the fseek() function
+        under BeOS does not initialise the new space to zero.  This means that
+        random garbage can be picked up, which in turn means that two identical
+        files assembled and linked in the same way can nevertheless still fail
+        a binary compare.  We fix this here by explicitly initialising the
+        extra space.  */
+     if (eof < file_position)
+       {
+ 	file_ptr diff;
+ 	static char zeros[512];
+       
+ 	diff = file_position - eof;
+ 
+ 	while (diff >= sizeof (zeros))
+ 	  {
+ 	    fwrite (zeros, sizeof (zeros), 1, f);
+ 	    diff -= sizeof (zeros);
+ 	  }
+ 	
+ 	if (diff > 0)
+ 	  fwrite (zeros, diff, 1, f);
+ 	
+ 	/* In theory we do not need to perform the fseek now, since the fwrite
+ 	   calls will have moved the file pointer to the correct location.  In
+ 	   practice however we leave the call in, just in case something went
+ 	   wrong with the fwrites and we missed it.  (After all we are not
+ 	   checking their return codes).  */
+       }
+   }
+ #endif
+   
    result = fseek (f, file_position, direction);
  
    if (result != 0)