1 files changed, 92 insertions, 0 deletions
diff --git a/private/crt32/winheap/expand.c b/private/crt32/winheap/expand.c
new file mode 100644
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+++ b/private/crt32/winheap/expand.c
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+/***
+*expand.c - Win32 expand heap routine
+*
+*	Copyright (c) 1991-1992, Microsoft Corporation.  All rights reserved.
+*
+*Purpose:
+*
+*Revision History:
+*	01-15-92  JCR	Module created.
+*	02-04-92  GJF	Replaced windows.h with oscalls.h.
+*	05-06-92  DJM	ifndef out of POSIX build.
+*	09-23-92  SRW	Change winheap code to call NT directly always
+*	10-15-92  SKS	Removed the ill-named HEAP_GROWTH_ALLOWED flag
+*			which was causing a bug: _expand was behaving like
+*			realloc(), by moving the block when it could not be
+*			grown in place.  _expand() must NEVER move the block.
+*			Also added a safety check to work around a bug in
+*			HeapReAlloc, where it returns success even
+*			when it fails to grow the block in place.
+*	10-28-92  SRW	Change winheap code to call Heap????Ex calls
+*	11-05-92  SKS	Change name of variable "CrtHeap" to "_crtheap"
+*	11-07-92  SRW   _NTIDW340 replaced by linkopts\betacmp.c
+*	11-16-92  SRW   Heap???Ex functions renamed to Heap???
+*
+*******************************************************************************/
+
+#ifndef _POSIX_
+
+#include <cruntime.h>
+#include <malloc.h>
+#include <winheap.h>
+#include <oscalls.h>
+
+/***
+*void *_expand(void *pblck, size_t newsize) - expand/contract a block of memory
+*	in the heap
+*
+*Purpose:
+*	Resizes a block in the heap to newsize bytes. newsize may be either
+*	greater (expansion) or less (contraction) than the original size of
+*	the block. The block is NOT moved.
+*
+*	NOTES:
+*
+*	(1) In this implementation, if the block cannot be grown to the
+*	desired size, the resulting block will NOT be grown to the max
+*	possible size.	(That is, either it works or it doesn't.)
+*
+*	(2) Unlike other implementations, you can NOT pass a previously
+*	freed block to this routine and expect it to work.
+*
+*Entry:
+*	void *pblck	- pointer to block in the heap previously allocated
+*			  by a call to malloc(), realloc() or _expand().
+*
+*	size_t newsize	- requested size for the resized block
+*
+*Exit:
+*	Success:  Pointer to the resized memory block (i.e., pblck)
+*	Failure:  NULL
+*
+*Uses:
+*
+*Exceptions:
+*	If pblck does not point to a valid allocation block in the heap,
+*	_expand() will behave unpredictably and probably corrupt the heap.
+*
+*******************************************************************************/
+
+void * _CALLTYPE1 _expand(pblock, n)
+void * pblock;
+size_t	n;
+
+{
+  void * p;
+
+  p = HeapReAlloc(_crtheap,
+                  HEAP_REALLOC_IN_PLACE_ONLY,
+                  pblock,
+                  n ? n : 1
+                 );
+
+  /**
+   * Temporary BUG work-around:
+   *	HeapReAlloc sometimes (often?) returns success
+   *	even when there has been a failure to grow in place.
+   *	This conditional will recognize this case and handle it.
+  **/
+  return ( p == pblock ) && ( _msize(pblock) >= n ) ? pblock : NULL;
+}
+
+#endif  /* !_POSIX_ */