* child_info.h (child_info_fork::handle_failure): Declare new function.

(child_info_fork::retry): New field.
* dcrt0.cc (__api_fatal_exit_val): Define.
(child_info_fork::handle_failure): Define new function.
(__api_fatal): Exit using __api_fatal_exit_val value.
* environ.cc (set_fork_retry): Set fork_retry based on CYGWIN environment
variable.
(parse_thing): Add "fork_retry" setting.
* fork.cc (fork_retry): Define.
(frok::parent): Reorganize to allow retry of failed child creation if child
signalled that it was ok to do so.
* heap.cc (heap_init): Signal parent via handle_failure when VirtualAlloc
fails.
* pinfo.h (EXITCODE_RETRY): Declare.
* sigproc.cc (child_info::sync): Properly exit with failure condition if called
for fork and didn't see subproc_ready.
* spawn.cc (spawn_guts): Use windows pid as first argument.
* winsup.h: Remove obsolete NEW_MACRO_VARARGS define.
(__api_fatal_exit_val): Declare.
(set_api_fatal_return): Define.
(in_dllentry): Declare.
* exceptions.cc (inside_kernel): Remove unneeded in_dllentry declaration.

winsup/cygwin/heap.cc

@@ -21,6 +21,7 @@ details. */
 #include "cygheap.h"
 #include "registry.h"
 #include "cygwin_version.h"
+#include "child_info.h"
 
 #define assert(x)
 
@@ -75,7 +76,7 @@ heap_init ()
 	  if ((reserve_size -= page_const) < allocsize)
 	    break;
 	}
-      if (!p)
+      if (!p && in_forkee && !fork_info->handle_failure (GetLastError ()))
 	api_fatal ("couldn't allocate heap, %E, base %p, top %p, "
 		   "reserve_size %d, allocsize %d, page_const %d",
 		   cygheap->user_heap.base, cygheap->user_heap.top,