* Makefile.in (DLL_OFILES): Add hookapi.o. Eliminate some cruft.

* cygheap.h (cygheap_types): Add new enum: HEAP_1_HOOK.
(hook_chain): New struct.
(init_cygheap::hooks): Define new element.
* cygheap.cc (cygheap_fixup_in_child): Zero hook chain on exec.
* dcrt0.cc (dll_crt0_1): Call ld_preload just before calling main function.
* external.cc (cygwin_internal): Implement CW_HOOK.
* fork.cc (fork_child): Call fixup_hooks_after_fork.
* init.cc (cygwin_hmodule): Reinstate after a long absence.
* include/sys/cygwin.h: Define CW_HOOK.
* hookapi.cc: New file.
* select.cc (start_thread_socket): Add debugging output.
* fhandler_disk_file.cc (fhandler_disk_file::fchmod): gcc 4.x accommodation.
* fhandler_socket.cc (fhandler_socket::connect): Make sure that err is
initialized.

winsup/cygwin/dcrt0.cc

@@ -41,6 +41,8 @@ details. */
 
 #define PREMAIN_LEN (sizeof (user_data->premain) / sizeof (user_data->premain[0]))
 
+void ld_preload ();
+
 HANDLE NO_COPY hMainProc = (HANDLE) -1;
 HANDLE NO_COPY hMainThread;
 
@@ -857,6 +859,7 @@ dll_crt0_1 (char *)
      do this for noncygwin case since the signal thread is blocked due to
      LoadLibrary serialization. */
   wait_for_sigthread ();
+  ld_preload ();
   if (user_data->main)
     exit (user_data->main (__argc, __argv, *user_data->envptr));
 }