From: Corinna Vinschen <cori...@vinschen.de>

Introducing an independent Cygwin PID introduced a regression:

The expectation is that the myself pinfo pointer always points to a
specific address right in front of the loaded Cygwin DLL.

However, commit b5e1003722cb14235c4f166be72c09acdffc62ea "Cygwin:
processes: use dedicated Cygwin PID rather than Windows PID" and commit
88605243a19bbc2b6b9be36b99f513140b972e38 "Cygwin: fix child getting
another pid after spawnve" broke this.  To get myself at the right
address requires to call init with h0 set to INVALID_HANDLE_VALUE or an
existing address:

void
pinfo::init (pid_t n, DWORD flag, HANDLE h0)
{
  [...]
  if (!h0 || myself.h)
    [...]
  else
    {
      shloc = SH_MYSELF;
      if (h0 == INVALID_HANDLE_VALUE)       <-- !!!
        h0 = NULL;
    }

That was not the case anymore after the above commits.  This patch makes
sure to set the handle to INVALID_HANDLE_VALUE again when creating a new
process, so init knows that myself has to be created in the right spot.

While at it, fix a potential uninitialized handle value in
child_info_spawn::handle_spawn.

Signed-off-by: Corinna Vinschen <cori...@vinschen.de>
---
 winsup/cygwin/dcrt0.cc | 2 +-
 winsup/cygwin/pinfo.cc | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
index fb726a739ccf..86ab7256484c 100644
--- a/winsup/cygwin/dcrt0.cc
+++ b/winsup/cygwin/dcrt0.cc
@@ -652,7 +652,7 @@ void
 child_info_spawn::handle_spawn ()
 {
   extern void fixup_lockf_after_exec (bool);
-  HANDLE h;
+  HANDLE h = INVALID_HANDLE_VALUE;
   if (!dynamically_loaded || get_parent_handle ())
       {
        cygheap_fixup_in_child (true);
diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc
index cdbd8bd7eaf3..b67d660ae04d 100644
--- a/winsup/cygwin/pinfo.cc
+++ b/winsup/cygwin/pinfo.cc
@@ -62,11 +62,10 @@ pinfo::thisproc (HANDLE h)
     {
       cygheap->pid = create_cygwin_pid ();
       flags |= PID_NEW;
+      h = INVALID_HANDLE_VALUE;
     }
   /* spawnve'd process got pid in parent, cygheap->pid has been set in
      child_info_spawn::handle_spawn. */
-  else if (h == INVALID_HANDLE_VALUE)
-    h = NULL;
 
   init (cygheap->pid, flags, h);
   procinfo->process_state |= PID_IN_USE;
-- 
2.20.1

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