Cygwin: pty: Fix script command crash on console in Win7.

- Previously, the command "cmd /c script -c cmd" in console of Win7
  crashes. This seems to be due to a bug (?) of AttachConsole().
  This patch adds workaround for this issue.

  Currently, pty reattaches to the console of the process which is
  predetermined by ConsoleProcessList() after temporarily attaching
  to another console. After that, the console output handle opened
  with the name "CONOUT$" may not be accessible in Win7 or Vista.
  This seems to happen when the attached process does not have the
  same handle even if the console attached is the same. With this
  patch, cygwin-console-helper which is started when pty master is
  opened in console, is utilized to be a target process to which
  pty reattaches if the OS is Win7 or Vista.

6 files changed, 91 insertions, 4 deletions

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index 291aa5b..2ff99ae 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -1983,6 +1983,7 @@ class fhandler_termios: public fhandler_base
   virtual void cleanup_before_exit () {}
   virtual bool need_console_handler () { return false; }
   virtual bool need_send_ctrl_c_event () { return true; }
+  virtual DWORD get_helper_pid () { return 0; }
 };
 
 enum ansi_intensity
@@ -2466,6 +2467,7 @@ public:
     HANDLE from_slave_nat;
     HANDLE output_mutex;
     tty *ttyp;
+    DWORD helper_pid;
   };
 private:
   int pktmode;			// non-zero if pty in a packet mode.
@@ -2477,6 +2479,9 @@ private:
   HANDLE to_master, from_master;
   cygthread *master_fwd_thread;	// Master forwarding thread
   HANDLE thread_param_copied_event;
+  HANDLE helper_goodbye;
+  HANDLE helper_h_process;
+  DWORD helper_pid;
 
 public:
   HANDLE get_echo_handle () const { return echo_r; }
@@ -2531,6 +2536,7 @@ public:
   void get_master_fwd_thread_param (master_fwd_thread_param_t *p);
   void set_mask_flusho (bool m) { get_ttyp ()->mask_flusho = m; }
   bool need_send_ctrl_c_event ();
+  DWORD get_helper_pid () { return helper_pid; }
 };
 
 class fhandler_dev_null: public fhandler_base
diff --git a/winsup/cygwin/fhandler_termios.cc b/winsup/cygwin/fhandler_termios.cc
index 8dd3805..f4d7493 100644
--- a/winsup/cygwin/fhandler_termios.cc
+++ b/winsup/cygwin/fhandler_termios.cc
@@ -359,7 +359,9 @@ fhandler_termios::process_sigs (char c, tty* ttyp, fhandler_termios *fh)
 	  acquire_attach_mutex (mutex_timeout);
 	  pinfo pinfo_resume = pinfo (myself->ppid);
 	  DWORD resume_pid = 0;
-	  if (pinfo_resume)
+	  if (fh && fh->get_helper_pid ())
+	    resume_pid = fh->get_helper_pid ();
+	  else if (pinfo_resume)
 	    resume_pid = pinfo_resume->dwProcessId;
 	  else
 	    resume_pid = fhandler_pty_common::get_console_process_id
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 0cd69f3..399b6ef 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -534,7 +534,9 @@ fhandler_pty_master::accept_input ()
       acquire_attach_mutex (mutex_timeout);
       pinfo pinfo_resume = pinfo (myself->ppid);
       DWORD resume_pid;
-      if (pinfo_resume)
+      if (helper_pid)
+	resume_pid = helper_pid;
+      else if (pinfo_resume)
 	resume_pid = pinfo_resume->dwProcessId;
       else
 	resume_pid = get_console_process_id (myself->dwProcessId, false);
@@ -2170,6 +2172,16 @@ fhandler_pty_master::close ()
 	  get_ttyp ()->stop_fwd_thread = true;
 	  WriteFile (to_master_nat, "", 0, &len, NULL);
 	  master_fwd_thread->detach ();
+	  if (helper_goodbye)
+	    {
+	      SetEvent (helper_goodbye);
+	      WaitForSingleObject (helper_h_process, INFINITE);
+	      CloseHandle (helper_h_process);
+	      CloseHandle (helper_goodbye);
+	      helper_pid = 0;
+	      helper_h_process = 0;
+	      helper_goodbye = NULL;
+	    }
 	}
     }
 
@@ -2878,7 +2890,9 @@ fhandler_pty_master::pty_master_fwd_thread (const master_fwd_thread_param_t *p)
       acquire_attach_mutex (mutex_timeout);
       pinfo pinfo_resume = pinfo (myself->ppid);
       DWORD resume_pid;
-      if (pinfo_resume)
+      if (p->helper_pid)
+	resume_pid = p->helper_pid;
+      else if (pinfo_resume)
 	resume_pid = pinfo_resume->dwProcessId;
       else
 	resume_pid = get_console_process_id (myself->dwProcessId, false);
@@ -3071,6 +3085,57 @@ fhandler_pty_master::setup ()
       goto err;
     }
   WaitForSingleObject (thread_param_copied_event, INFINITE);
+
+  if (wincap.has_broken_attach_console ()
+      && _major (myself->ctty) == DEV_CONS_MAJOR
+      && !(!pinfo (myself->ppid) && getenv ("ConEmuPID")))
+    {
+      HANDLE hello = CreateEvent (&sec_none, true, false, NULL);
+      HANDLE goodbye = CreateEvent (&sec_none, true, false, NULL);
+      WCHAR cmd[MAX_PATH];
+      path_conv helper ("/bin/cygwin-console-helper.exe");
+      size_t len = helper.get_wide_win32_path_len ();
+      helper.get_wide_win32_path (cmd);
+      __small_swprintf (cmd + len, L" %p %p", hello, goodbye);
+
+      STARTUPINFOEXW si;
+      PROCESS_INFORMATION pi;
+      ZeroMemory (&si, sizeof (si));
+      si.StartupInfo.cb = sizeof (STARTUPINFOEXW);
+
+      SIZE_T bytesRequired;
+      InitializeProcThreadAttributeList (NULL, 1, 0, &bytesRequired);
+      si.lpAttributeList = (PPROC_THREAD_ATTRIBUTE_LIST)
+	HeapAlloc (GetProcessHeap (), 0, bytesRequired);
+      InitializeProcThreadAttributeList (si.lpAttributeList,
+					 1, 0, &bytesRequired);
+      HANDLE handles_to_inherit[] = {hello, goodbye};
+      UpdateProcThreadAttribute (si.lpAttributeList,
+				 0,
+				 PROC_THREAD_ATTRIBUTE_HANDLE_LIST,
+				 handles_to_inherit,
+				 sizeof (handles_to_inherit),
+				 NULL, NULL);
+      if (CreateProcessW (NULL, cmd, &sec_none, &sec_none,
+			  TRUE, EXTENDED_STARTUPINFO_PRESENT,
+			  NULL, NULL, &si.StartupInfo, &pi))
+	{
+	  WaitForSingleObject (hello, INFINITE);
+	  CloseHandle (hello);
+	  CloseHandle (pi.hThread);
+	  helper_goodbye = goodbye;
+	  helper_pid = pi.dwProcessId;
+	  helper_h_process = pi.hProcess;
+	}
+      else
+	{
+	  CloseHandle (hello);
+	  CloseHandle (goodbye);
+	}
+      DeleteProcThreadAttributeList (si.lpAttributeList);
+      HeapFree (GetProcessHeap (), 0, si.lpAttributeList);
+    }
+
   master_fwd_thread = new cygthread (::pty_master_fwd_thread, this, "ptymf");
   if (!master_fwd_thread)
     {
@@ -3875,6 +3940,7 @@ fhandler_pty_master::get_master_fwd_thread_param (master_fwd_thread_param_t *p)
   p->from_slave_nat = from_slave_nat;
   p->output_mutex = output_mutex;
   p->ttyp = get_ttyp ();
+  p->helper_pid = helper_pid;
   SetEvent (thread_param_copied_event);
 }
 
diff --git a/winsup/cygwin/wincap.cc b/winsup/cygwin/wincap.cc
index 6c79d87..af34de5 100644
--- a/winsup/cygwin/wincap.cc
+++ b/winsup/cygwin/wincap.cc
@@ -51,6 +51,7 @@ wincaps wincap_vista __attribute__((section (".cygwin_dll_common"), shared)) = {
     has_linux_tcp_keepalive_sockopts:false,
     has_tcp_maxrtms:false,
     has_query_process_handle_info:false,
+    has_broken_attach_console:true,
   },
 };
 
@@ -87,6 +88,7 @@ wincaps wincap_7 __attribute__((section (".cygwin_dll_common"), shared)) = {
     has_linux_tcp_keepalive_sockopts:false,
     has_tcp_maxrtms:false,
     has_query_process_handle_info:false,
+    has_broken_attach_console:true,
   },
 };
 
@@ -123,6 +125,7 @@ wincaps wincap_8 __attribute__((section (".cygwin_dll_common"), shared)) = {
     has_linux_tcp_keepalive_sockopts:false,
     has_tcp_maxrtms:false,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -159,6 +162,7 @@ wincaps wincap_8_1 __attribute__((section (".cygwin_dll_common"), shared)) = {
     has_linux_tcp_keepalive_sockopts:false,
     has_tcp_maxrtms:false,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -195,6 +199,7 @@ wincaps  wincap_10_1507 __attribute__((section (".cygwin_dll_common"), shared))
     has_linux_tcp_keepalive_sockopts:false,
     has_tcp_maxrtms:false,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -231,6 +236,7 @@ wincaps  wincap_10_1607 __attribute__((section (".cygwin_dll_common"), shared))
     has_linux_tcp_keepalive_sockopts:false,
     has_tcp_maxrtms:true,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -267,6 +273,7 @@ wincaps wincap_10_1703 __attribute__((section (".cygwin_dll_common"), shared)) =
     has_linux_tcp_keepalive_sockopts:false,
     has_tcp_maxrtms:true,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -303,6 +310,7 @@ wincaps wincap_10_1709 __attribute__((section (".cygwin_dll_common"), shared)) =
     has_linux_tcp_keepalive_sockopts:true,
     has_tcp_maxrtms:true,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -339,6 +347,7 @@ wincaps wincap_10_1803 __attribute__((section (".cygwin_dll_common"), shared)) =
     has_linux_tcp_keepalive_sockopts:true,
     has_tcp_maxrtms:true,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -375,6 +384,7 @@ wincaps wincap_10_1809 __attribute__((section (".cygwin_dll_common"), shared)) =
     has_linux_tcp_keepalive_sockopts:true,
     has_tcp_maxrtms:true,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
@@ -411,6 +421,7 @@ wincaps wincap_10_1903 __attribute__((section (".cygwin_dll_common"), shared)) =
     has_linux_tcp_keepalive_sockopts:true,
     has_tcp_maxrtms:true,
     has_query_process_handle_info:true,
+    has_broken_attach_console:false,
   },
 };
 
diff --git a/winsup/cygwin/wincap.h b/winsup/cygwin/wincap.h
index 7249b95..63911d0 100644
--- a/winsup/cygwin/wincap.h
+++ b/winsup/cygwin/wincap.h
@@ -45,6 +45,7 @@ struct wincaps
     unsigned has_linux_tcp_keepalive_sockopts			: 1;
     unsigned has_tcp_maxrtms					: 1;
     unsigned has_query_process_handle_info			: 1;
+    unsigned has_broken_attach_console				: 1;
   };
 };
 
@@ -113,6 +114,7 @@ public:
   bool	IMPLEMENT (has_linux_tcp_keepalive_sockopts)
   bool	IMPLEMENT (has_tcp_maxrtms)
   bool	IMPLEMENT (has_query_process_handle_info)
+  bool	IMPLEMENT (has_broken_attach_console)
 
   void disable_case_sensitive_dirs ()
   {
diff --git a/winsup/utils/mingw/cygwin-console-helper.cc b/winsup/utils/mingw/cygwin-console-helper.cc
index 66004bd..80d15e3 100644
--- a/winsup/utils/mingw/cygwin-console-helper.cc
+++ b/winsup/utils/mingw/cygwin-console-helper.cc
@@ -6,11 +6,11 @@ main (int argc, char **argv)
   char *end;
   if (argc < 3)
     exit (1);
+  SetConsoleCtrlHandler (NULL, TRUE);
   HANDLE h = (HANDLE) strtoull (argv[1], &end, 0);
   SetEvent (h);
   if (argc == 4) /* Pseudo console helper mode for PTY */
     {
-      SetConsoleCtrlHandler (NULL, TRUE);
       HANDLE hPipe = (HANDLE) strtoull (argv[3], &end, 0);
       char buf[64];
       sprintf (buf, "StdHandles=%p,%p\n",