* path.cc (path_conv::check): Leave symlink expansion loop in case

a not-ENOENT error happens.

	* cygheap.h (cygheap_fdmanip::fhandler_pipe *): New cast operator.
	* pinfo.cc (_pinfo::commune_recv): Add PICOM_PIPE_FHANDLER handling.
	(_pinfo::commune_send): Ditto.
	(_pinfo::pipe_fhandler): New method.
	* pinfo.h (enum picom): Add PICOM_PIPE_FHANDLER.
	(_pinfo::pipe_fhandler): Declare.
	* pipe.cc (fhandler_pipe::open): Rewrite.  Allow to open foreign
	pipe handles.

winsup/cygwin/path.cc

@@ -764,6 +764,11 @@ is_virtual_symlink:
 		  else
 		    break;
 		}
+	      else if (sym.error != ENOENT) /* E. g. EACCES */
+		{
+		  error = sym.error;
+		  goto out;
+		}
 	      /* No existing file found. */
 	    }