From 717db9fd1ce369d5279480613bcf61daf658309a Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Sat, 2 May 2020 15:03:07 +0200 Subject: [PATCH] setup_pseudoconsole(): handle missing/incorrect helper gracefully When `cygwin-console-helper.exe` is either missing, or corresponds to a different Cygwin runtime, we currently wait forever while setting up access to the pseudo console, even long after the process is gone that was supposed to signal that it set up access to the pseudo console. Let's handle that more gracefully: if the process exited without signaling, we cannot use the pseudo console. In that case, let's just fall back to not using it. Signed-off-by: Johannes Schindelin --- winsup/cygwin/fhandler_tty.cc | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc index b2e725d5d..8547ec7c4 100644 --- a/winsup/cygwin/fhandler_tty.cc +++ b/winsup/cygwin/fhandler_tty.cc @@ -3496,7 +3496,23 @@ fhandler_pty_master::setup_pseudoconsole () TRUE, EXTENDED_STARTUPINFO_PRESENT, NULL, NULL, &si_helper.StartupInfo, &pi_helper)) goto cleanup_event_and_pipes; - WaitForSingleObject (hello, INFINITE); + for (;;) + { + DWORD wait_result = WaitForSingleObject (hello, 500); + if (wait_result == WAIT_OBJECT_0) + break; + if (wait_result != WAIT_TIMEOUT) + goto cleanup_helper_process; + DWORD exit_code; + if (!GetExitCodeProcess(pi_helper.hProcess, &exit_code)) + goto cleanup_helper_process; + if (exit_code == STILL_ACTIVE) + continue; + if (exit_code != 0 || + WaitForSingleObject (hello, 500) != WAIT_OBJECT_0) + goto cleanup_helper_process; + break; + } CloseHandle (hello); CloseHandle (pi_helper.hThread); /* Retrieve pseudo console handles */