From e62dfabc829cd3302da2e0cbc4efdb68a5413ca2 Mon Sep 17 00:00:00 2001
From: Benedek Racz <betontalpfa@gmail.com>
Date: Fri, 24 Jan 2020 16:24:03 +0100
Subject: [PATCH] [FIX] process termination: do not terminate a process, which
 has not been started.

---
 wexpect/spawn.py        | 13 +++++++++----
 wexpect/wexpect_util.py |  2 +-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/wexpect/spawn.py b/wexpect/spawn.py
index 1376cd0..33ed162 100644
--- a/wexpect/spawn.py
+++ b/wexpect/spawn.py
@@ -292,10 +292,11 @@ class SpawnBase:
         
         try:
             logger.info('Deleting...')
-            self.terminate()
-            self.disconnect_from_child()
-            if self.safe_exit:
-                self.wait()
+            if self.child_process is not None:
+                self.terminate()
+                self.disconnect_from_child()
+                if self.safe_exit:
+                    self.wait()
         except:
             traceback.print_exc()
             logger.warning(traceback.format_exc())
@@ -425,6 +426,10 @@ class SpawnBase:
     def isalive(self, console=True):
         """True if the child is still alive, false otherwise"""
         
+        if self.child_process is None:
+            # Child process has not been started... Not alive
+            return False
+        
         try:
             self.exitstatus = self.child_process.wait(timeout=0)
         except psutil.TimeoutExpired:
diff --git a/wexpect/wexpect_util.py b/wexpect/wexpect_util.py
index 509ba90..cbedbbc 100644
--- a/wexpect/wexpect_util.py
+++ b/wexpect/wexpect_util.py
@@ -162,7 +162,7 @@ class ExceptionPexpect(Exception):
     def __filter_not_wexpect(self, trace_list_item):
         """This returns True if list item 0 the string 'wexpect.py' in it. """
 
-        if trace_list_item[0].find('wexpect.py') == -1:
+        if trace_list_item[0].find('spawn.py') == -1:
             return True
         else:
             return False