shelldriver: Move password handling into main poll loop

Moving the password handling into the main loop allows it to follow the
same timeout handling logic as other prompts. Specifically, if no output
is seen an empty newline will be sent instead of waiting indefinitely
for a timeout. This prevents test timeout errors when other output is
intermingled with the password prompting or the main prompt after
entering the password.

Signed-off-by: Joshua Watt <Joshua.Watt@garmin.com>

Author: JoshuaWatt

labgrid/driver/shelldriver.py

@@ -120,7 +120,7 @@ def _await_login(self):
 
         timeout = Timeout(float(self.login_timeout))
 
-        expectations = [self.prompt, self.login_prompt, TIMEOUT]
+        expectations = [self.prompt, self.login_prompt, "Password: ", TIMEOUT]
         if self.console_ready != "":
             expectations.append(self.console_ready)
 
@@ -130,6 +130,7 @@ def _await_login(self):
         # Because pexpect keeps any read data in it's buffer when a timeout
         # occours, we can't lose any data this way.
         last_before = b''
+        did_login = False
 
         while True:
             index, before, _, _ = self.console.expect(
@@ -146,21 +147,15 @@ def _await_login(self):
             elif index == 1:
                 # we need to login
                 self.console.sendline(self.username)
-                index, _, _, _ = self.console.expect([self.prompt, "Password: "], timeout=10)
-                if index == 1:
-                    if self.password:
-                        self.console.sendline(self.password)
-                        self.console.expect(self.prompt, timeout=timeout.remaining)
-                    else:
-                        raise Exception("Password entry needed but no password set")
-
-                if self.post_login_settle_time > 0:
-                    self.console.settle(self.post_login_settle_time, timeout=timeout.remaining)
-
-                self._check_prompt()
-                break
+                did_login = True
 
             elif index == 2:
+                if self.password:
+                    self.console.sendline(self.password)
+                else:
+                    raise Exception("Password entry needed but no password set")
+
+            elif index == 3:
                 # expect hit a timeout while waiting for a match
                 if before == last_before:
                     # we did not receive anything during
@@ -169,7 +164,7 @@ def _await_login(self):
                     # newline to check the state
                     self.console.sendline("")
 
-            elif index == 3:
+            elif index == 4:
                 # we have just activated a console here
                 # lets start over again and see if login or prompt will appear
                 # now.
@@ -180,6 +175,11 @@ def _await_login(self):
             if timeout.expired:
                 raise TIMEOUT("Timeout of {} seconds exceeded during waiting for login".format(self.login_timeout))  # pylint: disable=line-too-long
 
+        if did_login:
+            if self.post_login_settle_time > 0:
+                self.console.settle(self.post_login_settle_time, timeout=timeout.remaining)
+            self._check_prompt()
+
     @step()
     def get_status(self):
         """Returns the status of the shell-driver.