Fix newline handling in stdout and stderr

Changes requested by sebastinas
bpython · sebastinas · May 28, 2017 · sebastinas · May 28, 2017 · ata2001
diff --git a/bpython/curtsiesfrontend/repl.py b/bpython/curtsiesfrontend/repl.py
    def send_to_stdout(self, output):
        """Send unicode string to Repl stdout"""
+        if not output: return
diff --git a/bpython/curtsiesfrontend/repl.py b/bpython/curtsiesfrontend/repl.py
@@ -1157,9 +1165,16 @@ def send_to_stderr(self, error):

        Must be able to handle FmtStrs because interpreter pass in
        tracebacks already formatted."""
+        if not error: return
diff --git a/bpython/curtsiesfrontend/repl.py b/bpython/curtsiesfrontend/repl.py
        lines = output.split('\n')
+        if output == len(output) * '\n':
+            # If the string consist only of newline characters,
+            # str.split returns one more empty strings.
diff --git a/bpython/curtsiesfrontend/repl.py b/bpython/curtsiesfrontend/repl.py
+        if error == len(error) * '\n':
+            # If the string consist only of newline characters,
+            # str.split returns one more empty strings.
+            lines = lines[:-1]