[Bug #1552726] Avoid unnecessary polling at the interpreter prompt when certain versions of readline are being used
diff --git a/Misc/NEWS b/Misc/NEWS
index eeab829..9876af9 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -139,6 +139,8 @@
- Modifying an empty deque during iteration now raises RuntimeError
instead of StopIteration.
+- Bug #1552726: fix polling at the interpreter prompt when certain
+ versions of the readline library are in use.
Library
-------
diff --git a/Modules/readline.c b/Modules/readline.c
index 92f2d1f..853874b 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -768,10 +768,16 @@
while (!has_input)
{ struct timeval timeout = {0, 100000}; /* 0.1 seconds */
+
+ /* [Bug #1552726] Only limit the pause if an input hook has been
+ defined. */
+ struct timeval *timeoutp = NULL;
+ if (PyOS_InputHook)
+ timeoutp = &timeout;
FD_SET(fileno(rl_instream), &selectset);
/* select resets selectset if no input was available */
has_input = select(fileno(rl_instream) + 1, &selectset,
- NULL, NULL, &timeout);
+ NULL, NULL, timeoutp);
if(PyOS_InputHook) PyOS_InputHook();
}