Issue #11650: PyOS_StdioReadline() retries fgets() if it was interrupted

(EINTR), for example if the program is stopped with CTRL+z on Mac OS X. Patch
written by Charles-Francois Natali.

Misc/NEWS

@@ -10,6 +10,10 @@ What's New in Python 3.1.4?
 Core and Builtins
 -----------------
 
+- Issue #11650: PyOS_StdioReadline() retries fgets() if it was interrupted
+  (EINTR), for example if the program is stopped with CTRL+z on Mac OS X. Patch
+  written by Charles-Francois Natali.
+
 - Issue #8651: PyArg_Parse*() functions raise an OverflowError if the file
   doesn't have PY_SSIZE_T_CLEAN define and the size doesn't fit in an int
   (length bigger than 2^31-1 bytes).

Parser/myreadline.c

@@ -36,7 +36,7 @@ static int
 my_fgets(char *buf, int len, FILE *fp)
 {
     char *p;
-    for (;;) {
+    while (1) {
         if (PyOS_InputHook != NULL)
             (void)(PyOS_InputHook)();
         errno = 0;
@@ -85,9 +85,10 @@ my_fgets(char *buf, int len, FILE *fp)
 #ifdef WITH_THREAD
             PyEval_SaveThread();
 #endif
-            if (s < 0) {
+            if (s < 0)
                     return 1;
-            }
+            /* try again */
+            continue;
         }
 #endif
         if (PyOS_InterruptOccurred()) {