closes bpo-38156: Always handle interrupts in PyOS_StdioReadline. (GH-21569)
This consolidates the handling of my_fgets return values, so that interrupts are always handled, even if they come after EOF.
I believe PyOS_StdioReadline is still buggy in that I/O errors will not result in a proper Python exception being set. However, that is a separate issue.
(cherry picked from commit a74eea238f5baba15797e2e8b570d153bc8690a7)
Co-authored-by: Benjamin Peterson <benjamin@python.org>
diff --git a/Parser/myreadline.c b/Parser/myreadline.c
index 2dd3623..a49c9d8 100644
--- a/Parser/myreadline.c
+++ b/Parser/myreadline.c
@@ -291,37 +291,16 @@
}
#endif
- n = 100;
- p = (char *)PyMem_RawMalloc(n);
- if (p == NULL) {
- PyEval_RestoreThread(tstate);
- PyErr_NoMemory();
- PyEval_SaveThread();
- return NULL;
- }
-
fflush(sys_stdout);
if (prompt) {
fprintf(stderr, "%s", prompt);
}
fflush(stderr);
- switch (my_fgets(tstate, p, (int)n, sys_stdin)) {
- case 0: /* Normal case */
- break;
- case 1: /* Interrupt */
- PyMem_RawFree(p);
- return NULL;
- case -1: /* EOF */
- case -2: /* Error */
- default: /* Shouldn't happen */
- *p = '\0';
- break;
- }
-
- n = strlen(p);
- while (n > 0 && p[n-1] != '\n') {
- size_t incr = n+2;
+ n = 0;
+ p = NULL;
+ do {
+ size_t incr = (n > 0) ? n + 2 : 100;
if (incr > INT_MAX) {
PyMem_RawFree(p);
PyEval_RestoreThread(tstate);
@@ -329,7 +308,6 @@
PyEval_SaveThread();
return NULL;
}
-
pr = (char *)PyMem_RawRealloc(p, n + incr);
if (pr == NULL) {
PyMem_RawFree(p);
@@ -339,12 +317,18 @@
return NULL;
}
p = pr;
-
- if (my_fgets(tstate, p+n, (int)incr, sys_stdin) != 0) {
+ int err = my_fgets(tstate, p + n, incr, sys_stdin);
+ if (err == 1) {
+ // Interrupt
+ PyMem_RawFree(p);
+ return NULL;
+ } else if (err != 0) {
+ // EOF or error
+ p[n] = '\0';
break;
}
- n += strlen(p+n);
- }
+ n += strlen(p + n);
+ } while (p[n-1] != '\n');
pr = (char *)PyMem_RawRealloc(p, n+1);
if (pr == NULL) {