SF patch #1630975: Fix crash when replacing sys.stdout in sitecustomize

When running the interpreter in an environment that would cause it to set
stdout/stderr/stdin's encoding, having a sitecustomize that would replace
them with something other than PyFile objects would crash the interpreter.
Fix it by simply ignoring the encoding-setting for non-files.

This could do with a test, but I can think of no maintainable and portable
way to test this bug, short of adding a sitecustomize.py to the buildsystem
and have it always run with it (hmmm....)

1 files changed, 3 insertions, 3 deletions

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 4970adff50..59f6cfc684 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1087,17 +1087,17 @@ _PySys_Init(void)
 	if (PyErr_Occurred())
 		return NULL;
 #ifdef MS_WINDOWS
-	if(isatty(_fileno(stdin))){
+	if(isatty(_fileno(stdin)) && PyFile_Check(sysin)) {
 		sprintf(buf, "cp%d", GetConsoleCP());
 		if (!PyFile_SetEncoding(sysin, buf))
 			return NULL;
 	}
-	if(isatty(_fileno(stdout))) {
+	if(isatty(_fileno(stdout)) && PyFile_Check(sysout)) {
 		sprintf(buf, "cp%d", GetConsoleOutputCP());
 		if (!PyFile_SetEncoding(sysout, buf))
 			return NULL;
 	}
-	if(isatty(_fileno(stderr))) {
+	if(isatty(_fileno(stderr)) && PyFile_Check(syserr)) {
 		sprintf(buf, "cp%d", GetConsoleOutputCP());
 		if (!PyFile_SetEncoding(syserr, buf))
 			return NULL;