bpo-34485: Enhance init_sys_streams() (GH-8978)

Python now gets the locale encoding with C code to initialize the encoding
of standard streams like sys.stdout. Moreover, the encoding is now
initialized to the Python codec name to get a normalized encoding name and
to ensure that the codec is loaded. The change avoids importing
_bootlocale and _locale modules at startup by default.

When the PYTHONIOENCODING environment variable only contains an encoding,
the error handler is now is now set explicitly to "strict".

Rename also get_default_standard_stream_error_handler() to
get_stdio_errors().

Reduce the buffer to format the "cpXXX" string (Windows locale encoding).

1 files changed, 2 insertions, 2 deletions

diff --git a/Programs/_testembed.c b/Programs/_testembed.c
index f1d30f6..d0c00cf 100644
--- a/Programs/_testembed.c
+++ b/Programs/_testembed.c
@@ -113,9 +113,9 @@ static int test_forced_io_encoding(void)
     printf("--- Set errors only ---\n");
     check_stdio_details(NULL, "ignore");
     printf("--- Set encoding only ---\n");
-    check_stdio_details("latin-1", NULL);
+    check_stdio_details("iso8859-1", NULL);
     printf("--- Set encoding and errors ---\n");
-    check_stdio_details("latin-1", "replace");
+    check_stdio_details("iso8859-1", "replace");
 
     /* Check calling after initialization fails */
     Py_Initialize();