bpo-36698: IDLE no longer fails when write non-encodable characters to stderr. (GH-16583)

It now escapes them with a backslash, as the regular Python interpreter.
Added the "errors" field to the standard streams.
(cherry picked from commit b690a2759e62d9ee0b6ea1b20e8f7e4b2cdbf8bb)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

1 files changed, 18 insertions, 23 deletions

diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index b9e813b..b5533be 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -15,6 +15,7 @@ from idlelib.config import idleConf
 
 if idlelib.testing:  # Set True by test.test_idle to avoid setlocale.
     encoding = 'utf-8'
+    errors = 'surrogateescape'
 else:
     # Try setting the locale, so that we can find out
     # what encoding to use
@@ -24,15 +25,9 @@ else:
     except (ImportError, locale.Error):
         pass
 
-    locale_decode = 'ascii'
     if sys.platform == 'win32':
-        # On Windows, we could use "mbcs". However, to give the user
-        # a portable encoding name, we need to find the code page
-        try:
-            locale_encoding = locale.getdefaultlocale()[1]
-            codecs.lookup(locale_encoding)
-        except LookupError:
-            pass
+        encoding = 'utf-8'
+        errors = 'surrogateescape'
     else:
         try:
             # Different things can fail here: the locale module may not be
@@ -40,30 +35,30 @@ else:
             # resulting codeset may be unknown to Python. We ignore all
             # these problems, falling back to ASCII
             locale_encoding = locale.nl_langinfo(locale.CODESET)
-            if locale_encoding is None or locale_encoding == '':
-                # situation occurs on macOS
-                locale_encoding = 'ascii'
-            codecs.lookup(locale_encoding)
+            if locale_encoding:
+                codecs.lookup(locale_encoding)
         except (NameError, AttributeError, LookupError):
             # Try getdefaultlocale: it parses environment variables,
             # which may give a clue. Unfortunately, getdefaultlocale has
             # bugs that can cause ValueError.
             try:
                 locale_encoding = locale.getdefaultlocale()[1]
-                if locale_encoding is None or locale_encoding == '':
-                    # situation occurs on macOS
-                    locale_encoding = 'ascii'
-                codecs.lookup(locale_encoding)
+                if locale_encoding:
+                    codecs.lookup(locale_encoding)
             except (ValueError, LookupError):
                 pass
 
-    locale_encoding = locale_encoding.lower()
-
-    encoding = locale_encoding
-    # Encoding is used in multiple files; locale_encoding nowhere.
-    # The only use of 'encoding' below is in _decode as initial value
-    # of deprecated block asking user for encoding.
-    # Perhaps use elsewhere should be reviewed.
+        if locale_encoding:
+            encoding = locale_encoding.lower()
+            errors = 'strict'
+        else:
+            # POSIX locale or macOS
+            encoding = 'ascii'
+            errors = 'surrogateescape'
+        # Encoding is used in multiple files; locale_encoding nowhere.
+        # The only use of 'encoding' below is in _decode as initial value
+        # of deprecated block asking user for encoding.
+        # Perhaps use elsewhere should be reviewed.
 
 coding_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)', re.ASCII)
 blank_re = re.compile(r'^[ \t\f]*(?:[#\r\n]|$)', re.ASCII)