Skip to content

[3.11] gh-82052: Don't send partial UTF-8 sequences to the Windows API (GH-101103) #101107

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 17, 2023
Merged

[3.11] gh-82052: Don't send partial UTF-8 sequences to the Windows API (GH-101103) #101107

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Windows/2023-01-17-18-17-58.gh-issue-82052.mWyysT.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Fixed an issue where writing more than 32K of Unicode output to the console screen in one go can result in mojibake.
17 changes: 16 additions & 1 deletion Modules/_io/winconsoleio.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -954,7 +954,7 @@ _io__WindowsConsoleIO_write_impl(winconsoleio *self, Py_buffer *b)
{
BOOL res = TRUE;
wchar_t *wbuf;
DWORD len, wlen, n = 0;
DWORD len, wlen, orig_len, n = 0;
HANDLE handle;

if (self->fd == -1)
Expand Down Expand Up @@ -984,6 +984,21 @@ _io__WindowsConsoleIO_write_impl(winconsoleio *self, Py_buffer *b)
have to reduce and recalculate. */
while (wlen > 32766 / sizeof(wchar_t)) {
len /= 2;
orig_len = len;
/* Reduce the length until we hit the final byte of a UTF-8 sequence
* (top bit is unset). Fix for github issue 82052.
*/
while (len > 0 && (((char *)b->buf)[len-1] & 0x80) != 0)
--len;
/* If we hit a length of 0, something has gone wrong. This shouldn't
* be possible, as valid UTF-8 can have at most 3 non-final bytes
* before a final one, and our buffer is way longer than that.
* But to be on the safe side, if we hit this issue we just restore
* the original length and let the console API sort it out.
*/
if (len == 0) {
len = orig_len;
}
wlen = MultiByteToWideChar(CP_UTF8, 0, b->buf, len, NULL, 0);
}
Py_END_ALLOW_THREADS
Expand Down