gh-153864: Fix curses window.insch() for non-ASCII characters on a wide build#153865
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gh-153864: Fix curses window.insch() for non-ASCII characters on a wide build#153865serhiy-storchaka wants to merge 1 commit into
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…n a wide build On a wide build, winsch() does not locale-decode a byte above 127, unlike waddch(), so insch() inserted '¤' (U+00A4) instead of '€' for byte 0xA4 under ISO-8859-15. Decode the byte with btowc() and insert it as a wide character, like addch(). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
vstinner
approved these changes
Jul 18, 2026
| if (type == 1) { | ||
| /* winsch() does not locale-decode a byte above 127 on a wide build, | ||
| unlike waddch(), so decode it here and insert it as a wide | ||
| character. */ |
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On a wide (
ncursesw) build,window.insch()andwindow.mvinsch()insert a non-ASCIIint/bytesbyte as its Latin-1 code point instead of decoding it through the window's encoding, unlikeaddch()— e.g.insch(0xA4)under ISO-8859-15 inserts¤(U+00A4) whileaddch(0xA4)inserts€.The cause is in ncurses:
winsch()has a fast path for a printable 8-bit byte that stores it directly as a code point, bypassing the locale decodewaddch()performs. The fix decodes the byte withbtowc()(the inverse ofinch()'swctob()) and inserts it withwins_wch(); a byte with no single-byte form in the locale falls back towinsch().The underlying ncurses behavior was reported upstream.