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Merge surrogate pairs in Windows VT100 console input - #2124
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Cherith1222 wants to merge 1 commit into
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Since 3.0.49, Windows uses Vt100ConsoleInputReader when virtual terminal input is available. The console reports a non-BMP character such as U+1F132 as two key events, one per UTF-16 surrogate. The VT100 reader fed both halves to the parser separately, so pasting such a character inserted two lone surrogates (shown as '??'). The legacy ConsoleInputReader already merges these pairs. Merge them in the VT100 reader too, before feeding the parser. Fixes prompt-toolkit#1978 AI-assisted (Cursor). Not yet reviewed by a human.
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Summary
Issue #1978 reports that pasting U+1F132 in Windows Terminal started inserting
??in prompt-toolkit 3.0.49. When virtual terminal input is enabled,Win32InputusesVt100ConsoleInputReader. The console delivers that character as two key events, a high and a low UTF-16 surrogate.ConsoleInputReader.readalready merges the pair in_merge_paired_surrogates.Vt100ConsoleInputReader.readfed each half to the VT100 parser by itself. It now joins the key data from that read and runsencode("utf-16-le", "surrogatepass").decode("utf-16-le", "surrogatepass"), so a high/low pair becomes one character beforefeed.tests/test_win32_input.pyfeedsa,\ud83c,\udd32, andbthrough a fakeReadConsoleInputWand expects the keysa, U+1F132, andb. The test is skipped unlesssys.platform == "win32".On 2026-10-08,
ghfor headadda06422be35dd290ac04404af982dd76030ef0showed sixtest-ubunturuns (3.10, 3.11, 3.12, 3.13, 3.14, 3.14t), all success. Those jobs do not run this test.Fixes #1978.
Drafted with Cursor.
Cherith reviewed this diff and confirmed it with the person who helped draft it.