gh-156207: Fix curses Textbox.gather() for double-width characters - #156208
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gather() read the window one cell at a time, so the second cell of a double-width character was reported as another copy of it. Read each line with in_wchstr() instead: its count is a cell count, and it skips the continuation cell.
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This all is right, but using the new API allows us to go further. We no longer need move() + _end_of_line(y) to get the count here. We can simply read to the end of line and then strip redundant spaces (except one). Probably we can even use in_wstr().
in_wstr() reads a line to its end, so gather() no longer needs move() + _end_of_line() to work out how much of it to ask for: strip the trailing blanks instead, keeping the one the cursor rests on.
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Thanks, done. |
| # reads a whole line at a time so that the second cell, which holds | ||
| # the same character, is not reported as another one. | ||
| text = '你好' | ||
| if self._encodable(text): |
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Skip the test if it is not encodable.
| for ch in text: | ||
| box.do_command(ch) | ||
| self.assertEqual(box.gather(), text + ' ') | ||
| box, win = self._make_textbox(1, 12, stripspaces=0) |
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stripspaces is boolean.
serhiy-storchaka
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Aug 25, 2026
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LGTM. 👍
Thank you for your contribution @fedonman.
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@fedonman, please say your AI to restore the bedevere links. |
clin1234
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Aug 27, 2026
…ers (pythonGH-156208) gather() read the window cell by cell, so a double-width character, which occupies two cells, was returned twice. Read the whole line with in_wstr(), which returns every character once.
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gather()now reads each line within_wchstr(), whose count is a cell count and which skips a double-width character's continuation cell, instead of reading one cell at a time and reporting that second cell as another copy of the character.This fixes only the
gather()symptom of gh-156207. The insert-mode corruption and thecurses.errorat the last column are untouched: both need_insert_printable_char()to know a character's display width, which is a larger change.The duplication only exists on the main branch, where
gather()started reading cells within_wch(), so there is no NEWS entry.