Fix NO-BREAK SPACE (U+00A0) column width calculation#448
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migueldeicaza merged 2 commits intomigueldeicaza:mainfrom Jan 16, 2026
Merged
Fix NO-BREAK SPACE (U+00A0) column width calculation#448migueldeicaza merged 2 commits intomigueldeicaza:mainfrom
migueldeicaza merged 2 commits intomigueldeicaza:mainfrom
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The condition `irune <= 0xA0` incorrectly treated U+00A0 (NO-BREAK SPACE) as non-printable, returning width -1. This caused cursor positioning issues in applications that use NBSP in their output. Changed to `irune < 0xA0` so that NO-BREAK SPACE correctly returns width 1 (handled by the default case at end of function), matching the behavior of regular space (U+0020).
Verifies that NBSP has width 1 and cursor positioning works correctly when NBSP is used (e.g., after prompt characters like in Claude Code).
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Let me first validate with ucs-detect |
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Good news, that passed. |
yejune
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* Fix NO-BREAK SPACE (U+00A0) column width calculation The condition `irune <= 0xA0` incorrectly treated U+00A0 (NO-BREAK SPACE) as non-printable, returning width -1. This caused cursor positioning issues in applications that use NBSP in their output. Changed to `irune < 0xA0` so that NO-BREAK SPACE correctly returns width 1 (handled by the default case at end of function), matching the behavior of regular space (U+0020). * Add test for NO-BREAK SPACE (U+00A0) width Verifies that NBSP has width 1 and cursor positioning works correctly when NBSP is used (e.g., after prompt characters like in Claude Code).
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Summary
NO-BREAK SPACE (U+00A0) was incorrectly treated as non-printable (width -1) because the condition
irune <= 0xA0included it in the C1 control character range. This caused cursor positioning issues when applications use NBSP in their output.Changes
Changed the condition from
irune <= 0xA0toirune < 0xA0incolumnWidth()so that U+00A0 falls through to the default return value of 1, matching the expected behavior of a space character.Use Case
Claude Code (Anthropic's terminal-based AI coding assistant) uses NO-BREAK SPACE after its prompt character (
❯). With the incorrect width calculation, typing the first character after the prompt would cause cursor misalignment and visual glitches (duplicate/ghost characters).Testing