From: Nicolas Pitre Date: Thu, 10 Apr 2025 01:14:03 +0000 (-0400) Subject: vt: pad double-width code points with a zero-white-space X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=547f57b88d5f2ad4e9ab5e0d63a668467c10c736;p=users%2Fjedix%2Flinux-maple.git vt: pad double-width code points with a zero-white-space In the Unicode screen buffer, we follow double-width code points with a space to maintain proper column alignment. This, however, creates semantic problems when e.g. using cut and paste or selection. Let's use a better code point for the column padding's purpose i.e. a zero-white-space rather than a full space. Signed-off-by: Nicolas Pitre Link: https://lore.kernel.org/r/20250410011839.64418-12-nico@fluxnic.net Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index e3d35c4f92045..dc84f9c6b7c62 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2937,12 +2937,13 @@ static int vc_con_write_normal(struct vc_data *vc, int tc, int c, width = 2; } else if (ucs_is_zero_width(c)) { prev_c = vc_uniscr_getc(vc, -1); - if (prev_c == ' ' && + if (prev_c == 0x200B && ucs_is_double_width(vc_uniscr_getc(vc, -2))) { /* * Let's merge this zero-width code point with * the preceding double-width code point by - * replacing the existing whitespace padding. + * replacing the existing zero-white-space + * padding. */ vc_con_rewind(vc); } else if (c == 0xfe0f && prev_c != 0) { @@ -3040,7 +3041,11 @@ static int vc_con_write_normal(struct vc_data *vc, int tc, int c, tc = conv_uni_to_pc(vc, ' '); if (tc < 0) tc = ' '; - next_c = ' '; + /* + * Store a zero-white-space in the Unicode screen given that + * the previous code point is semantically double-width. + */ + next_c = 0x200B; } out: