[PATCH 12/11] vt: remove zero-white-space handling from conv_uni_to_pc()

Nicolas Pitre
2025-04-10T19:38:16Z

From: Nicolas Pitre <npitre@baylibre.com>

This is now taken care of by ucs_is_zero_width(). And in the case where
we do want a padding from some zero-width code point then we should also
give the legacy displays a space character to work with.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
---

This is a fix for a small issue discovered during everyday usage.
I didn't think it is worth resending the whole series for this but
if you prefer otherwise please let me know.

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 82d70083fe..bb4bb272eb 100644
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -870,8 +870,6 @@ int conv_uni_to_pc(struct vc_data *conp, long ucs)
return -4; /* Not found */
else if (ucs < 0x20)
return -1; /* Not a printable character */
- else if (ucs == 0xfeff || (ucs >= 0x200b && ucs <= 0x200f))
- return -2; /* Zero-width space */
/*
* UNI_DIRECT_BASE indicates the start of the region in the User Zone
* which always has a 1:1 mapping to the currently loaded font. The
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index dc84f9c6b7..0d1d663c78 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2964,13 +2964,15 @@ static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
goto out;
}
}
+ /* padding for the legacy display like done below */
+ tc = ' ';
}
}

/* Now try to find out how to display it */
tc = conv_uni_to_pc(vc, tc);
if (tc & ~charmask) {
- if (tc == -1 || tc == -2)
+ if (tc == -1)
return -1; /* nothing to display */

/* Glyph not found */