localedata: add some exceptions to utf8proc widths

Hangul Jamo medial vowels and final consonants are reportedly combining
characters that won't take up any columns on their own and should be
reported as zero-width, so add an exception for these as well to reflect
how they work in practice.  This conforms to how other implementations
(e.g., glibc) treat these characters.

Reviewed by:	bapt (earlier version), jkim
Sponsored by:	Klara, Inc.

(cherry picked from commit 160c36eae41afa3c4944ed44778c2b48db8fbb77)

1 files changed, 17 insertions, 1 deletions

diff --git a/tools/tools/locale/tools/getwidths.c b/tools/tools/locale/tools/getwidths.c
index 2790b8031912..63c62791253f 100644
--- a/tools/tools/locale/tools/getwidths.c
+++ b/tools/tools/locale/tools/getwidths.c
@@ -28,6 +28,21 @@
 
 #include <utf8proc.h>
 
+static int
+width_of(int32_t wc)
+{
+
+	/*
+	 * Hangul Jamo medial vowels and final consonants are more of
+	 * a combining character, and should be considered zero-width.
+	 */
+	if (wc >= 0x1160 && wc <= 0x11ff)
+		return (0);
+
+	/* No override by default, trust utf8proc's width. */
+	return (utf8proc_charwidth(wc));
+}
+
 int
 main(void)
 {
@@ -43,9 +58,10 @@ main(void)
 		wcc = utf8proc_category(wc);
 		if (wcc == UTF8PROC_CATEGORY_CC)
 			continue;
-		wcw = utf8proc_charwidth(wc);
+		wcw = width_of(wc);
 		if (wcw == 1)
 			continue;
+
 		printf("%04X %d\n", wc, wcw);
 	}