dmenu

commit 59936c7d972587a47d61161279bb8e8abc0b02f3
parent 51e32d49b56c86cd288c64fccf6cd765547781b9
Author: NRK <nrk@disroot.org>
Date:   Thu,  4 Jul 2024 21:27:47 +0000

render invalid utf8 sequences as U+FFFD

previously drw_text would do the width calculations as if
invalid utf8 sequences were replaced with U+FFFD but would pass
the invalid utf8 sequence to xft to render where xft would just
cut it off at the first invalid byte.

this change makes invalid utf8 render as U+FFFD and avoids
sending invalid sequences to xft. the following can be used to
check the behavior before and after the patch:

	$ printf "0\xef1234567\ntest" | dmenu

Ref: https://lists.suckless.org/dev/2407/35646.html

Diffstat:
M
drw.c
 | 
19
+++++++++++++++----

1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drw.c b/drw.c
@@ -237,7 +237,8 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 	XftResult result;
 	int charexists = 0, overflow = 0;
 	/* keep track of a couple codepoints for which we have no match. */
-	static unsigned int nomatches[128], ellipsis_width;
+	static unsigned int nomatches[128], ellipsis_width, invalid_width;
+	static const char invalid[] = "�";
 
 	if (!drw || (render && (!drw->scheme || !w)) || !text || !drw->fonts)
 		return 0;
@@ -257,6 +258,10 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 	usedfont = drw->fonts;
 	if (!ellipsis_width && render)
 		ellipsis_width = drw_fontset_getwidth(drw, "...");
+	if (!invalid_width) {
+		invalid_width = -1; /* stop infinite recursion */
+		invalid_width = drw_fontset_getwidth(drw, invalid);
+	}
 	while (1) {
 		ew = ellipsis_len = utf8err = utf8charlen = utf8strlen = 0;
 		utf8str = text;
@@ -284,9 +289,9 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 						else
 							utf8strlen = ellipsis_len;
 					} else if (curfont == usedfont) {
-						utf8strlen += utf8charlen;
 						text += utf8charlen;
-						ew += tmpw;
+						utf8strlen += utf8err ? 0 : utf8charlen;
+						ew += utf8err ? 0 : tmpw;
 					} else {
 						nextfont = curfont;
 					}
@@ -294,7 +299,7 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 				}
 			}
 
-			if (overflow || !charexists || nextfont)
+			if (overflow || !charexists || nextfont || utf8err)
 				break;
 			else
 				charexists = 0;
@@ -309,6 +314,12 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lp
 			x += ew;
 			w -= ew;
 		}
+		if (utf8err && (!render || invalid_width < w)) {
+			if (render)
+				drw_text(drw, x, y, w, h, 0, invalid, invert);
+			x += invalid_width;
+			w -= invalid_width;
+		}
 		if (render && overflow)
 			drw_text(drw, ellipsis_x, y, ellipsis_w, h, 0, "...", invert);