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
This commit is contained in:
NRK 2024-07-04 21:27:47 +00:00 committed by Hiltjo Posthuma
parent 51e32d49b5
commit 59936c7d97

19
drw.c
View File

@ -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[] = "<EFBFBD>";
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);