Okay, you seem to be right. Before I upgraded my Ubuntu at the end of
last year I did have this issue there, too. I can assure you that
this /was/ a crash on Linux, and perhaps you've just had a more recent
version of the relevant X libraries since I started on this list.
I know - for certain - that loaded screen fonts are still being
closed, but that is no longer an error condition. It just slows
things down a tiny bit.
Assuming first that you do not have a font that handles Chinese
Extended range E, this is my way to recreate.
#Start st:
#Four default "Source Code Pro" fonts loaded (three are default medium).
#The array frc[] is empty.
#The first block of echo statements will fill up frc[16],
interestingly X simply re-loads the current default font when it
cannot find a glyph.
echo -e "\xf0\xab\xa0\xa0"
echo -e "\xf0\xab\xa0\xa1"
echo -e "\xf0\xab\xa0\xa2"
echo -e "\xf0\xab\xa0\xa3"
echo -e "\xf0\xab\xa0\xa4"
echo -e "\xf0\xab\xa0\xa5"
echo -e "\xf0\xab\xa0\xa6"
echo -e "\xf0\xab\xa0\xa7"
echo -e "\xf0\xab\xa0\xa8"
echo -e "\xf0\xab\xa0\xa9"
echo -e "\xf0\xab\xa0\xaa"
echo -e "\xf0\xab\xa0\xab"
echo -e "\xf0\xab\xa0\xac"
echo -e "\xf0\xab\xa0\xad"
echo -e "\xf0\xab\xa0\xae"
echo -e "\xf0\xab\xa0\xaf"
#Now frc[] has 16 open copies of "Source Code Pro".
#
#The next steps is tricker since everyone has a different fontconfig.
Find two glyphs that you DO have fonts for, but are not represented in
your default font. For me, "Place of Interest" works nicely.
echo -e "\xe2\x8c\x98"
# Now frc[15] has closed its unused "Source Code Pro", and instead has
opened up "Segoe UI Symbol".
# Since THAT copy of "Source Code Pro" isn't on screen this never caused harm.
# (it was only held open to keep track of "\xf0\xab\xa0\xaf")
# That means, though, that printing anything new that doesn't use an
already open font will close
# "Segoe UI Symbol" and open that new font.
# Have some smiley shades
echo -e "\xf0\x9f\x98\x8e"
I hope that makes sense.
Thanks,
Gary
On Wed, Mar 21, 2018 at 3:35 PM, Hiltjo Posthuma <hiltjo_AT_codemadness.org> wrote:
> On Wed, Mar 21, 2018 at 02:18:53PM -0400, Gary Allen Vollink wrote:
>> This patch is over my previous simplification patch
>> (https://lists.suckless.org/dev/1803/32601.html), though it could be
>> reworked to go in without it.
>>
>> Problem: When working with text from many languages, it does not take long
>> to run out of font slots for Runes that do not exist within any given
>> fontconfig. Currently, each rune that is not part of a default set takes up
>> another font slot (whether or not that rune is even found).I have found that
>> runes in text (not emoji) have a tendency of showing up in sets, for
>> instance a whole block of text may be in Cyrillic, which quickly takes up
>> the 16 slots available for loaded fonts. This is fine until another rune IS
>> found and put on screen. Whenever that happens, the next time a rune isn't
>> found that font is closed and a new one inserted (whether or not that font
>> includes the required glyph). Unloading an on-screen font at the next
>> not-found rune will crash st.
>>
>>
>> What I have is a partial Fix. This patch makes it take longer for this
>> problem to manifest by making sure the limited font slots are not kept open
>> when a glyph cannot be found. Note that this does not really help the issue
>> on MacOS where the noglyph font will always claim a glyph (even though it's
>> nothing but a binarybox). I haven't found a way to fix it completely (on
>> MacOS and/or over long periods of usage on Linux) without writing something
>> that even I think sucks. I personally got over this by /also/ adjusting the
>> size of the frc[] array on my own build. Either way, this is what I have to
>> offer...
>>
>>
>>
>> Patch:
>>
>> Track runes that are not found separately from the Fontcache, frc[], forget
>> not-found runes in fifo, not lifo. Close an opened font if it doesn't
>> include the required glyph (not taking up an frc[] slot).
>>
>>
>> diff -U 3 -p a/x.c b/x.c
>> --- a/x.c 2018-03-21 13:22:53.549236600 -0400
>> +++ b/x.c 2018-03-21 13:32:00.894134500 -0400
>> _AT_@ -3,6 +3,7 @@
>> #include <math.h>
>> #include <limits.h>
>> #include <locale.h>
>> +#include <wchar.h>
>> #include <signal.h>
>> #include <sys/select.h>
>> #include <time.h>
>> _AT_@ -219,9 +220,12 @@ enum {
>> typedef struct {
>> XftFont *font;
>> int flags;
>> - Rune unicodep;
>> } Fontcache;
>>
>> +/* Runes not found array. */
>> +static wchar_t noglyph[1024];
>> +static int noglyphlen = 0;
>> +
>> /* Fontcache is an array now. A new font will be appended to the array. */
>> static Fontcache frc[16];
>> static int frclen = 0;
>> _AT_@ -1145,7 +1149,7 @@ xmakeglyphfontspecs(XftGlyphFontSpec *sp
>> float runewidth = win.cw;
>> Rune rune;
>> FT_UInt glyphidx;
>> - int i, f, numspecs = 0;
>> + int i, f, r, numspecs = 0;
>>
>> for (i = 0, xp = winx, yp = winy + font->ascent; i < len; ++i) {
>> /* Fetch rune and mode for current glyph. */
>> _AT_@ -1177,7 +1181,8 @@ xmakeglyphfontspecs(XftGlyphFontSpec *sp
>>
>> /* Lookup character index with default font. */
>> glyphidx = XftCharIndex(xw.dpy, font->match, rune);
>> - if (glyphidx) {
>> + /* OR if already failed to find a glyph for this rune. */
>> + if ((glyphidx) || (wmemchr(noglyph, rune, noglyphlen))) {
>> specs[numspecs].font = font->match;
>> specs[numspecs].glyph = glyphidx;
>> specs[numspecs].x = (short)xp;
>> _AT_@ -1193,11 +1198,6 @@ xmakeglyphfontspecs(XftGlyphFontSpec *sp
>> /* Everything correct. */
>> if (glyphidx && frc[f].flags == frcflags)
>> break;
>> - /* We got a default font for a not found glyph. */
>> - if (!glyphidx && frc[f].flags == frcflags
>> - && frc[f].unicodep == rune) {
>> - break;
>> - }
>> }
>>
>> /* Nothing was found. Use fontconfig to find matching font.
>> */
>> _AT_@ -1208,7 +1208,6 @@ xmakeglyphfontspecs(XftGlyphFontSpec *sp
>> if (frclen >= LEN(frc)) {
>> frclen = LEN(frc) - 1;
>> XftFontClose(xw.dpy, frc[frclen].font);
>> - frc[frclen].unicodep = 0;
>> }
>>
>> /*
>> _AT_@ -1224,12 +1223,23 @@ xmakeglyphfontspecs(XftGlyphFontSpec *sp
>> }
>> frc[frclen].font = newFont.match;
>> frc[frclen].flags = frcflags;
>> - frc[frclen].unicodep = rune;
>>
>> glyphidx = XftCharIndex(xw.dpy, frc[frclen].font,
>> rune);
>>
>> - f = frclen;
>> - frclen++;
>> + if (!glyphidx) {
>> + XftFontClose(xw.dpy, frc[frclen].font);
>> + if (noglyphlen >= LEN(noglyph)) {
>> + /* Get rid of the oldest not found
>> rune */
>> + for (r=1; r <= LEN(noglyph); r++) {
>> + noglyph[r-1] = noglyph[r];
>> + }
>> + noglyphlen = LEN(noglyph) - 1;
>> + }
>> + noglyph[noglyphlen++] = rune;
>> + } else {
>> + f = frclen;
>> + frclen++;
>> + }
>> }
>>
>> specs[numspecs].font = frc[f].font;
>>
>>
>>
>
> I've never had this issue and cannot reproduce it all (still). Can you
> provide more information? Recently there are some issues reported by users
> using MacOS and st, this makes for wasted debugging sessions: MacOS and it's
> ecosystem is not supported.
>
> There are also some code-style issues in the patch (newFont -> newfont name).
>
> --
> Kind regards,
> Hiltjo
>
Received on Wed Mar 21 2018 - 21:56:45 CET