Fixed 'missing glyph doesn't use fontconfig config substitutions' bug

XftFontMatch does display-specific font configuration (commit 528241a).
Nice. Unfortunately, when we switched from FcFontMatch, we also stopped
storing the post-Fc{Config,Default}Substitute FcPattern for future
lookups. The result is that if a glyph isn't found in the primary font,
secondary font lookups use the original FcPattern, not the configured
one. If you have custom fontconfig rules (like me), this can be
disappointing.

I basically just copied the guts out of XftFontMatch[1] and saved
the intermediate configured FcPattern. Could be related to the bug that
inspired commit 4242027.

[1]: https://cgit.freedesktop.org/xorg/lib/libXft/tree/src/xftfont.c

diff --git a/st.c b/st.c
index e50e884..031272f 100644 (file)
--- a/st.c
+++ b/st.c
@@ -3373,16 +3373,32 @@ xgeommasktogravity(int mask)
 int
 xloadfont(Font *f, FcPattern *pattern)
 {
+       FcPattern *configured;
        FcPattern *match;
        FcResult result;
        XGlyphInfo extents;
        int wantattr, haveattr;
 
-       match = XftFontMatch(xw.dpy, xw.scr, pattern, &result);
-       if (!match)
+       /*
+        * Manually configure instead of calling XftMatchFont
+        * so that we can use the configured pattern for
+        * "missing glyph" lookups.
+        */
+       configured = FcPatternDuplicate(pattern);
+       if (!configured)
+               return 1;
+
+       FcConfigSubstitute(NULL, configured, FcMatchPattern);
+       XftDefaultSubstitute(xw.dpy, xw.scr, configured);
+
+       match = FcFontMatch(NULL, configured, &result);
+       if (!match) {
+               FcPatternDestroy(configured);
                return 1;
+       }
 
        if (!(f->match = XftFontOpenPattern(xw.dpy, match))) {
+               FcPatternDestroy(configured);
                FcPatternDestroy(match);
                return 1;
        }
@@ -3414,7 +3430,7 @@ xloadfont(Font *f, FcPattern *pattern)
                strlen(ascii_printable), &extents);
 
        f->set = NULL;
-       f->pattern = FcPatternDuplicate(pattern);
+       f->pattern = configured;
 
        f->ascent = f->match->ascent;
        f->descent = f->match->descent;