Reject font values that are invalid for pango

Use pango to parse font configuration early, and reject the command as
invalid if the value is invalid for pango. Since we're already parsing
the font into a `PangoFontDescription`, keep that instance around and
avoid re-parsing the font each time we render text.

Fixes: https://github.com/swaywm/sway/issues/6805

1 files changed, 1 insertions, 3 deletions

diff --git a/common/pango.c b/common/pango.c
index abc18281..e8e2678d 100644
--- a/common/pango.c
+++ b/common/pango.c
@@ -109,10 +109,9 @@ void get_text_size(cairo_t *cairo, const char *font, int *width, int *height,
         free(buf);
 }
 
-void get_text_metrics(const char *font, int *height, int *baseline) {
+void get_text_metrics(const PangoFontDescription *description, int *height, int *baseline) {
         cairo_t *cairo = cairo_create(NULL);
         PangoContext *pango = pango_cairo_create_context(cairo);
-        PangoFontDescription *description = pango_font_description_from_string(font);
         // When passing NULL as a language, pango uses the current locale.
         PangoFontMetrics *metrics = pango_context_get_metrics(pango, description, NULL);
 
@@ -120,7 +119,6 @@ void get_text_metrics(const char *font, int *height, int *baseline) {
         *height = *baseline + pango_font_metrics_get_descent(metrics) / PANGO_SCALE;
 
         pango_font_metrics_unref(metrics);
-        pango_font_description_free(description);
         g_object_unref(pango);
         cairo_destroy(cairo);
 }