Linux: Fix a regression in 0.36.0 that caused font features defined via fontconfig to be ignored

Fixes #7773

docs/changelog.rst

@@ -74,6 +74,11 @@ consumption to do the same tasks.
 Detailed list of changes
 -------------------------------------
 
+0.36.1 [future]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- Linux: Fix a regression in 0.36.0 that caused font features defined via fontconfig to be ignored (:iss:`7773`)
+
 0.36.1 [2024-08-24]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

kitty/fontconfig.c

@@ -419,6 +419,9 @@ specialize_font_descriptor(PyObject *base_descriptor, double font_sz_in_pts, dou
 
     FcPattern *pat = FcPatternCreate();
     if (pat == NULL) return PyErr_NoMemory();
+    RAII_PyObject(features, PyList_New(0));
+    if (!features) return NULL;
+    RAII_PyObject(final_features, NULL);
     RAII_PyObject(ans, NULL);
     AP(FcPatternAddString, FC_FILE, (const FcChar8*)PyUnicode_AsUTF8(p), "path");
     AP(FcPatternAddInteger, FC_INDEX, face_idx, "index");
@@ -445,10 +448,23 @@ specialize_font_descriptor(PyObject *base_descriptor, double font_sz_in_pts, dou
     if (axes) {
         if (PyDict_SetItemString(ans, "axes", axes) != 0) return NULL;
     }
-    PyObject *features = PyDict_GetItemString(base_descriptor, "features");
-    if (features) {
-        if (PyDict_SetItemString(ans, "features", features) != 0) return NULL;
+    PyObject *ff = PyDict_GetItemString(ans, "fontfeatures");
+    if (ff && PyList_GET_SIZE(ff)) {
+        for (Py_ssize_t i = 0; i < PyList_GET_SIZE(ff); i++) {
+            RAII_PyObject(pff, (PyObject*)parse_font_feature(PyUnicode_AsUTF8(PyList_GET_ITEM(ff, i))));
+            if (pff == NULL) {
+                PyErr_Print(); fprintf(stderr, "\n");
+            } else if (PyList_Append(features, pff) != 0) return NULL;
+        }
     }
+    PyObject *base_features = PyDict_GetItemString(base_descriptor, "features");
+    final_features = PyTuple_New(PyList_GET_SIZE(features) + (base_features ? PyTuple_GET_SIZE(base_features) : 0));
+    if (!final_features) return NULL;
+    for (Py_ssize_t i = 0; i < PyList_GET_SIZE(features); i++) { PyTuple_SET_ITEM(final_features, i, Py_NewRef(PyList_GET_ITEM(features, i))); }
+    if (base_features) {
+        for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(base_features); i++) { PyTuple_SET_ITEM(final_features, i + PyList_GET_SIZE(features), Py_NewRef(PyTuple_GET_ITEM(base_features, i))); }
+    }
+    if (PyDict_SetItemString(ans, "features", final_features) != 0) return NULL;
     Py_INCREF(ans);
     return ans;
 end:

kitty/fonts.c

@@ -1740,18 +1740,25 @@ free_font_data(PyObject *self UNUSED, PyObject *args UNUSED) {
     Py_RETURN_NONE;
 }
 
-static PyObject *
-parsed_font_feature_new(PyTypeObject *type, PyObject *args, PyObject *kwds UNUSED) {
-    const char *s;
-    if (!PyArg_ParseTuple(args, "s", &s)) return NULL;
-    ParsedFontFeature *self = (ParsedFontFeature *)type->tp_alloc(type, 0);
+PyTypeObject ParsedFontFeature_Type;
+
+ParsedFontFeature*
+parse_font_feature(const char *spec) {
+    ParsedFontFeature *self = (ParsedFontFeature*)ParsedFontFeature_Type.tp_alloc(&ParsedFontFeature_Type, 0);
     if (self != NULL) {
-        if (!hb_feature_from_string(s, -1, &self->feature)) {
-            PyErr_Format(PyExc_ValueError, "%s is not a valid font feature", s);
+        if (!hb_feature_from_string(spec, -1, &self->feature)) {
+            PyErr_Format(PyExc_ValueError, "%s is not a valid font feature", self);
             Py_CLEAR(self);
         }
     }
-    return (PyObject*) self;
+    return self;
+}
+
+static PyObject *
+parsed_font_feature_new(PyTypeObject *type UNUSED, PyObject *args, PyObject *kwds UNUSED) {
+    const char *s;
+    if (!PyArg_ParseTuple(args, "s", &s)) return NULL;
+    return (PyObject*)parse_font_feature(s);
 }
 
 static PyObject*
@@ -1768,8 +1775,6 @@ parsed_font_feature_repr(PyObject *self_) {
 }
 
 
-PyTypeObject ParsedFontFeature_Type;
-
 static PyObject*
 parsed_font_feature_cmp(PyObject *self, PyObject *other, int op) {
     if (op != Py_EQ && op != Py_NE) return Py_NotImplemented;

kitty/fonts.h

@@ -31,6 +31,7 @@ typedef struct ParsedFontFeature {
     bool hash_computed;
 } ParsedFontFeature;
 
+ParsedFontFeature* parse_font_feature(const char *spec);
 
 // API that font backends need to implement
 unsigned int glyph_id_for_codepoint(const PyObject *, char_type);