Use builtin NERD font for symbol_map if no system NERD font is available

kitty/core_text.m

@@ -640,7 +640,18 @@ cell_metrics(PyObject *s, unsigned int* cell_width, unsigned int* cell_height, u
 
 PyObject*
 face_from_descriptor(PyObject *descriptor, FONTS_DATA_HANDLE fg) {
-    RAII_CoreFoundation(CTFontDescriptorRef, desc, font_descriptor_from_python(descriptor));
+    RAII_CoreFoundation(CTFontDescriptorRef, desc, NULL);
+    if (builtin_nerd_font_descriptor) {
+        PyObject *psname = PyDict_GetItemString(descriptor, "postscript_name");
+        if (psname && PyUnicode_CompareWithASCIIString(psname, "SymbolsNFM") == 0) {
+            RAII_PyObject(path, get_path_for_font_descriptor(builtin_nerd_font_descriptor));
+            PyObject *dpath = PyDict_GetItemString(descriptor, "path");
+            if (dpath && PyUnicode_Compare(path, dpath) == 0) {
+                desc = builtin_nerd_font_descriptor; CFRetain(desc);
+            }
+        }
+    }
+    if (!desc) desc = font_descriptor_from_python(descriptor);
     if (!desc) return NULL;
     RAII_CoreFoundation(CTFontRef, font, CTFontCreateWithFontDescriptor(desc, fg ? scaled_point_sz(fg) : 12, NULL));
     if (!font) { PyErr_SetString(PyExc_ValueError, "Failed to create CTFont object"); return NULL; }
@@ -672,8 +683,7 @@ new(PyTypeObject *type UNUSED, PyObject *args, PyObject *kw) {
 
 PyObject*
 specialize_font_descriptor(PyObject *base_descriptor, double font_sz_in_pts UNUSED, double dpi_x UNUSED, double dpi_y UNUSED) {
-    Py_INCREF(base_descriptor);
-    return base_descriptor;
+    return PyDict_Copy(base_descriptor);
 }
 
 struct RenderBuffers {
@@ -1135,7 +1145,7 @@ set_builtin_nerd_font(PyObject UNUSED *self, PyObject *pypath) {
     if (builtin_nerd_font_descriptor) CFRelease(builtin_nerd_font_descriptor);
     builtin_nerd_font_descriptor = CFArrayGetValueAtIndex(descriptors, 0);
     CFRetain(builtin_nerd_font_descriptor);
-    Py_RETURN_NONE;
+    return font_descriptor_to_python(builtin_nerd_font_descriptor);
 }
 
 static PyMethodDef module_methods[] = {

kitty/fast_data_types.pyi

@@ -426,7 +426,7 @@ def fc_match_postscript_name(
 
 
 def add_font_file(path: str) -> bool: ...
-def set_builtin_nerd_font(path: str) -> None: ...
+def set_builtin_nerd_font(path: str) -> Union[CoreTextFont, FontConfigPattern]: ...
 
 
 class FeatureData(TypedDict):

kitty/fontconfig.c

@@ -426,6 +426,12 @@ specialize_font_descriptor(PyObject *base_descriptor, double font_sz_in_pts, dou
     AP(FcPatternAddDouble, FC_DPI, (dpi_x + dpi_y) / 2.0, "dpi");
     ans = _fc_match(pat);
     FcPatternDestroy(pat); pat = NULL;
+    if (!ans) return NULL;
+    // fontconfig returns a completely random font if the base descriptor
+    // points to a font that fontconfig hasnt indexed, for example the builting
+    // NERD font
+    PyObject *new_path = PyDict_GetItemString(ans, "path");
+    if (!new_path || PyObject_RichCompareBool(p, new_path, Py_EQ) != 1) { Py_CLEAR(ans); ans = PyDict_Copy(base_descriptor); if (!ans) return NULL;  }
 
     if (face_idx > 0) {
         // For some reason FcFontMatch sets the index to zero, so manually restore it.
@@ -538,6 +544,7 @@ set_builtin_nerd_font(PyObject UNUSED *self, PyObject *pypath) {
         copy(hinting); copy(hint_style);
 #undef copy
         if (PyDict_SetItemString(builtin_nerd_font.descriptor, "path", pypath) != 0) goto end;
+        if (PyDict_SetItemString(builtin_nerd_font.descriptor, "index", PyLong_FromLong(0)) != 0) goto end;
     }
 end:
     if (pat) FcPatternDestroy(pat);
@@ -546,7 +553,8 @@ end:
         Py_CLEAR(builtin_nerd_font.descriptor);
         return NULL;
     }
-    Py_RETURN_NONE;
+    Py_INCREF(builtin_nerd_font.descriptor);
+    return builtin_nerd_font.descriptor;
 }
 
 

kitty/fonts/render.py

@@ -31,6 +31,7 @@ from kitty.types import _T
 from kitty.typing import CoreTextFont, FontConfigPattern
 from kitty.utils import log_error
 
+from . import family_name_to_key
 from .common import get_font_files
 
 if is_macos:
@@ -40,6 +41,7 @@ else:
 
 FontObject = Union[CoreTextFont, FontConfigPattern]
 current_faces: List[Tuple[FontObject, bool, bool]] = []
+builtin_nerd_font_descriptor: Optional[FontObject] = None
 
 
 def font_for_family(family: str) -> Tuple[FontObject, bool, bool]:
@@ -145,6 +147,10 @@ def create_symbol_map(opts: Options) -> Tuple[Tuple[int, int, int], ...]:
     for family in val.values():
         if family not in family_map:
             font, bold, italic = font_for_family(family)
+            fkey = family_name_to_key(family)
+            if fkey in ('symbolsnfm', 'symbols nerd font mono') and font['postscript_name'] != 'SymbolsNFM' and builtin_nerd_font_descriptor:
+                font = builtin_nerd_font_descriptor
+                bold = italic = False
             family_map[family] = count
             count += 1
             current_faces.append((font, bold, italic))
@@ -172,8 +178,8 @@ def dump_font_debug() -> None:
             log_error('  ' + s.identify_for_debug())
 
 
-def set_font_family(opts: Optional[Options] = None, override_font_size: Optional[float] = None) -> None:
-    global current_faces
+def set_font_family(opts: Optional[Options] = None, override_font_size: Optional[float] = None, add_builtin_nerd_font: bool = False) -> None:
+    global current_faces, builtin_nerd_font_descriptor
     opts = opts or defaults
     sz = override_font_size or opts.font_size
     font_map = get_font_files(opts)
@@ -185,6 +191,12 @@ def set_font_family(opts: Optional[Options] = None, override_font_size: Optional
             indices[k] = len(current_faces)
             current_faces.append((font_map[k], 'b' in k, 'i' in k))
     before = len(current_faces)
+    if add_builtin_nerd_font:
+        builtin_nerd_font_path = os.path.join(fonts_dir, 'SymbolsNerdFontMono-Regular.ttf')
+        if os.path.exists(builtin_nerd_font_path):
+            builtin_nerd_font_descriptor = set_builtin_nerd_font(builtin_nerd_font_path)
+        else:
+            log_error(f'No builtin NERD font found in {fonts_dir}')
     sm = create_symbol_map(opts)
     ns = create_narrow_symbols(opts)
     num_symbol_fonts = len(current_faces) - before
@@ -195,15 +207,6 @@ def set_font_family(opts: Optional[Options] = None, override_font_size: Optional
     )
 
 
-def add_application_fonts() -> None:
-    for font in ('SymbolsNerdFontMono-Regular.ttf',):
-        path = os.path.join(fonts_dir, font)
-        if os.path.exists(path):
-            set_builtin_nerd_font(path)
-        else:
-            log_error(f'No builtin NERD font found in {fonts_dir}')
-
-
 if TYPE_CHECKING:
     CBufType = ctypes.Array[ctypes.c_ubyte]
 else:

kitty/main.py

@@ -44,7 +44,7 @@ from .fast_data_types import (
     set_options,
 )
 from .fonts.box_drawing import set_scale
-from .fonts.render import add_application_fonts, dump_font_debug, set_font_family
+from .fonts.render import dump_font_debug, set_font_family
 from .options.types import Options
 from .options.utils import DELETE_ENV_VAR
 from .os_window_size import edge_spacing, initial_window_size_func
@@ -248,8 +248,7 @@ class AppRunner:
         set_scale(opts.box_drawing_scale)
         set_options(opts, is_wayland(), args.debug_rendering, args.debug_font_fallback)
         try:
-            set_font_family(opts)
-            add_application_fonts()
+            set_font_family(opts, add_builtin_nerd_font=True)
             _run_app(opts, args, bad_lines, talk_fd)
         finally:
             set_options(None)