From 8d03d7216f77b4dc5069f7aebe22ee9d0cc4c30e Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 29 Sep 2017 11:57:17 +0530
Subject: [PATCH] Do not crash when failing to render a glyph, instead render
 the missing glyph and print an error msg to stderr

---
 kitty/fonts/freetype.py |  5 ++++-
 kitty/freetype.c        | 12 ++++++++----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/kitty/fonts/freetype.py b/kitty/fonts/freetype.py
index 2f3051855..e61ba6f3b 100644
--- a/kitty/fonts/freetype.py
+++ b/kitty/fonts/freetype.py
@@ -8,7 +8,7 @@ from collections import namedtuple
 from functools import lru_cache
 from itertools import chain
 
-from kitty.fast_data_types import FT_PIXEL_MODE_GRAY, Face
+from kitty.fast_data_types import FT_PIXEL_MODE_GRAY, Face, FreeTypeError
 from kitty.fonts.box_drawing import render_missing_glyph
 from kitty.utils import ceil_int, get_logical_dpi, safe_print, wcwidth, adjust_line_height
 
@@ -258,6 +258,9 @@ def render_cell(text=' ', bold=False, italic=False):
     except FontNotFound as err:
         safe_print('ERROR:', err, file=sys.stderr)
         return missing_glyph(width)
+    except FreeTypeError as err:
+        safe_print('Failed to render text:', repr(text), 'with error:', err, file=sys.stderr)
+        return missing_glyph(width)
     second = None
     if width == 2:
         if bitmap_char.columns > cell_width:
diff --git a/kitty/freetype.c b/kitty/freetype.c
index 6cb918310..d6a7bc7c8 100644
--- a/kitty/freetype.c
+++ b/kitty/freetype.c
@@ -18,6 +18,7 @@ typedef struct {
     bool is_scalable;
 } Face;
 
+static PyObject* FreeType_Exception = NULL;
 
 void 
 set_freetype_error(const char* prefix, int err_code) {
@@ -41,12 +42,12 @@ set_freetype_error(const char* prefix, int err_code) {
 
     while(ft_errors[i].err_msg != NULL) {
         if (ft_errors[i].err_code == err_code) {
-            PyErr_Format(PyExc_ValueError, "%s %s", prefix, ft_errors[i].err_msg);
+            PyErr_Format(FreeType_Exception, "%s %s", prefix, ft_errors[i].err_msg);
             return;
         }
         i++;
     }
-    PyErr_Format(PyExc_ValueError, "%s (error code: %d)", prefix, err_code);
+    PyErr_Format(FreeType_Exception, "%s (error code: %d)", prefix, err_code);
 }
 
 static FT_Library  library;
@@ -190,7 +191,7 @@ trim_to_width(Face UNUSED *self, PyObject *args) {
     rows = PyLong_AsUnsignedLong(PyStructSequence_GET_ITEM(bitmap, 0));
     width = PyLong_AsUnsignedLong(PyStructSequence_GET_ITEM(bitmap, 1));
     extra = width - cell_width;
-    if (extra >= cell_width) { PyErr_SetString(PyExc_ValueError, "Too large for trimming"); return NULL; }
+    if (extra >= cell_width) { PyErr_SetString(FreeType_Exception, "Too large for trimming"); return NULL; }
     PyObject *ans = PyStructSequence_New(&BitmapType);
     if (ans == NULL) return PyErr_NoMemory();
     src = (unsigned char*)PyByteArray_AS_STRING(PyStructSequence_GET_ITEM(bitmap, 3));
@@ -267,13 +268,16 @@ free_freetype() {
 
 bool 
 init_freetype_library(PyObject *m) {
+    FreeType_Exception = PyErr_NewException("fast_data_types.FreeTypeError", NULL, NULL);
+    if (FreeType_Exception == NULL) return false;
+    if (PyModule_AddObject(m, "FreeTypeError", FreeType_Exception) != 0) return false;
     int error = FT_Init_FreeType(&library);
     if (error) {
         set_freetype_error("Failed to initialize FreeType library, with error:", error);
         return false;
     }
     if (Py_AtExit(free_freetype) != 0) {
-        PyErr_SetString(PyExc_RuntimeError, "Failed to register the freetype library at exit handler");
+        PyErr_SetString(FreeType_Exception, "Failed to register the freetype library at exit handler");
         return false;
     }
     if (PyStructSequence_InitType2(&GlpyhMetricsType, &gm_desc) != 0) return false;