Merge pull request matplotlib#31631 from meeseeksmachine/auto-backport-of-pr-31557-on-v3.11.x

Backport PR matplotlib#31557 on branch v3.11.x (FIX: Added ft2font null checks added)

Author: QuLogic

src/ft2font.h

@@ -41,7 +41,7 @@ inline char const* ft_error_string(FT_Error error) {
 #undef __FTERRORS_H__
 #define FT_ERROR_START_LIST     switch (error) {
 #define FT_ERRORDEF( e, v, s )    case v: return s;
-#define FT_ERROR_END_LIST         default: return NULL; }
+#define FT_ERROR_END_LIST         default: return "unknown error"; }
 #include FT_ERRORS_H
 }
 

src/ft2font_wrapper.cpp

@@ -409,9 +409,9 @@ class PyFT2Font final : public FT2Font
     {
         std::set<FT_String*>::iterator it = family_names.begin();
         std::stringstream ss;
-        ss<<*it;
+        ss<< (*it ? *it : "unknown family name");
         while(++it != family_names.end()){
-            ss<<", "<<*it;
+            ss<<", "<< (*it ? *it : "unknown family name");
         }
 
         auto text_helpers = py::module_::import("matplotlib._text_helpers");