Global: fixes -ffast-math compatibility

Unifies unset double handling using `-DBL_MAX` sentinel

Fixes #1894

src/util/FFstrbuf.c

@@ -521,11 +521,11 @@ void ffStrbufPutTo(const FFstrbuf* strbuf, FILE* file)
     fputc('\n', file);
 }
 
-double ffStrbufToDouble(const FFstrbuf* strbuf)
+double ffStrbufToDouble(const FFstrbuf* strbuf, double defaultValue)
 {
     char* str_end;
     double result = strtod(strbuf->chars, &str_end);
-    return str_end == strbuf->chars ? 0.0/0.0 : result;
+    return str_end == strbuf->chars ? defaultValue : result;
 }
 
 uint64_t ffStrbufToUInt(const FFstrbuf* strbuf, uint64_t defaultValue)

src/util/FFstrbuf.h

@@ -84,7 +84,7 @@ bool ffStrbufEnsureEndsWithC(FFstrbuf* strbuf, char c);
 void ffStrbufWriteTo(const FFstrbuf* strbuf, FILE* file);
 void ffStrbufPutTo(const FFstrbuf* strbuf, FILE* file);
 
-FF_C_NODISCARD double ffStrbufToDouble(const FFstrbuf* strbuf);
+FF_C_NODISCARD double ffStrbufToDouble(const FFstrbuf* strbuf, double defaultValue);
 FF_C_NODISCARD int64_t ffStrbufToSInt(const FFstrbuf* strbuf, int64_t defaultValue);
 FF_C_NODISCARD uint64_t ffStrbufToUInt(const FFstrbuf* strbuf, uint64_t defaultValue);
 

src/util/windows/wmi.cpp

@@ -230,7 +230,7 @@ bool FFWmiRecord::getReal(const wchar_t* key, double* real)
             case VT_R4: *real = vtProp.fltVal; break;
             case VT_R8: *real = vtProp.dblVal; break;
             case VT_BOOL: *real = vtProp.boolVal != VARIANT_FALSE; break;
-            default: *real = NAN; result = false;
+            default: *real = -DBL_MAX; result = false;
         }
     }
     return result;