my_strtod fixes:

sigsegv protection (exp overflow)
don't return inf!
use errno=EOVERFLOW to signal an overflow (as my_strntod uses errno anyway)
if errno will be too slow, my_strtod can be changed to return overflow status in a parameter (like my_strntod does)

include/m_string.h

@@ -218,6 +218,9 @@ extern int is_prefix(const char *, const char *);
 /* Conversion routines */
 double my_strtod(const char *str, char **end);
 double my_atof(const char *nptr);
+#ifndef EOVERFLOW
+#define EOVERFLOW 84
+#endif
 
 #ifdef USE_MY_ITOA
 extern char *my_itoa(int val,char *dst,int radix);