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);

mysql-test/r/insert.result

@@ -169,7 +169,6 @@ set @value= "1e+1111111111a";
 insert into t1 values(null,@value,@value,@value,@value,@value,@value,@value,@value,@value);
 Warnings:
 Warning	1265	Data truncated for column 'f_double        ' at row 1
-Warning	1264	Data truncated, out of range for column 'f_double        ' at row 1
 Warning	1265	Data truncated for column 'f_float         ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float         ' at row 1
 Warning	1265	Data truncated for column 'f_double_7_2    ' at row 1
@@ -177,7 +176,6 @@ Warning	1264	Data truncated, out of range for column 'f_double_7_2    ' at row 1
 Warning	1265	Data truncated for column 'f_float_4_3     ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float_4_3     ' at row 1
 Warning	1265	Data truncated for column 'f_double_u      ' at row 1
-Warning	1264	Data truncated, out of range for column 'f_double_u      ' at row 1
 Warning	1265	Data truncated for column 'f_float_u       ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float_u       ' at row 1
 Warning	1265	Data truncated for column 'f_double_15_1_u ' at row 1
@@ -199,7 +197,6 @@ set @value= "-1e+1111111111a";
 insert into t1 values(null,@value,@value,@value,@value,@value,@value,@value,@value,@value);
 Warnings:
 Warning	1265	Data truncated for column 'f_double        ' at row 1
-Warning	1264	Data truncated, out of range for column 'f_double        ' at row 1
 Warning	1265	Data truncated for column 'f_float         ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float         ' at row 1
 Warning	1265	Data truncated for column 'f_double_7_2    ' at row 1
@@ -228,17 +225,15 @@ f_float_3_1_u   	0.0
 set @value= 1e+1111111111;
 insert into t1 values(null,@value,@value,@value,@value,@value,@value,@value,@value,@value);
 Warnings:
-Warning	1264	Data truncated, out of range for column 'f_double        ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float         ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_double_7_2    ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float_4_3     ' at row 1
-Warning	1264	Data truncated, out of range for column 'f_double_u      ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float_u       ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_double_15_1_u ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float_3_1_u   ' at row 1
 select * from t1 where `number          `=last_insert_id();
 number          	6
-original_value  	inf
+original_value  	1.7976931348623e+308
 f_double        	1.79769313486232e+308
 f_float         	3.40282e+38
 f_double_7_2    	99999.99
@@ -250,7 +245,6 @@ f_float_3_1_u   	99.9
 set @value= -1e+1111111111;
 insert into t1 values(null,@value,@value,@value,@value,@value,@value,@value,@value,@value);
 Warnings:
-Warning	1264	Data truncated, out of range for column 'f_double        ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float         ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_double_7_2    ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float_4_3     ' at row 1
@@ -260,7 +254,7 @@ Warning	1264	Data truncated, out of range for column 'f_double_15_1_u ' at row 1
 Warning	1264	Data truncated, out of range for column 'f_float_3_1_u   ' at row 1
 select * from t1 where `number          `=last_insert_id();
 number          	7
-original_value  	-inf
+original_value  	-1.7976931348623e+308
 f_double        	-1.79769313486232e+308
 f_float         	-3.40282e+38
 f_double_7_2    	-99999.99

mysql-test/r/mysqldump.result

@@ -46,8 +46,6 @@ UNLOCK TABLES;
 DROP TABLE t1;
 CREATE TABLE t1 (a double);
 INSERT INTO t1 VALUES (-9e999999);
-Warnings:
-Warning	1264	Data truncated, out of range for column 'a' at row 1
 
 /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT, CHARACTER_SET_CLIENT=utf8 */;
 /*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;

strings/strtod.c

@@ -2,7 +2,7 @@
   An alternative implementation of "strtod()" that is both
   simplier, and thread-safe.
 
-  From mit-threads as bundled with MySQL 3.22
+  From mit-threads as bundled with MySQL 3.23
 
   SQL:2003 specifies a number as
 
@@ -41,6 +41,7 @@ double my_strtod(const char *str, char **end)
   double result= 0.0;
   int negative, ndigits;
   const char *old_str;
+  my_bool overflow=0;
 
   while (my_isspace(&my_charset_latin1, *str))
     str++;
@@ -85,6 +86,7 @@ double my_strtod(const char *str, char **end)
       double scaler= 1.0;
       while (my_isdigit (&my_charset_latin1, *str))
       {
+        if (exp < 9999) /* protection against exp overflow */
           exp= exp*10 + *str - '0';
         str++;
       }
@@ -93,7 +95,7 @@ double my_strtod(const char *str, char **end)
         if (neg)
           result= 0.0;
         else
-          result= DBL_MAX*10;
+          overflow=1;
         goto done;
       }
       while (exp >= 100)
@@ -113,6 +115,12 @@ done:
   if (end)
     *end = (char *)str;
 
+  if (overflow || ((overflow=isinf(result))))
+  {
+    result=DBL_MAX;
+    errno=EOVERFLOW;
+  }
+
   return negative ? -result : result;
 }