Removed Static_binary_string

This did not server any real purpose and also made it too difficult to add
asserts for string memory overrwrites.

Moved all functionallity from Static_binary_string to Binary_string.

Other things:
- Added asserts to q_xxx and qs_xxx functions to check for memory overruns
- Fixed wrong test in String_buffer::set_buffer_if_not_allocated().
  The idea is to reuse allocated buffers (to avoid extra allocs), which
  the code did not do.

Author: montywi

sql/sql_string.cc

@@ -163,8 +163,9 @@ static inline void APPEND_HEX(char *&to, uchar value)
 }
 
 
-void Static_binary_string::qs_append_hex(const char *str, uint32 len)
+void Binary_string::qs_append_hex(const char *str, uint32 len)
 {
+  ASSERT_LENGTH(len*2);
   const char *str_end= str + len;
   for (char *to= Ptr + str_length ; str < str_end; str++)
     APPEND_HEX(to, (uchar) *str);
@@ -665,7 +666,7 @@ bool String::append_with_prefill(const char *s,uint32 arg_length,
 }
 
 
-int Static_binary_string::strstr(const Static_binary_string &s, uint32 offset)
+int Binary_string::strstr(const Binary_string &s, uint32 offset)
 {
   if (s.length()+offset <= str_length)
   {
@@ -696,7 +697,7 @@ int Static_binary_string::strstr(const Static_binary_string &s, uint32 offset)
 ** Search string from end. Offset is offset to the end of string
 */
 
-int Static_binary_string::strrstr(const Static_binary_string &s, uint32 offset)
+int Binary_string::strrstr(const Binary_string &s, uint32 offset)
 {
   if (s.length() <= offset && offset <= str_length)
   {
@@ -766,38 +767,43 @@ int Binary_string::reserve(size_t space_needed, size_t grow_by)
   return FALSE;
 }
 
-void Static_binary_string::qs_append(const char *str, size_t len)
+void Binary_string::qs_append(const char *str, size_t len)
 {
+  ASSERT_LENGTH(len);
   memcpy(Ptr + str_length, str, len + 1);
   str_length += (uint32)len;
 }
 
-void Static_binary_string::qs_append(double d)
+void Binary_string::qs_append(double d)
 {
   char *buff = Ptr + str_length;
-  str_length+= (uint32) my_gcvt(d, MY_GCVT_ARG_DOUBLE, FLOATING_POINT_BUFFER - 1, buff,
-                       NULL);
+  size_t length= my_gcvt(d, MY_GCVT_ARG_DOUBLE, FLOATING_POINT_BUFFER - 1,
+                         buff, NULL);
+  ASSERT_LENGTH(length);
+  str_length+= (uint32) length;
 }
 
-void Static_binary_string::qs_append(const double *d)
+void Binary_string::qs_append(const double *d)
 {
   double ld;
   float8get(ld, (const char*) d);
   qs_append(ld);
 }
 
-void Static_binary_string::qs_append(int i)
+void Binary_string::qs_append(int i)
 {
   char *buff= Ptr + str_length;
   char *end= int10_to_str(i, buff, -10);
-  str_length+= (int) (end-buff);
+  ASSERT_LENGTH((size_t) (end-buff));
+  str_length+= (uint32) (end-buff);
 }
 
-void Static_binary_string::qs_append(ulonglong i)
+void Binary_string::qs_append(ulonglong i)
 {
   char *buff= Ptr + str_length;
   char *end= longlong10_to_str(i, buff, 10);
-  str_length+= (int) (end-buff);
+  ASSERT_LENGTH((size_t) (end-buff));
+  str_length+= (uint32) (end-buff);
 }