Commit 6311217a authored by unknown's avatar unknown
Browse files

Fix modify_defaults_file as agreed with monty (correct all occurences of an option in the section) 


mysys/default_modify.c:
  Correct all occurences of an option in the section. To avoid memory problems preallocate reserve of 1K, and
  realloc it later if needed (almost never).
parent cceab6e6

mysys/default_modify.c

+41 −16
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 
#include <my_dir.h>



#define BUFF_SIZE 1024

/* should be big enough to handle at least one line */

#define RESERVE 1024



#ifdef __WIN__

#define NEWLINE "\r\n"
@@ -66,8 +68,10 @@ int modify_defaults_file(const char *file_location, const char *option, 
  FILE *cnf_file;

  MY_STAT file_stat;

  char linebuff[BUFF_SIZE], *src_ptr, *dst_ptr, *file_buffer;

  uint opt_len, optval_len, sect_len, nr_newlines= 0;

  uint opt_len, optval_len, sect_len, nr_newlines= 0, buffer_size;

  my_bool in_section= FALSE, opt_applied= 0;

  int reserve_occupied= 0, reserve_extended= 1, old_opt_len;

  int new_opt_len= opt_len + 1 + optval_len + NEWLINE_LEN;

  DBUG_ENTER("modify_defaults_file");



  if (!(cnf_file= my_fopen(file_location, O_RDWR | O_BINARY, MYF(0))))
@@ -80,23 +84,26 @@ int modify_defaults_file(const char *file_location, const char *option, 
  opt_len= (uint) strlen(option);

  optval_len= (uint) strlen(option_value);



  /*

    Reserve space to read the contents of the file and some more

    for the option we want to add.

  */

  if (!(file_buffer= (char*) my_malloc(sizeof(char) *

                                       (file_stat.st_size +

  /* calculate the size of the buffer we need */

  buffer_size= sizeof(char) * (file_stat.st_size +

                               /* option name len */

                               opt_len +

                                        /* reserve space for newline */

                                        NEWLINE_LEN +

                               /* reserve for '=' char */

                               1 +

                               /* option value len */

                               optval_len +

                               /* reserve space for newline */

                               NEWLINE_LEN +

                               /* The ending zero */

                                        1), MYF(MY_WME))))

                               1 +

                               /* reserve some additional space */

                               RESERVE);



  /*

    Reserve space to read the contents of the file and some more

    for the option we want to add.

  */

  if (!(file_buffer= (char*) my_malloc(buffer_size, MYF(MY_WME))))

    goto malloc_err;



  sect_len= (uint) strlen(section_name);
@@ -115,13 +122,31 @@ int modify_defaults_file(const char *file_location, const char *option, 
    }



    /* correct the option */

    if (!opt_applied && in_section && !strncmp(src_ptr, option, opt_len) &&

    if (in_section && !strncmp(src_ptr, option, opt_len) &&

        (*(src_ptr + opt_len) == '=' ||

         my_isspace(&my_charset_latin1, *(src_ptr + opt_len)) ||

         *(src_ptr + opt_len) == '\0'))

    {

      dst_ptr= add_option(dst_ptr, option_value, option, remove_option);

      /*

        we should change all options. If opt_applied is set, we are running

        into reserved memory area. Hence we should check for overruns.

      */

      if (opt_applied)

      {

        old_opt_len= strlen(linebuff);

        /* could be negative */

        reserve_occupied+= new_opt_len - old_opt_len;

        if (reserve_occupied > RESERVE*reserve_extended)

        {

          file_buffer= (char*) my_realloc(file_buffer, buffer_size +

                                          RESERVE*reserve_extended,

                                          MYF(MY_WME));

          reserve_extended++;

        }

      }

      else

        opt_applied= 1;

      dst_ptr= add_option(dst_ptr, option_value, option, remove_option);

    }

    else

    {