On Mon, 2012-03-26 at 11:14 +0200, Andoni Morales wrote:
> -    case MSIMODIFY_REPLACE:
>      case MSIMODIFY_MERGE:
> +      /* check for a duplicated key */
> +      r = msi_table_find_row( tv, rec, &row, column );
> +      if (r == ERROR_SUCCESS) {
> +        /* check that both are identical */
> +        r = compare_record (tv, row, rec);
> +        if (r != ERROR_SUCCESS)
> +          break;
> +      } else {
> +        r = table_validate_new( tv, rec, NULL );
> +        if (r != ERROR_SUCCESS)
> +          break;
> +        r = TABLE_insert_row( view, rec, -1, FALSE );
> +          break;
> +      }
> +
> +    case MSIMODIFY_REPLACE:

Please use bracketing and indentation style of the surrounding code.
Some tests would be nice.