crash #3 reading shape file

[simon@…]

in the file /ogr/ogrsf_frmts/shape/dbfopen.c
we traced a crash to the following function.  We put a null check on
pszValue after the DBFReadStringAttribute call and it bypassed the problem.


int SHPAPI_CALL
DBFIsAttributeNULL( DBFHandle psDBF, int iRecord, int iField )

{   
    const char	*pszValue = NULL;

	  	
    pszValue = DBFReadStringAttribute( psDBF, iRecord, iField );

		// SPR Petroys NULL Check added
    if (pszValue == NULL)
       return 1;

    switch(psDBF->pachFieldType[iField])
    {
      case 'N':
      case 'F':
        /* NULL numeric fields have value "****************" */
        return pszValue[0] == '*';

      case 'D':
        /* NULL date fields have value "00000000" */
        return strncmp(pszValue,"00000000",8) == 0;

      case 'L':
        /* NULL boolean fields have value "?" */ 
        return pszValue[0] == '?';

      default:
        /* empty string fields are considered NULL */
        return strlen(pszValue) == 0;
    }
}

[warmerdam]

This appears to be a repeat of #360. 


*** This bug has been marked as a duplicate of 360 ***

[warmerdam]

This isn't exactly a dup of 360; since 360 refers to frmts/shapelib/shpopen.c, 
and this one to the OGR copy.  However, after updates to the master (shapelib/*)
I copy the code to the ogr driver directory so the update is in both places.