  pcf_get_metric( FT_Stream   stream,
                  FT_ULong    format,
                  PCF_Metric  metric )
  {
    FT_Error  error = FT_Err_Ok;


    if ( PCF_FORMAT_MATCH( format, PCF_DEFAULT_FORMAT ) )
    {
      const FT_Frame_Field*  fields;


      /* parsing normal metrics */
      fields = PCF_BYTE_ORDER( format ) == MSBFirst
               ? pcf_metric_msb_header
               : pcf_metric_header;

      /* the following sets `error' but doesn't return in case of failure */
      (void)FT_STREAM_READ_FIELDS( fields, metric );
    }
    else
    {
      PCF_Compressed_MetricRec  compr;


      /* parsing compressed metrics */
      if ( FT_STREAM_READ_FIELDS( pcf_compressed_metric_header, &compr ) )
        goto Exit;

      metric->leftSideBearing  = (FT_Short)( compr.leftSideBearing  - 0x80 );
      metric->rightSideBearing = (FT_Short)( compr.rightSideBearing - 0x80 );
      metric->characterWidth   = (FT_Short)( compr.characterWidth   - 0x80 );
      metric->ascent           = (FT_Short)( compr.ascent           - 0x80 );
      metric->descent          = (FT_Short)( compr.descent          - 0x80 );
      metric->attributes       = 0;
    }

  Exit:
    return error;
  }

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.