[GRASS5] 5.3 Cygwin, Tcl/Tk, NVIZ
glynn.clements at virgin.net
Mon Mar 8 15:37:23 EST 2004
Markus Neteler wrote:
> > > ==== 3/3/2004 NVWISH2.2 error message ====
> > >
> > > Error in startup script: integer value too large to represent
> > > while executing
> > > "expr int([lindex $range 0])"
> > > (procedure "mkcutplanePanel" line 55)
> > > invoked from within
> > This suggests that GS_get_zrange_nz() is returning garbage, possibly
> > because it can't find a surface.
> void GS_get_zrange_nz(float *min, float *max)
The problem is that it isn't guaranteed to write anything to *min and
*max. If they point to uninitialised variables on entry, they may
still be uninitialised upon return.
> Shouldn't it be
> int GS_get_zrange_nz(float *min, float *max)
That would only help if the caller bothers to check the return value.
> On the other hand in NVIZ there are no if statements
> so maybe a test is needed there.
There seem to be three alternative approaches:
1. Leave GS_get_zrange_nz() alone, and have the caller initialise the
variables to suitable defaults. Either GS_get_zrange_nz() will
overwrite them with other (valid) values, or they will remain
2. Change GS_get_zrange_nz() to write hardcoded defaults in the event
that it doesn't find a surface.
3. Change GS_get_zrange_nz() to return a status code, and change the
callers to handle failure.
Also, 3 could co-exist with either 1 or 2.
Glynn Clements <glynn.clements at virgin.net>
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