[GRASSLIST:9841] r.mapcalc causing segmentation violation

[Ralf Gerlich]

Hi,

I'm trying to do a shaded relief map using r.shaded.relief and always
get a segmentation violation when r.mapcalc is called.

With today's CVS version I get the following backtrace:

=========================================================================

GRASS 6.1.cvs (utm):~/misc/gis > gdb r.mapcalc
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This GDB was configured as "i486-linux-gnu"...Using host libthread_db
library "/ lib/tls/libthread_db.so.1".

(gdb) run OUT=elev[0,-1]
Starting program:
/home/ralfg/misc/gis/src/grass-6.1.0/dist.i486-pc-linux-gnu/bi
n/r.mapcalc OUT=elev[0,-1]
    0%
Program received signal SIGSEGV, Segmentation fault.
0xb7f63ca3 in G__convert_flags_01 (zero_ones=0x80851f0 "\001\001\001",
     flags=0x0, n=5738) at null_val.c:790
790                     zero_ones[count] = ((*v & ( (unsigned char) 1 <<
k)) != 0);
(gdb) bt
#0  0xb7f63ca3 in G__convert_flags_01 (zero_ones=0x80851f0 "\001\001\001",
     flags=0x0, n=5738) at null_val.c:790
#1  0xb7f5cd7d in get_null_value_row (fd=0, flags=0x80851f0 "\001\001\001",
     row=1, with_mask=1) at get_row.c:1021
#2  0xb7f5d35a in get_map_row (fd=0, rast=0x805f360, row=1, data_type=1,
     null_is_zero=0, with_mask=1) at get_row.c:1067
#3  0x08055b9d in read_row (fd=0, buf=0x805f360 "", row=1, dummy=0)
     at map.c:227
#4  0x08055ccd in read_map (m=<value optimized out>, buf=0x805f360,
     res_type=1, row=0, col=-1) at map.c:295
#5  0x08056620 in get_map_row (idx=0, mod=77, depth=0, row=1, col=-1,
     buf=0x805f360, res_type=7) at map.c:465
#6  0x0804e7a5 in evaluate (e=0x805f300) at evaluate.c:123
#7  0x0804eaec in execute (ee=0x805b170) at evaluate.c:260
#8  0x0804ffc2 in main (argc=2, argv=0xbfaeebe4) at main.c:128
(gdb)

=========================================================================

Note that this happens with "OUT=elev[0,-1]" and any other reference to
negative column numbers, but not with non-negative column numbers.

It seems as if the null-rows in the file-control-block are not initialised.

Any ideas? I'm ready to follow any pointers you give me.

Best regards,
Ralf Gerlich