[GRASS5] Stars and stripes in raster maps: segfault

[Markus Neteler]

Hi,

today we discovered a severe problem in the internal raster resampling
routine. We copied a map (XY location) at lower resolution with r.mapcalc,
the result was a damaged map which crashes various modules.

See screenshots (small) are here
 http://mpa.itc.it/markus/tmp/rastercrash/

In details:

GRASS 6.1.cvs (ortoxy):~ > g.region rast="3075" -p
projection: 0 (x,y)
zone:       0
north:      1076
south:      0
west:       0
east:       1082
nsres:      1
ewres:      1
rows:       1076
cols:       1082

GRASS 6.1.cvs (ortoxy):~ > d.rast 3075
 -> screenshot "original.jpg" (see URL above)

GRASS 6.1.cvs (ortoxy):~ > g.region rast="3075" res=10

GRASS 6.1.cvs (ortoxy):~ > r.mapcalc '3075_7res="3075"'
 100%
GRASS 6.1.cvs (ortoxy):~ > d.rast 3075_7res
*** glibc detected *** free(): invalid next size (normal): 0x09067ab8 ***
Aborted
 -> screenshot "damaged_rmapcalc.jpg" see URL above)


r.out.ascii 3075_7res > /dev/null
*** glibc detected *** free(): invalid next size (normal): 0x098f6948 ***
Aborted

gdb `which r.out.ascii`
...
(gdb) bt full
#0  0x003f07a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
No symbol table info available.
#1  0x0029a7d5 in raise () from /lib/tls/libc.so.6
No symbol table info available.
#2  0x0029c149 in abort () from /lib/tls/libc.so.6
No symbol table info available.
#3  0x002ce27a in __libc_message () from /lib/tls/libc.so.6
No symbol table info available.
#4  0x002d4abf in _int_free () from /lib/tls/libc.so.6
No symbol table info available.
#5  0x002d4e3a in free () from /lib/tls/libc.so.6
No symbol table info available.
#6  0x001d7ec0 in close_old (fd=6) at closecell.c:137
        i = 8
#7  0x001d7cac in G_close_cell (fd=6) at closecell.c:82
No locals.
#8  0x08049d2f in main (argc=2, argv=0xbfe56f54) at main.c:202
        out_type = 0
        map_type = 0
        name = 0x8cebc58 "3075_7res"
        mapset = 0x8cebe90 "neteler"
        null_str = 0x804a095 "*"
        surfer_null_str = "1.70141e+038"
        fd = 6
        nrows = 108
        ncols = 108
        dp = 6
        width = 10
        rc = 0
        fp = (FILE *) 0x3985c0
        module = (struct GModule *) 0x21ddcc
        parm = {map = 0x21dd80, output = 0x8ceba70, dp = 0x8cebac0, width = 0x8cebb10, null = 0x8cebb70}
        flag = {noheader = 0x21dd60, surfer = 0x8cebbe0, modflow = 0x8cebc08, int_out = 0x8cebc30}


Using ddd I identified the crash in libgis at:
static int close_old (int fd)
...
  free (FCB.data);  <- crash

#6  0x00eddec0 in close_old (fd=7) at closecell.c:137
/hardmnt/thuille0/ssi/software/cvsgrass61/lib/gis/closecell.c:137:3931:beg:0xeddec0

which is called by G_close_cell().

Debugging the d.rast crash, it also crashes in G_close_cell().

We made a test with 6.0 where everything works smoothly. So it seems to be a
recently introduced bug. Or does it have to do with compression? Or size_t?


GRASS 6.1.cvs > pwd
/nfsmnt/mpa_gdata/ssi/BIO/GRASS_DATA/data/ortoxy/cricri/cellhd

cat 3075
proj:       0
zone:       0
north:      1076
south:      0
east:       1082
west:       0
cols:       1082
rows:       1076
e-w resol:  1
n-s resol:  1
format:     0
compressed: 2

Any suggestions?
 
 Markus