When trying the GDAL OpenJPEG driver against openjpeg current master HEAD,
I get failures when trying to create .jp2 files. The driver uses
opj_write_tile() and in some tests numresolutions = 1.
In openjp2/dwt.c:410, l_data_size = opj_dwt_max_resolution( tilec->resolutions,tilec->numresolutions) * (OPJ_UINT32)sizeof(OPJ_INT32);
is called and returns l_data_size = 0. Now in git opj_malloc() has a special case
for 0 to return a NULL pointer whereas previously it relied on system malloc(),
which in my case didn't return NULL.
So only test the pointer value if l_data_size != 0. This makes the GDAL
autotest suite to pass again.
HP compiler warns:
cc: "dwt.c", line 798: warning 562: Redeclaration of "opj_v4dwt_decode"
with a different storage class specifier: "opj_v4dwt_decode" will have
internal linkage.
cc: "t2.c", line 1341: warning 562: Redeclaration of "opj_t2_init_seg"
with a different storage class specifier: "opj_t2_init_seg" will have
internal linkage.