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2006.10.27 19:11 "Re: TIFFReadPrivateDirectory function is not working for SUBIFD", by Sebastian Boehmer
Anurag Singh schrieb:
>
> one another important issue comes, i have made one change in
> __TIFFReadCustomDirectoryPart for our own purpose to read subifd,
> it's very true that at the time of reading any SubIFD , there's no one
> tag is registered, because we are passing these parameters
> tif->tif_nPrivateFields, tif->tif_privateFieldInfo, which are
> initially NULL.
ok that's no prob. In a first call of
__TIFFMergeFieldInfo(&tif->tif_nPrivateFields,&tif->tif_privateFieldInfo,n,info,1)
is tif_nPrivateFields=0 and tif_privateFieldInfo=NULL, but n is not zero
and info is not NULL.
If info=NULL and n not zero there was a wrong call of the function
TIFFMergePrivateFieldInfo.
n should be the size of the new to merged info.
>
> So each n very time tag goes to merge by using
> TIFFMergePrivateFieldInfo() and in turn this function make call
> __TIFFMergeFieldInfo(&tif->tif_nPrivateFields,&tif->tif_privateFieldInfo,n,info,1)
> , after merging 2-3 times , i got HEAP error in this funtion, and
> reason of it, mergedIndices is currupted.
> i want explain it, we are merging one tag each n every time, so here
> n=1 and info have one tag only.
You mean you call the TIFFMergedPrivateFieldInfo n times with the same tag?
The sorted array tif->tif_privateFieldInfo contains only tags with
unique tag numbers!
For this reason we check in the loop you quoted below if info contains a
new tag.
>
> I think problem is here. this is the code of function
> __TIFFMergeFieldInfo
>
Sorry I don't realy understand your problem. Perhapse could you explain
it for me in a private e-mail.
--
greets
>
> if
>
> ( support ) {
>
> mergedIndices = _TIFFmalloc(n*
>
> sizeof(int));
>
> }
>
> if (*nfields > 0) {
> if ( support ) {
>
> /*
>
> * Merge only not already existing tags. Asume unsorted TIFFFieldInfo
> array.
>
> */
>
> for (fi=0; fi < *nfields; ++fi) { for (i =0; i < n; ++i)
> if (info_new[i].field_tag == (*info)[fi]->field_tag) break;
> if ( i >= n ) { // entry not found
>
> mergedIndices[nn] = i;
>
> // remember index
>
> ++nn;
>
> }
>
> }
>
> if ( nn == 0 ) goto end; // no new entries;
>
> n = nn;
>
> }
>
>
> we are allocationg memory to mergedIndices of size n, mean in the
> SubIFD's case 1 and adding more than value, here is some logical error
> for tha case when only one tag is merged in a group.
>
> Please have a look on this problem.
>
> Anurag
>
>
>
>
> ------------------------------------------------------------------------
>
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