xdelta-1.1.3 doesn't compile with gcc 4.0.0. It fails in xdmain.c because the variable xd_handle_table is declared extern, but defined static. xd_handle_table is not used in any other file of xdelta, so changing de declaration from extern to static solves the problem. I'll attach a patch, and an ebuild that applies the patch.
Created attachment 57744 [details, diff] xdelta-1.1.3-gcc4.patch
Created attachment 57745 [details] modified ebuild
patch is fine, please find a maintainer for xdelta
Lack of any upstream development is a mild issue...
*** Bug 114917 has been marked as a duplicate of this bug. ***
While upstream might not be totally responsive, this is used in loki_patch and is updated in loki_patch's CVS. You can find their patches here: http://cvs.icculus.org/cvs/loki_patch/libs
Screw it, in cvs.