trydiff: make variable names more consistent
Use '1' and '2' as suffix for names just like in the parameters
'ctx[12]':
to,tn -> content1,content2
a,b -> f1, f2
omode,mode -> mode1,mode2
omode,nmode -> mode1,mode2
onode,nnode -> node1,node2
oflag,nflag -> flag1,flag2
oindex,nindex -> index1,index2
(binary:application/octet-stream)