Possible access to unintended variable in "icu-ios/icu/source/common/utrie2_builder.cpp" line 1046

[petrufm]

While experimenting with a CodeSonar plugin we develop, we noticed a potential bug in file "icu-ios/icu/source/common/utrie2_builder.cpp" line 1046 function compactData:

movedStart=newStart-overlap;
for(i=blockCount, mapIndex=start>>UTRIE2_SHIFT_2; i>0; --i) { //HERE
trie->map[mapIndex++]=movedStart;
movedStart+=UTRIE2_DATA_BLOCK_LENGTH;
}

Shouldn't movedStart be used to initialise mapIndex at the start of the loop instead of start? Similarly in line 1025. We are not very sure about this one due to our limited understanding of the code. However, we would be happy to get a deeper understanding here even if we are wrong :).

Thanks,
Petru Florin Mihancea