发生了什么问题？

Upcoming changes of a frontend related to a nullable arrays initialization fails to work with 'StringBuffer reserve internal buffer' optimization

期望行为是什么？

'StringBuffer reserve internal buffer' optimization should not change string concatenation results

如何复现该缺陷

The original test which fails is static_core/plugins/ets/tests/ets_test_suite/coroutines/launch_n_workers.ets, but the code to produce the error can be reduced to this snippet:

function main(): void {
    for (let i = 0; i < 100; ++i) {
        console.log("J"+ i +"k")
    }
}

Compile the code with the patch applied.
The bytecode after manual verification, and checking with the verifier, seems right.
To get error, the runtime needs the following extra parameterization:
./build/bin/ark --boot-panda-files=./build/plugins/ets/etsstdlib.abc --compiler-enable-jit=true --no-async-jit=true --compiler-hotness-threshold=0 --load-runtimes=ets test_ets.abc ETSGLOBAL::main
The output is as follows:

"J0k"
"1k"
"2k"
"3k"
"4k"
"5k"
"6k"
"7k"
"8k"
"9k"
"10k"
"11k"
"12k"
"13k"
"14k"
"15k"
"16k"
"17k"
"18k"
"19k"
"20k"
"21k"
"22k"
"23k"
"24k"
"25k"
[TID 00d1e3] F/gc:  Broken object doesn't have class: 0x4411c0 accessed from root: STRING_TABLE
FATAL ERROR

其他补充信息

版本或分支信息

• master
• Release 4.1
• Release 4.0
• Release 3.2