Make wide flag thread-local in Utility.codeToString#502
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shared static wide bleeds between threads disassembling code, making one thread decode the next local-variable index as 2 bytes instead of 1; keep it per-thread like the adjacent CONSUMER_CHARS.
garydgregory
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garydgregory
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Jun 15, 2026
| try { | ||
| Utility.codeToString(new ByteSequence(new byte[] {(byte) Const.WIDE}), new ConstantPool(), false); | ||
| } catch (final Exception e) { | ||
| throw new AssertionError(e); |
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You could call org.junit.jupiter.api.Assertions.fail(String, Throwable) here.
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done, switched both catch blocks to fail(String, Throwable).
| // iload with a single index byte; the trailing 0x02 must stay unread. | ||
| reader.set(Utility.codeToString(new ByteSequence(new byte[] {(byte) Const.ILOAD, 1, 2}), new ConstantPool(), false)); | ||
| } catch (final Exception e) { | ||
| throw new AssertionError(e); |
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You could call org.junit.jupiter.api.Assertions.fail(String, Throwable) here.
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Jun 16, 2026
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Utility.codeToStringkeeps theWIDE-prefix state in a mutable staticboolean wide, so the flag is shared by every caller. Disassembling aWIDEopcode on one thread sets it, and a different thread decoding its next local-variable instruction (iload,istore,ret,iinc, ...) then reads a 2-byte index instead of 1 and misparses the rest of that method's code. The generic parser already avoids this by keepingwidea local inInstruction.readInstruction, and the adjacentCONSUMER_CHARSsignature-parser state in this same class was likewise moved to aThreadLocal. This does the same forwideand updates the five read/clear/set sites.Found by comparing the two
widehandlers. The addedUtilityTestregression reproduces it deterministically: aWIDEdisassembled on one thread makes aniloadon another thread decode%258instead of%1, and it fails without the change.mvn; that'smvnon the command line by itself.