MDEV-38670 Unary minus on empty string returns -0 #4632
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gkodinov
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Normalize -0.0 to +0.0 in Item_func_neg::real_op() to match binary subtraction behavior. Add test case in type_newdecimal. add result for tests fix tests Revert whitespace changes in type_newdecimal.result Revert whitespace changes in type_newdecimal.test
ParadoxV5
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Feb 12, 2026
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| if (res == 0.0) | ||
| res= 0.0; |
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To a human, this looks like something a compiler might consider no-op.
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… but, checking on https://godbolt.org/, it’s not the case for either GCC -O3 or Clang -O3.
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Really don't know why it works, but when I remove the condition, it prints -0 when run ( select -''; ), which is the issue
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Normalize -0.0 to +0.0 in Item_func_neg::real_op() to match binary subtraction behavior. Add a test case in type_newdecimal.