[Demangling] Avoid UB call to memcpy(). #68187
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When appending to an empty `CharVector`, we were inadvertently relying on `memcpy(NewObjects, NULL, 0)` being a no-op, whereas in practice the C standard says it's UB because of the `NULL` pointer. Fix by only calling `memcpy()` if we actually have bytes to copy. rdar://114447171
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mikeash
approved these changes
Aug 29, 2023
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When appending to an empty
CharVector, we were inadvertently relying onmemcpy(NewObjects, NULL, 0)being a no-op, whereas in practice the C standard says it's UB because of theNULLpointer.Fix by only calling
memcpy()if we actually have bytes to copy.rdar://114447171