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| author | Stephan Bergmann <stephan.bergmann@allotropia.de> | 2024-11-16 16:20:29 +0100 |
|---|---|---|
| committer | Stephan Bergmann <stephan.bergmann@allotropia.de> | 2024-11-16 23:27:39 +0100 |
| commit | 39f701d540d9bc7e90fa99393c2eac165e71faae (patch) | |
| tree | 3138797f5535a3c60f80c29f2146d06031257e62 | |
| parent | 2b8394b36bf1602ca3f33a00dacd18329cc91d2d (diff) | |
Avoid UBSan when negating the most negative sal_Int64 value
...as exhibited by recently added 08e566f0c97fb6cc2ee17813e81c221a8d7154c0 "add
a couple of tests for tools::BigInt"
Change-Id: Icd1080f86ccd985868fce34d6f86e2706acd58df
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/176677
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>
Tested-by: Jenkins
| -rw-r--r-- | include/tools/bigint.hxx | 8 | ||||
| -rw-r--r-- | tools/source/generic/bigint.cxx | 5 |
2 files changed, 8 insertions, 5 deletions
diff --git a/include/tools/bigint.hxx b/include/tools/bigint.hxx index 2b7d9870d3e3..2f5fd46ec26d 100644 --- a/include/tools/bigint.hxx +++ b/include/tools/bigint.hxx @@ -164,10 +164,10 @@ inline BigInt::operator sal_Int64() const case 1: return bIsNeg ? -sal_Int64(nNum[0]) : nNum[0]; case 2: - if (sal_uInt64 n = (sal_uInt64(nNum[1]) << 32) + nNum[0]; bIsNeg && n <= maxForNegInt64) - return -sal_Int64(n); // maxForNegInt64 will convert correctly - else if (!bIsNeg && n <= maxForPosInt64) - return n; + if (sal_uInt64 n = (sal_uInt64(nNum[1]) << 32) + nNum[0]; bIsNeg && n < maxForNegInt64) + return -sal_Int64(n); + else if ((bIsNeg && n == maxForNegInt64) || (!bIsNeg && n <= maxForPosInt64)) + return n; // maxForNegInt64 will convert correctly } assert(false && "out of range"); return 0; diff --git a/tools/source/generic/bigint.cxx b/tools/source/generic/bigint.cxx index 2c705e30c755..2f56ee28416d 100644 --- a/tools/source/generic/bigint.cxx +++ b/tools/source/generic/bigint.cxx @@ -25,6 +25,7 @@ #include <algorithm> #include <cmath> #include <cstring> +#include <limits> #include <span> /** @@ -461,7 +462,9 @@ BigInt::BigInt( sal_Int64 nValue ) } else { - for (sal_uInt64 n = static_cast<sal_uInt64>(bIsNeg ? -nValue : nValue); n != 0; n >>= 32) + for (sal_uInt64 n = static_cast<sal_uInt64>( + (bIsNeg && nValue != std::numeric_limits<sal_Int64>::min()) ? -nValue : nValue); + n != 0; n >>= 32) nNum[nLen++] = static_cast<sal_uInt32>(n); } } |