1f05dbd06d896849d16b026bfc3315ee8b73a89f util: Avoid invalid integer negation in ValueFromAmount: make ValueFromAmount(const CAmount& n) well-defined also when n is std::numeric_limits<CAmount>::min() (practicalswift)
7cc75c9ba38e516067e5a4ab84311c62ddddced7 util: Avoid invalid integer negation in FormatMoney: make FormatMoney(const CAmount& n) well-defined also when n is std::numeric_limits<CAmount>::min() (practicalswift)
Pull request description:
Avoid invalid integer negation in `FormatMoney` and `ValueFromAmount`.
Fixes#20402.
Before this patch:
```
$ CC=clang CXX=clang++ ./configure --with-sanitizers=undefined
$ make -C src/ test/test_bitcoin
$ src/test/test_bitcoin -t rpc_tests/rpc_format_monetary_values -t util_tests/util_FormatMoney
core_write.cpp:21:29: runtime error: negation of -9223372036854775808 cannot be represented in type 'CAmount'
(aka 'long'); cast to an unsigned type to negate this value to itself
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior core_write.cpp:21:29 in
test/rpc_tests.cpp(186): error: in "rpc_tests/rpc_format_monetary_values":
check ValueFromAmount(std::numeric_limits<CAmount>::min()).write() == "-92233720368.54775808" has failed
[--92233720368.-54775808 != -92233720368.54775808]
util/moneystr.cpp:16:34: runtime error: negation of -9223372036854775808 cannot be represented in type 'CAmount'
(aka 'long'); cast to an unsigned type to negate this value to itself
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior util/moneystr.cpp:16:34 in
test/util_tests.cpp(1188): error: in "util_tests/util_FormatMoney":
check FormatMoney(std::numeric_limits<CAmount>::min()) == "-92233720368.54775808" has failed
[--92233720368.-54775808 != -92233720368.54775808]
```
After this patch:
```
$ CC=clang CXX=clang++ ./configure --with-sanitizers=undefined
$ make -C src/ test/test_bitcoin
$ src/test/test_bitcoin -t rpc_tests/rpc_format_monetary_values -t util_tests/util_FormatMoney
```
ACKs for top commit:
laanwj:
re-ACK 1f05dbd06d896849d16b026bfc3315ee8b73a89f
Tree-SHA512: 5aaeb8e2178f1597921f53c12bdfc2f3d5993d10c41658dcd25943e54e8cc2116a411bc71d928f890b33bc0b3761a8ee4449b0532bce41125b6c60692808c8c3
47b99ab1a9