Replace use of locale dependent atoi(…) with locale-independent std::from_chars(…) (C++17)

test: Add test cases for LocaleIndependentAtoi

fuzz: Assert legacy atoi(s) == LocaleIndependentAtoi<int>(s)

fuzz: Assert legacy atoi64(s) == LocaleIndependentAtoi<int64_t>(s)

1 files changed, 9 insertions, 11 deletions

diff --git a/src/util/system.cpp b/src/util/system.cpp
index 4defeed4ce..79c08816fa 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -158,16 +158,14 @@ std::streampos GetFileSize(const char* path, std::streamsize max) {
 /**
  * Interpret a string argument as a boolean.
  *
- * The definition of atoi() requires that non-numeric string values like "foo",
- * return 0. This means that if a user unintentionally supplies a non-integer
- * argument here, the return value is always false. This means that -foo=false
- * does what the user probably expects, but -foo=true is well defined but does
- * not do what they probably expected.
+ * The definition of LocaleIndependentAtoi<int>() requires that non-numeric string values
+ * like "foo", return 0. This means that if a user unintentionally supplies a
+ * non-integer argument here, the return value is always false. This means that
+ * -foo=false does what the user probably expects, but -foo=true is well defined
+ * but does not do what they probably expected.
  *
- * The return value of atoi() is undefined when given input not representable as
- * an int. On most systems this means string value between "-2147483648" and
- * "2147483647" are well defined (this method will return true). Setting
- * -txindex=2147483648 on most systems, however, is probably undefined.
+ * The return value of LocaleIndependentAtoi<int>(...) is zero when given input not
+ * representable as an int.
  *
  * For a more extensive discussion of this topic (and a wide range of opinions
  * on the Right Way to change this code), see PR12713.
@@ -176,7 +174,7 @@ static bool InterpretBool(const std::string& strValue)
 {
     if (strValue.empty())
         return true;
-    return (atoi(strValue) != 0);
+    return (LocaleIndependentAtoi<int>(strValue) != 0);
 }
 
 static std::string SettingName(const std::string& arg)
@@ -594,7 +592,7 @@ std::string ArgsManager::GetArg(const std::string& strArg, const std::string& st
 int64_t ArgsManager::GetIntArg(const std::string& strArg, int64_t nDefault) const
 {
     const util::SettingsValue value = GetSetting(strArg);
-    return value.isNull() ? nDefault : value.isFalse() ? 0 : value.isTrue() ? 1 : value.isNum() ? value.get_int64() : atoi64(value.get_str());
+    return value.isNull() ? nDefault : value.isFalse() ? 0 : value.isTrue() ? 1 : value.isNum() ? value.get_int64() : LocaleIndependentAtoi<int64_t>(value.get_str());
 }
 
 bool ArgsManager::GetBoolArg(const std::string& strArg, bool fDefault) const