Merge #14585: refactor: remove usage of locale dependent std::isspace

15db77f4dd Don't rely on locale dependent functions in base_blob<BITS>::SetHex(...) (uint256), DecodeBase58(...), ParseMoney(...) and ParseHex(...) (practicalswift)

Pull request description:

  Don't rely on locale dependent function `std::isspace` in `base_blob<BITS>::SetHex(...)` (uint256), `DecodeBase58(...)`, `ParseMoney(...)` and `ParseHex(...)`.

  Rationale:

  ```
  $ uname -s
  Darwin
  $ cat poc.cpp
  #include <iostream>
  #include <locale>

  int main(void) {
      setlocale(LC_ALL, "");
      std::cout << std::isspace(133) << ' ' << std::isspace(154) << ' ' << std::isspace(160);
      std::cout << '\n';
  }
  $ clang++ -o poc poc.cpp
  $ ./poc
  1 0 1
  $ LC_ALL=en_US ./poc
  1 0 1
  $ LC_ALL=C ./poc
  0 0 0
  $ LC_ALL=ru_RU.KOI8-R ./poc # an "interesting" locale
  0 1 0
  ```

Tree-SHA512: 4eafb267342b8a777da6cca07c353afd1f90f3fc1d91e01f526f1b384a2b97c1da25b7bd7dfc300655182a4eaec6a4bea855a45723ab53c750a734b60e1e3c9f

src/base58.cpp

@@ -36,7 +36,7 @@ static const int8_t mapBase58[256] = {
 bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
 {
     // Skip leading spaces.
-    while (*psz && isspace(*psz))
+    while (*psz && IsSpace(*psz))
         psz++;
     // Skip and count leading '1's.
     int zeroes = 0;
@@ -50,7 +50,7 @@ bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
     std::vector<unsigned char> b256(size);
     // Process the characters.
     static_assert(sizeof(mapBase58)/sizeof(mapBase58[0]) == 256, "mapBase58.size() should be 256"); // guarantee not out of range
-    while (*psz && !isspace(*psz)) {
+    while (*psz && !IsSpace(*psz)) {
         // Decode base58 character
         int carry = mapBase58[(uint8_t)*psz];
         if (carry == -1)  // Invalid b58 character
@@ -66,7 +66,7 @@ bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
         psz++;
     }
     // Skip trailing spaces.
-    while (isspace(*psz))
+    while (IsSpace(*psz))
         psz++;
     if (*psz != 0)
         return false;

src/uint256.cpp

@@ -33,7 +33,7 @@ void base_blob<BITS>::SetHex(const char* psz)
     memset(m_data, 0, sizeof(m_data));
 
     // skip leading spaces
-    while (isspace(*psz))
+    while (IsSpace(*psz))
         psz++;
 
     // skip 0x

src/util/moneystr.cpp

@@ -41,7 +41,7 @@ bool ParseMoney(const char* pszIn, CAmount& nRet)
     std::string strWhole;
     int64_t nUnits = 0;
     const char* p = pszIn;
-    while (isspace(*p))
+    while (IsSpace(*p))
         p++;
     for (; *p; p++)
     {
@@ -56,14 +56,14 @@ bool ParseMoney(const char* pszIn, CAmount& nRet)
             }
             break;
         }
-        if (isspace(*p))
+        if (IsSpace(*p))
             break;
         if (!isdigit(*p))
             return false;
         strWhole.insert(strWhole.end(), *p);
     }
     for (; *p; p++)
-        if (!isspace(*p))
+        if (!IsSpace(*p))
             return false;
     if (strWhole.size() > 10) // guard against 63 bit overflow
         return false;

src/util/strencodings.cpp

@@ -87,7 +87,7 @@ std::vector<unsigned char> ParseHex(const char* psz)
     std::vector<unsigned char> vch;
     while (true)
     {
-        while (isspace(*psz))
+        while (IsSpace(*psz))
             psz++;
         signed char c = HexDigit(*psz++);
         if (c == (signed char)-1)
@@ -272,7 +272,7 @@ std::string DecodeBase32(const std::string& str, bool* pf_invalid)
 {
     if (str.empty()) // No empty string allowed
         return false;
-    if (str.size() >= 1 && (isspace(str[0]) || isspace(str[str.size()-1]))) // No padding allowed
+    if (str.size() >= 1 && (IsSpace(str[0]) || IsSpace(str[str.size()-1]))) // No padding allowed
         return false;
     if (!ValidAsCString(str)) // No embedded NUL characters allowed
         return false;

src/util/strencodings.h

@@ -84,6 +84,21 @@ constexpr bool IsDigit(char c)
     return c >= '0' && c <= '9';
 }
 
+/**
+ * Tests if the given character is a whitespace character. The whitespace characters
+ * are: space, form-feed ('\f'), newline ('\n'), carriage return ('\r'), horizontal
+ * tab ('\t'), and vertical tab ('\v').
+ *
+ * This function is locale independent. Under the C locale this function gives the
+ * same result as std::isspace.
+ *
+ * @param[in] c     character to test
+ * @return          true if the argument is a whitespace character; otherwise false
+ */
+constexpr inline bool IsSpace(char c) noexcept {
+    return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v';
+}
+
 /**
  * Convert string to signed 32-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,

test/lint/lint-locale-dependence.sh

@@ -3,7 +3,6 @@
 export LC_ALL=C
 
 KNOWN_VIOLATIONS=(
-    "src/base58.cpp:.*isspace"
     "src/bench/string_cast.cpp.*atoi"
     "src/dash-tx.cpp.*stoul"
     "src/dash-tx.cpp.*trim_right"
@@ -29,14 +28,11 @@ KNOWN_VIOLATIONS=(
     "src/test/getarg_tests.cpp.*split"
     "src/torcontrol.cpp:.*atoi"
     "src/torcontrol.cpp:.*strtol"
-    "src/uint256.cpp:.*isspace"
     "src/uint256.cpp:.*tolower"
     "src/util/system.cpp:.*atoi"
     "src/util/system.cpp:.*tolower"
     "src/util/moneystr.cpp:.*isdigit"
-    "src/util/moneystr.cpp:.*isspace"
     "src/util/strencodings.cpp:.*atoi"
-    "src/util/strencodings.cpp:.*isspace"
     "src/util/strencodings.cpp:.*strtol"
     "src/util/strencodings.cpp:.*strtoll"
     "src/util/strencodings.cpp:.*strtoul"