diff --git a/lib/mathlib.cpp b/lib/mathlib.cpp
index bb0fb1147..3fd336702 100644
--- a/lib/mathlib.cpp
+++ b/lib/mathlib.cpp
@@ -598,13 +598,107 @@ bool MathLib::isLessEqual(const std::string &first, const std::string &second)
     return toDoubleNumber(first) <= toDoubleNumber(second);
 }
 
-bool MathLib::isNullValue(const std::string &str)
+bool MathLib::isNullValue(const std::string &s)
 {
-    for (size_t i = 0; i < str.size(); i++) {
-        if (std::isdigit(static_cast<unsigned char>(str[i])) && str[i] != '0') // May not contain digits other than 0
+    enum {START, PLUSMINUS, LEADING_ZERO, BIN_OR_HEX_PREFIX, DOT, TRAILING_ZERO, TRAILING_F, ZERO, E, E_PLUSMINUS, E_DIGIT} state = START;
+    for (std::string::const_iterator it = s.begin(); it != s.end(); ++it) {
+        switch (state) {
+        case START:
+            if (*it == '+' || *it == '-')
+                state = PLUSMINUS;
+            else if (*it == '0')
+                state = LEADING_ZERO;
+            else if (*it == '.')
+                state = DOT;
+            else
+                return isValidSuffix(it, s.end());
+            break;
+        case PLUSMINUS:
+            if (*it == '0')
+                state = LEADING_ZERO;
+            else
+                return false;
+            break;
+        case LEADING_ZERO:
+            if (*it == '0')
+                state = LEADING_ZERO;
+            else if (*it == 'b' || *it == 'B')
+                state = BIN_OR_HEX_PREFIX;
+            else if (*it == 'x' || *it == 'X')
+                state = BIN_OR_HEX_PREFIX;
+            else if (*it == '.')
+                state = DOT;
+            else if (*it == 'e' || *it == 'E')
+                state = E;
+            else
+                return isValidSuffix(it, s.end());
+            break;
+        case BIN_OR_HEX_PREFIX:
+            if (*it == '0')
+                state = ZERO;
+            else
+                return false;
+            break;
+        case ZERO:
+            if (*it == '0')
+                state = ZERO;
+            else
+                return isValidSuffix(it, s.end());
+            break;
+        case DOT:
+            if (*it == '0')
+                state = TRAILING_ZERO;
+            else if (*it == 'f' || *it == 'F')
+                state = TRAILING_F;
+            else if (*it == 'e' || *it == 'E')
+                state = E;
+            else
+                return false;
+            break;
+        case E:
+            if (*it == '+' || *it == '-')
+                state = E_PLUSMINUS;
+            else if (isdigit(*it))
+                state = E_DIGIT;
+            else
+                return false;
+            break;
+        case E_PLUSMINUS:
+            if (isdigit(*it))
+                state = E_DIGIT;
+            else
+                return false;
+            break;
+        case E_DIGIT:
+            if (isdigit(*it))
+                state = E_DIGIT;
+            else if (*it == 'f' || *it == 'F')
+                state = TRAILING_F;
+            else
+                return false;
+            break;
+        case TRAILING_ZERO:
+            if (*it == '0')
+                state = TRAILING_ZERO;
+            else if (*it == 'f' || *it == 'F')
+                state = TRAILING_F;
+            else if (*it == 'e' || *it == 'E')
+                state = E;
+            else
+                return false;
+            break;
+        default:
             return false;
+        }
     }
-    return !str.empty() && (std::isdigit(static_cast<unsigned char>(str[0])) || str[0] == '-' || str[0] == '+'); // Has to be a number
+    return state == LEADING_ZERO || state == ZERO || state == DOT || state == E_DIGIT || state == TRAILING_ZERO || state == TRAILING_F;
+    /*
+        for (size_t i = 0; i < str.size(); i++) {
+            if (std::isdigit(static_cast<unsigned char>(str[i])) && str[i] != '0') // May not contain digits other than 0
+                return false;
+        }
+        return !str.empty() && (std::isdigit(static_cast<unsigned char>(str[0])) || str[0] == '-' || str[0] == '+'); // Has to be a number
+    */
 }
 
 bool MathLib::isOctalDigit(char c)
diff --git a/test/testmathlib.cpp b/test/testmathlib.cpp
index 60175cc04..0bb102895 100644
--- a/test/testmathlib.cpp
+++ b/test/testmathlib.cpp
@@ -45,7 +45,8 @@ private:
         TEST_CASE(calculate);
         TEST_CASE(calculate1);
         TEST_CASE(convert);
-        TEST_CASE(naninf)
+        TEST_CASE(naninf);
+        TEST_CASE(isNullValue);
     }
 
     void isGreater() const {
@@ -601,6 +602,169 @@ private:
         ASSERT_EQUALS("inf.0", MathLib::divide("3.0", "0.0")); // inf
         ASSERT_EQUALS("-inf.0", MathLib::divide("-3.0", "0.0")); // -inf (#5142)
     }
+
+    void isNullValue() const {
+        // inter zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0"));
+        // inter zero value (octal)
+        ASSERT_EQUALS(true, MathLib::isNullValue("00"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00"));
+        // inter zero value (hex)
+        ASSERT_EQUALS(true, MathLib::isNullValue("0x0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0x0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0x0"));
+        // unsigned integer zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0U"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0U"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0U"));
+        // long integer zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0L"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0L"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0L"));
+        // unsigned long integer zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0UL"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0UL"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0UL"));
+        // unsigned long integer zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0LU"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0LU"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0LU"));
+        // long long integer zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0LL"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0LL"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0LL"));
+        // long long unsigend zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0LLU"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0LLU"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0LLU"));
+        // unsigned long long zero value
+        ASSERT_EQUALS(true, MathLib::isNullValue("0ULL"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0ULL"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0ULL"));
+        // floating pointer zero value (no trailing zero after dot)
+        ASSERT_EQUALS(true, MathLib::isNullValue("0."));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0."));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0."));
+        // floating pointer zero value (1 trailing zero after dot)
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.0"));
+        // floating pointer zero value (3 trailing zeros after dot)
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.000"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.000"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.000"));
+        // floating pointer zero value (no trailing zero after dot)
+        ASSERT_EQUALS(true, MathLib::isNullValue("00."));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00."));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00."));
+        // floating pointer zero value (1 trailing zero after dot)
+        ASSERT_EQUALS(true, MathLib::isNullValue("00.0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00.0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00.0"));
+        // floating pointer zero value (3 trailing zero after dot)
+        ASSERT_EQUALS(true, MathLib::isNullValue("00.000"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00.000"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00.000"));
+        // floating pointer zero value (3 trailing zero after dot)
+        ASSERT_EQUALS(true, MathLib::isNullValue(".000"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E0"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E1"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E1"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E1"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E42"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E42"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E42"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E429999"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E429999"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E429999"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E+1"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E+1"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E+1"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E+42"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E+42"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E+42"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E+429999"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E+429999"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E+429999"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E-1"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E-1"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E-1"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E-42"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E-42"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E-42"));
+        // integer scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0E-429999"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0E-429999"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0E-429999"));
+        // floating point scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.E0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.E0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.E0"));
+        // floating point scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.E-0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.E-0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.E+0"));
+        // floating point scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.E+0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.E+0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.E+0"));
+        // floating point scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.00E-0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.00E-0"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.00E-0"));
+        // floating point scientific notation
+        ASSERT_EQUALS(true, MathLib::isNullValue("00000.00E-000000000"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00000.00E-000000000"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00000.00E-000000000"));
+        // floating point scientific notation (suffix f)
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.f"));
+        // floating point scientific notation (suffix f)
+        ASSERT_EQUALS(true, MathLib::isNullValue("0.0f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+0.0f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-0.0f"));
+        // floating point scientific notation (suffix f)
+        ASSERT_EQUALS(true, MathLib::isNullValue("00.0f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00.0f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00.0f"));
+        // floating point scientific notation (suffix f)
+        ASSERT_EQUALS(true, MathLib::isNullValue("00.00f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00.00f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00.00f"));
+        // floating point scientific notation (suffix f)
+        ASSERT_EQUALS(true, MathLib::isNullValue("00.00E+1f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("+00.00E+1f"));
+        ASSERT_EQUALS(true, MathLib::isNullValue("-00.00E+1f"));
+
+        // negative testing
+        ASSERT_EQUALS(false, MathLib::isNullValue("0.1"));
+        ASSERT_EQUALS(false, MathLib::isNullValue("1.0"));
+        ASSERT_EQUALS(false, MathLib::isNullValue("0.01"));
+        ASSERT_EQUALS(false, MathLib::isNullValue("-00.01e-12"));
+        ASSERT_EQUALS(false, MathLib::isNullValue("-00.01e+12"));
+        ASSERT_EQUALS(false, MathLib::isNullValue(""));
+        ASSERT_EQUALS(false, MathLib::isNullValue("x"));
+        ASSERT_EQUALS(false, MathLib::isNullValue("garbage"));
+        // suffix LUL is not allowed
+        ASSERT_EQUALS(false, MathLib::isNullValue("0LUL"));
+        ASSERT_EQUALS(false, MathLib::isNullValue("+0LUL"));
+        ASSERT_EQUALS(false, MathLib::isNullValue("-0LUL"));
+    }
 };
 
 REGISTER_TEST(TestMathLib)