Fix big negative numbers printing incorrect decimals in num_real

core/string/ustring.cpp

@@ -1567,10 +1567,11 @@ String String::num_real(double p_num, bool p_trailing) {
 #else
 	int decimals = 6;
 #endif
-	// We want to align the digits to the above sane default, so we only
-	// need to subtract log10 for numbers with a positive power of ten.
-	if (p_num > 10) {
-		decimals -= (int)floor(log10(p_num));
+	// We want to align the digits to the above sane default, so we only need
+	// to subtract log10 for numbers with a positive power of ten magnitude.
+	double abs_num = Math::abs(p_num);
+	if (abs_num > 10) {
+		decimals -= (int)floor(log10(abs_num));
 	}
 	return num(p_num, decimals);
 }

tests/core/string/test_string.h

@@ -411,9 +411,13 @@ TEST_CASE("[String] Number to string") {
 	CHECK(String::num_real(3.141593) == "3.141593");
 	CHECK(String::num_real(3.141) == "3.141"); // No trailing zeros.
 #ifdef REAL_T_IS_DOUBLE
+	CHECK_MESSAGE(String::num_real(123.456789) == "123.456789", "Prints the appropriate amount of digits for real_t = double.");
+	CHECK_MESSAGE(String::num_real(-123.456789) == "-123.456789", "Prints the appropriate amount of digits for real_t = double.");
 	CHECK_MESSAGE(String::num_real(Math_PI) == "3.14159265358979", "Prints the appropriate amount of digits for real_t = double.");
 	CHECK_MESSAGE(String::num_real(3.1415f) == "3.1414999961853", "Prints more digits of 32-bit float when real_t = double (ones that would be reliable for double) and no trailing zero.");
 #else
+	CHECK_MESSAGE(String::num_real(123.456789) == "123.4568", "Prints the appropriate amount of digits for real_t = float.");
+	CHECK_MESSAGE(String::num_real(-123.456789) == "-123.4568", "Prints the appropriate amount of digits for real_t = float.");
 	CHECK_MESSAGE(String::num_real(Math_PI) == "3.141593", "Prints the appropriate amount of digits for real_t = float.");
 	CHECK_MESSAGE(String::num_real(3.1415f) == "3.1415", "Prints only reliable digits of 32-bit float when real_t = float.");
 #endif // REAL_T_IS_DOUBLE