More fixes

Author: kunitoki

modules/yup_core/text/yup_String.h

@@ -1193,11 +1193,10 @@ class YUP_API String final
             return "0";
         }
 
-        auto numDigitsBeforePoint = (int) std::ceil (std::log10 (number < 0 ? -number : number));
-
-        auto shift = numberOfSignificantFigures - numDigitsBeforePoint;
-        auto factor = std::pow (10.0, shift);
-        auto rounded = std::round (number * factor) / factor;
+        const auto numDigitsBeforePoint = (int) std::floor (std::log10 (std::abs (number)) + DecimalType (1));
+        const auto shift = numberOfSignificantFigures - numDigitsBeforePoint;
+        const auto factor = std::pow (10.0, shift);
+        const auto rounded = std::round (number * factor) / factor;
 
         std::stringstream ss;
         ss << std::fixed << std::setprecision (std::max (shift, 0)) << rounded;

tests/yup_core/yup_String.cpp

@@ -571,6 +571,18 @@ TEST_F (StringTests, SignificantFigures)
     EXPECT_EQ (String::toDecimalStringWithSignificantFigures (2.8647, 6), String ("2.86470"));
 
     EXPECT_EQ (String::toDecimalStringWithSignificantFigures (-0.0000000000019, 1), String ("-0.000000000002"));
+
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (0.001, 7), String ("0.001000000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (0.01, 7), String ("0.01000000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (0.1, 7), String ("0.1000000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (1, 7), String ("1.000000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (10, 7), String ("10.00000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (100, 7), String ("100.0000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (1000, 7), String ("1000.000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (10000, 7), String ("10000.00"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (100000, 7), String ("100000.0"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (1000000, 7), String ("1000000"));
+    EXPECT_EQ (String::toDecimalStringWithSignificantFigures (10000000, 7), String ("10000000"));
 }
 
 TEST_F (StringTests, FloatTrimming)