revert back changes on FromString and static arrays

Author: h3xds1nz

src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/LengthConverter.cs

@@ -98,9 +98,7 @@ public override bool CanConvertTo(ITypeDescriptorContext typeDescriptorContext,
         /// <param name="typeDescriptorContext"> The ITypeDescriptorContext for this call. </param>
         /// <param name="cultureInfo"> The CultureInfo which is respected when converting. </param>
         /// <param name="source"> The object to convert to a double. </param>
-        public override object ConvertFrom(ITypeDescriptorContext typeDescriptorContext, 
-                                           CultureInfo cultureInfo, 
-                                           object source)
+        public override object ConvertFrom(ITypeDescriptorContext typeDescriptorContext, CultureInfo cultureInfo, object source)
         {
             if (source is not null)
             {
@@ -130,10 +128,7 @@ public override object ConvertFrom(ITypeDescriptorContext typeDescriptorContext,
         /// <param name="cultureInfo"> The CultureInfo which is respected when converting. </param>
         /// <param name="value"> The double to convert. </param>
         /// <param name="destinationType">The type to which to convert the double. </param>
-        public override object ConvertTo(ITypeDescriptorContext typeDescriptorContext, 
-                                         CultureInfo cultureInfo,
-                                         object value,
-                                         Type destinationType)
+        public override object ConvertTo(ITypeDescriptorContext typeDescriptorContext, CultureInfo cultureInfo, object value, Type destinationType)
         {
             ArgumentNullException.ThrowIfNull(destinationType);
 
@@ -174,62 +169,65 @@ public override object ConvertTo(ITypeDescriptorContext typeDescriptorContext,
         // NOTE - This code is called from FontSizeConverter, so changes will affect both.
         static internal double FromString(string s, CultureInfo cultureInfo)
         {
-            ReadOnlySpan<char> valueString = s.AsSpan().Trim();
-
+            string valueString = s.Trim();
+            string goodString = valueString.ToLowerInvariant();
+            int strLen = goodString.Length;
             int strLenUnit = 0;
             double unitFactor = 1.0;
 
-            //Auto is represented as Double.NaN
+            //Auto is represented and Double.NaN
             //properties that do not want Auto and NaN to be in their ligit values,
             //should disallow NaN in validation callbacks (same goes for negative values)
-            if (valueString.Equals("Auto", StringComparison.OrdinalIgnoreCase))
-                return double.NaN;
+            if (goodString == "auto")
+                return Double.NaN;
 
-            for (int i = 0; i < s_pixelUnitStrings.Length; i++)
+            for (int i = 0; i < PixelUnitStrings.Length; i++)
             {
                 // NOTE: This is NOT a culture specific comparison.
                 // This is by design: we want the same unit string table to work across all cultures.
-                if (valueString.EndsWith(s_pixelUnitStrings[i], StringComparison.OrdinalIgnoreCase))
+                if (goodString.EndsWith(PixelUnitStrings[i], StringComparison.Ordinal))
                 {
-                    strLenUnit = s_pixelUnitStrings[i].Length;
+                    strLenUnit = PixelUnitStrings[i].Length;
                     unitFactor = PixelUnitFactors[i];
                     break;
                 }
             }
 
-            // Remove pixel unit string if present, otherwise no-op
-            valueString = valueString.Slice(0, valueString.Length - strLenUnit);
+            //  important to substring original non-lowered string 
+            //  this allows case sensitive ToDouble below handle "NaN" and "Infinity" correctly. 
+            //  this addresses windows bug 1177408
+            valueString = valueString.Substring(0, strLen - strLenUnit);
 
             // FormatException errors thrown by Convert.ToDouble are pretty uninformative.
             // Throw a more meaningful error in this case that tells that we were attempting
             // to create a Length instance from a string.  This addresses windows bug 968884
             try
             {
-                return double.Parse(valueString, cultureInfo) * unitFactor;
+                double result = Convert.ToDouble(valueString, cultureInfo) * unitFactor;
+                return result;
             }
             catch (FormatException)
             {
-                throw new FormatException(SR.Format(SR.LengthFormatError, valueString.ToString()));
+                throw new FormatException(SR.Format(SR.LengthFormatError, valueString));
             }
         }
 
-        // This array contains string representations for unit known types.
+        // This array contains strings for unit types 
         // These are effectively "TypeConverter only" units.
         // They are all expressable in terms of the Pixel unit type and a conversion factor.
-        private static readonly string[] s_pixelUnitStrings = ["px", "in", "cm", "pt"];
-
-        /// <summary> Holds the factor value representation for units specified in <see cref="s_pixelUnitStrings"/>. </summary>
-        private static ReadOnlySpan<double> PixelUnitFactors =>
-        [ 
-            1.0,              // px - Pixel itself
-            96.0,             // in - Pixels per Inch
-            96.0 / 2.54,      // cm - Pixels per Centimeter
-            96.0 / 72.0,      // pt - Pixels per Point
-        ];
+        static private string[] PixelUnitStrings = { "px", "in", "cm", "pt" };
+        static private double[] PixelUnitFactors =
+        {
+            1.0,              // Pixel itself
+            96.0,             // Pixels per Inch
+            96.0 / 2.54,      // Pixels per Centimeter
+            96.0 / 72.0,      // Pixels per Point
+        };
 
         static internal string ToString(double l, CultureInfo cultureInfo)
         {
-            if(double.IsNaN(l)) return "Auto";
+            if (double.IsNaN(l))
+                return "Auto";
             return Convert.ToString(l, cultureInfo);
         }