Fix issue with url encoding for request properties with values that have a majority of characters that need to be percent encoded (#3875)

Author: normj

generator/.DevConfigs/4a47973b-5c80-465d-8064-f224697e4182.json

@@ -0,0 +1,9 @@
+{
+  "core": {
+    "updateMinimum": true,
+    "type": "patch",
+    "changeLogMessages": [
+      "Fix issue with url encoding for request properties with values that have a majority of characters that need to be percent encoded"
+    ]
+  }
+}

sdk/src/Core/Amazon.Util/AWSSDKUtils.cs

@@ -1044,16 +1044,23 @@ public static string UrlEncode(int rfcNumber, string data, bool path)
                 var encoding = Encoding.UTF8;
 
                 var dataByteLength = encoding.GetMaxByteCount(dataAsSpan.Length);
-                var encodedByteLength = 2 * dataByteLength;
+
+                // The dataBuffer byte span will be used to store utf8 bytes of the data be encoded at the end and
+                // url encoded at the start of dataBuffer. As the utf8 bytes are iterated and percent encoded at the 
+                // beginning dataBuffer the utf8 bytes at the end will be overwritten by the percent encoding.
+                // The size of the dataBuffer needs to be 3 times the size utf8 max encoding to handle the worst
+                // case scenario of every character needing to be percent encoding taking 3 bytes. 
+                var encodedByteLength = 3 * dataByteLength;
                 var dataBuffer = encodedByteLength <= MaxStackLimit
                     ? stackalloc byte[MaxStackLimit]
                     : sharedDataBuffer = ArrayPool<byte>.Shared.Rent(encodedByteLength);
+
                 // Instead of stack allocating or renting two buffers we use one buffer with at least twice the capacity of the
                 // max encoding length. Then store the character data as bytes in the second half reserving the first half of the buffer 
                 // for the encoded representation.
                 var encodingBuffer = dataBuffer.Slice(dataBuffer.Length - dataByteLength);
                 var bytesWritten = encoding.GetBytes(dataAsSpan, encodingBuffer);
-            
+
                 var index = 0;
                 foreach (var symbol in encodingBuffer.Slice(0, bytesWritten))
                 {

sdk/test/NetStandard/UnitTests/Core/AWSSDKUtilsTests.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using Amazon.Util;
 using System.Text;
 using Amazon.Runtime.Internal;
@@ -67,6 +67,8 @@ public void DetermineService(string url, string expectedService)
         [Theory]
         [InlineData("value, with special chars!", "value%2C%20with%20special%20chars%21")]
         [InlineData("value, with special chars and path {/+:}", "value%2C%20with%20special%20chars%20and%20path%20%7B%2F%2B%3A%7D")]
+        [InlineData("紙_一般_児童手当等の受給資格及び児童手当の額についての認定請求公金非対応", "%E7%B4%99_%E4%B8%80%E8%88%AC_%E5%85%90%E7%AB%A5%E6%89%8B%E5%BD%93%E7%AD%89%E3%81%AE%E5%8F%97%E7%B5%A6%E8%B3%87%E6%A0%BC%E5%8F%8A%E3%81%B3%E5%85%90%E7%AB%A5%E6%89%8B%E5%BD%93%E3%81%AE%E9%A1%8D%E3%81%AB%E3%81%A4%E3%81%84%E3%81%A6%E3%81%AE%E8%AA%8D%E5%AE%9A%E8%AB%8B%E6%B1%82%E5%85%AC%E9%87%91%E9%9D%9E%E5%AF%BE%E5%BF%9C")]
+
         public void UrlEncodeWithoutPath(string input, string expected)
         {
             var encoded = AWSSDKUtils.UrlEncode(input, path: false);
@@ -78,6 +80,7 @@ public void UrlEncodeWithoutPath(string input, string expected)
         [InlineData("\ud83d\ude02 value, with special chars!", "%F0%9F%98%82%20value,%20with%20special%20chars!")]
         [InlineData("value, with special chars!", "value,%20with%20special%20chars!")]
         [InlineData("value, with special chars and path {/+:}", "value,%20with%20special%20chars%20and%20path%20%7B/+%3A%7D")]
+        [InlineData("紙_一般_児童手当等の受給資格及び児童手当の額についての認定請求公金非対応", "%E7%B4%99_%E4%B8%80%E8%88%AC_%E5%85%90%E7%AB%A5%E6%89%8B%E5%BD%93%E7%AD%89%E3%81%AE%E5%8F%97%E7%B5%A6%E8%B3%87%E6%A0%BC%E5%8F%8A%E3%81%B3%E5%85%90%E7%AB%A5%E6%89%8B%E5%BD%93%E3%81%AE%E9%A1%8D%E3%81%AB%E3%81%A4%E3%81%84%E3%81%A6%E3%81%AE%E8%AA%8D%E5%AE%9A%E8%AB%8B%E6%B1%82%E5%85%AC%E9%87%91%E9%9D%9E%E5%AF%BE%E5%BF%9C")]
         public void UrlEncodeWithPath(string input, string expected)
         {
             var encoded = AWSSDKUtils.UrlEncode(input, path: true);