From: Stephen Toub <stoub@microsoft.com>
Date: Tue, 19 Jun 2018 21:28:32 +0000 (-0400)
Subject: Avoid two unnecessary string.Substring calls in PunycodeDecode (dotnet/coreclr#18546)
X-Git-Tag: submit/tizen/20210909.063632~11030^2~4563
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f8086fa86ba1b95ebe0923335b4ebe1f7c6f9a3c;p=platform%2Fupstream%2Fdotnet%2Fruntime.git

Avoid two unnecessary string.Substring calls in PunycodeDecode (dotnet/coreclr#18546)



Commit migrated from https://github.com/dotnet/coreclr/commit/90850134cb27a499a2bf8e6a545f58ae057ded41
---

diff --git a/src/libraries/System.Private.CoreLib/src/System/Globalization/IdnMapping.cs b/src/libraries/System.Private.CoreLib/src/System/Globalization/IdnMapping.cs
index 6da6f79..8c9c2de 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Globalization/IdnMapping.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Globalization/IdnMapping.cs
@@ -638,10 +638,10 @@ namespace System.Globalization
 
                 // See if this section's ASCII or ACE
                 if (ascii.Length < c_strAcePrefix.Length + iAfterLastDot || 
-                    !ascii.Substring(iAfterLastDot,c_strAcePrefix.Length).Equals(c_strAcePrefix, StringComparison.OrdinalIgnoreCase))
+                    string.Compare(ascii, iAfterLastDot, c_strAcePrefix, 0, c_strAcePrefix.Length, StringComparison.OrdinalIgnoreCase) != 0)
                 {
                     // Its ASCII, copy it
-                    output.Append(ascii.Substring(iAfterLastDot, iNextDot - iAfterLastDot));
+                    output.Append(ascii, iAfterLastDot, iNextDot - iAfterLastDot);
                 }
                 else
                 {