[vs17.9] [ClickOnce] [GB18030] Workaround for incorrect encoding of chars in the PUA range of file paths

eng/Versions.props

@@ -2,7 +2,7 @@
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the MIT license. See License.txt in the project root for full license information. -->
 <Project>
   <PropertyGroup>
-    <VersionPrefix>17.9.4</VersionPrefix><DotNetFinalVersionKind>release</DotNetFinalVersionKind>
+    <VersionPrefix>17.9.5</VersionPrefix><DotNetFinalVersionKind>release</DotNetFinalVersionKind>
     <PackageValidationBaselineVersion>17.8.3</PackageValidationBaselineVersion>
     <AssemblyVersion>15.1.0.0</AssemblyVersion>
     <PreReleaseVersionLabel>preview</PreReleaseVersionLabel>

src/Tasks/ManifestUtil/PathUtil.cs

@@ -45,6 +45,24 @@ public static string Format(string path)
 
             string resolvedPath = Resolve(path);
             Uri u = new Uri(resolvedPath);
+            //
+            // GB18030: Uri class does not correctly encode chars in the PUA range for implicit 
+            // file paths (paths without explicit scheme):
+            // https://github.com/dotnet/runtime/issues/89538
+            // Workaround is to use UriBuilder with the file scheme specified explicitly to 
+            // correctly encode the PUA chars.
+            //
+            if (Uri.UriSchemeFile.Equals(u.Scheme, StringComparison.OrdinalIgnoreCase) &&
+                !IsAsciiString(resolvedPath))
+            {
+                UriBuilder builder = new UriBuilder()
+                {
+                    Scheme = Uri.UriSchemeFile,
+                    Host = string.Empty,
+                    Path = resolvedPath,
+                };
+                u = builder.Uri;
+            }
             return u.AbsoluteUri;
         }
 
@@ -209,5 +227,15 @@ public static string Resolve(string path)
             // if not unc or url then it must be a local disk path...
             return Path.GetFullPath(path); // make sure it's a full path
         }
+
+        private static bool IsAsciiString(string str)
+        {
+            foreach (char c in str)
+            {
+                if (c > 127)
+                {  return false; }
+            }
+            return true;
+        }
     }
 }