Fix ResXFileRef/Bitmap href paths in translated .resx/.vsct: relative instead of absolute

src/Microsoft.DotNet.XliffTasks.Tests/ResxDocumentTests.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using XliffTasks.Model;
@@ -49,34 +50,51 @@ public void BasicLoadAndTranslate()
         }
 
         [Fact]
-        public void RewriteFileReferenceToAbsoluteInDestinyFolder()
+        public void RewriteFileReferenceToRelativePathFromOutputFolder()
         {
-            string sourceFolder = Directory.GetCurrentDirectory();
-            string expectedAbsoluteLocation = Path.Combine(
-              Directory.GetCurrentDirectory(),
-              @"Resources\Package.ico".Replace('\\', Path.DirectorySeparatorChar));
+            // Simulates: source .resx is in src/MyProject/, translated output .resx is in artifacts/obj/MyProject.xlf/
+            // The resource file at src/MyProject/Resources/Package.ico should be referenced as
+            // a relative path from the output directory.
+            string tempBase = Path.Combine(Path.GetTempPath(), "xliff-test-" + Path.GetRandomFileName());
+            string sourceFolder = Path.Combine(tempBase, "src", "MyProject");
+            string outputFolder = Path.Combine(tempBase, "artifacts", "obj", "MyProject.xlf");
+            string sourceFullPath = Path.Combine(sourceFolder, "Resources.resx");
+            string outputFullPath = Path.Combine(outputFolder, "MyProject.resx");
+
+            string resourceRelativePath = Path.Combine("Resources", "Package.ico");
+            string resourceAbsolutePath = Path.GetFullPath(Path.Combine(sourceFolder, resourceRelativePath));
+
+            // Compute expected relative path from output directory to resource file
+            Uri fromUri = new Uri(outputFolder.TrimEnd(Path.DirectorySeparatorChar) + Path.DirectorySeparatorChar);
+            Uri toUri = new Uri(resourceAbsolutePath);
+            string expectedRelativePath = Uri.UnescapeDataString(fromUri.MakeRelativeUri(toUri).ToString())
+                .Replace('/', Path.DirectorySeparatorChar);
+
             string source =
-@"<root>
+$@"<root>
   <data name=""400"" type=""System.Resources.ResXFileRef, System.Windows.Forms"">
-    <value>Resources\Package.ico;System.Drawing.Icon, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
+    <value>{resourceRelativePath};System.Drawing.Icon, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
   </data>
 </root>";
 
             string expectedTranslation =
-@"<root>
+$@"<root>
   <data name=""400"" type=""System.Resources.ResXFileRef, System.Windows.Forms"">
-    <value>ABSOLUTEPATH;System.Drawing.Icon, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
+    <value>{expectedRelativePath};System.Drawing.Icon, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
   </data>
-</root>".Replace("ABSOLUTEPATH", expectedAbsoluteLocation);
+</root>";
 
             ResxDocument document = new();
             StringWriter writer = new();
             document.Load(new StringReader(source));
-            document.RewriteRelativePathsToAbsolute(
-                Path.Combine(sourceFolder, "Resources.resx"));
+            document.RewriteRelativePathsForOutputPath(sourceFullPath, outputFullPath);
             document.Save(writer);
 
             AssertEx.EqualIgnoringLineEndings(expectedTranslation, writer.ToString());
+
+            // The path in the output must NOT be absolute — it must be relative,
+            // so the translated .resx remains valid after the repo is renamed or moved.
+            Assert.DoesNotContain(tempBase, writer.ToString());
         }
 
 

src/Microsoft.DotNet.XliffTasks.Tests/VsctDocumentTests.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using XliffTasks.Model;
@@ -71,35 +72,47 @@ public void BasicLoadAndTranslate()
         }
 
         [Fact]
-        public void RewriteHrefOfImageToAbsoluteInDestinyFolder()
+        public void RewriteHrefOfImageToRelativePathFromOutputFolder()
         {
-            string sourceFolder = Directory.GetCurrentDirectory();
-            string expectedAbsoluteLocation = Path.Combine(
-              Directory.GetCurrentDirectory(), 
-              @"Resources\Images.png".Replace('\\', Path.DirectorySeparatorChar));
+            // Simulates: source .vsct is in src/MyProject/, translated output is in artifacts/obj/MyProject.xlf/
+            string tempBase = Path.Combine(Path.GetTempPath(), "xliff-vsct-test-" + Path.GetRandomFileName());
+            string sourceFolder = Path.Combine(tempBase, "src", "MyProject");
+            string outputFolder = Path.Combine(tempBase, "artifacts", "obj", "MyProject.xlf");
+            string sourceFullPath = Path.Combine(sourceFolder, "MyPackage.vsct");
+            string outputFullPath = Path.Combine(outputFolder, "MyPackage.vsct");
+
+            string resourceRelativePath = Path.Combine("Resources", "Images.png");
+            string resourceAbsolutePath = Path.GetFullPath(Path.Combine(sourceFolder, resourceRelativePath));
+
+            Uri fromUri = new Uri(outputFolder.TrimEnd(Path.DirectorySeparatorChar) + Path.DirectorySeparatorChar);
+            Uri toUri = new Uri(resourceAbsolutePath);
+            string expectedRelativePath = Uri.UnescapeDataString(fromUri.MakeRelativeUri(toUri).ToString())
+                .Replace('/', Path.DirectorySeparatorChar);
 
             string source =
-@"<CommandTable xmlns=""http://schemas.microsoft.com/VisualStudio/2005-10-18/CommandTable"" xmlns:xs=""http://www.w3.org/2001/XMLSchema"">
+$@"<CommandTable xmlns=""http://schemas.microsoft.com/VisualStudio/2005-10-18/CommandTable"" xmlns:xs=""http://www.w3.org/2001/XMLSchema"">
   <Bitmaps>
-    <Bitmap guid=""guidImages"" href=""Resources\Images.png"" usedList=""bmpPic1, bmpPic2, bmpPicSearch, bmpPicX, bmpPicArrows"" />
+    <Bitmap guid=""guidImages"" href=""{resourceRelativePath}"" usedList=""bmpPic1, bmpPic2, bmpPicSearch, bmpPicX, bmpPicArrows"" />
   </Bitmaps>
 </CommandTable>";
 
             string expectedTranslation =
-@"<CommandTable xmlns=""http://schemas.microsoft.com/VisualStudio/2005-10-18/CommandTable"" xmlns:xs=""http://www.w3.org/2001/XMLSchema"">
+$@"<CommandTable xmlns=""http://schemas.microsoft.com/VisualStudio/2005-10-18/CommandTable"" xmlns:xs=""http://www.w3.org/2001/XMLSchema"">
   <Bitmaps>
-    <Bitmap guid=""guidImages"" href=""ABSOLUTEPATH"" usedList=""bmpPic1, bmpPic2, bmpPicSearch, bmpPicX, bmpPicArrows"" />
+    <Bitmap guid=""guidImages"" href=""{expectedRelativePath}"" usedList=""bmpPic1, bmpPic2, bmpPicSearch, bmpPicX, bmpPicArrows"" />
   </Bitmaps>
-</CommandTable>".Replace("ABSOLUTEPATH", expectedAbsoluteLocation);
+</CommandTable>";
 
             VsctDocument document = new();
             StringWriter writer = new();
             document.Load(new StringReader(source));
-            document.RewriteRelativePathsToAbsolute(
-                        Path.Combine(sourceFolder, "Resources.resx"));
+            document.RewriteRelativePathsForOutputPath(sourceFullPath, outputFullPath);
             document.Save(writer);
 
             AssertEx.EqualIgnoringLineEndings(expectedTranslation, writer.ToString());
+
+            // The path in the output must NOT be absolute
+            Assert.DoesNotContain(tempBase, writer.ToString());
         }
 
         [Fact]
@@ -112,11 +125,12 @@ public void DoesNotNullReferenceWhenNoHRef()
   </Bitmaps>
 </CommandTable>";
 
+            string sourceFullPath = Path.Combine(Directory.GetCurrentDirectory(), "Resources.vsct");
+
             VsctDocument document = new();
             StringWriter writer = new();
             document.Load(new StringReader(source));
-            document.RewriteRelativePathsToAbsolute(
-                        Path.Combine(Directory.GetCurrentDirectory(), "Resources.resx"));
+            document.RewriteRelativePathsForOutputPath(sourceFullPath, sourceFullPath);
             document.Save(writer);
 
             AssertEx.EqualIgnoringLineEndings(source, writer.ToString());

src/Microsoft.DotNet.XliffTasks/Model/ResxDocument.cs

@@ -54,8 +54,11 @@ protected override IEnumerable<TranslatableNode> GetTranslatableNodes()
             }
         }
 
-        public override void RewriteRelativePathsToAbsolute(string sourceFullPath)
+        public override void RewriteRelativePathsForOutputPath(string sourceFullPath, string outputFullPath)
         {
+            string sourceDir = Path.GetDirectoryName(sourceFullPath);
+            string outputDir = Path.GetDirectoryName(outputFullPath);
+
             foreach (XElement node in Document.Descendants("data"))
             {
                 if (node.Attribute("type")?.Value == "System.Resources.ResXFileRef, System.Windows.Forms")
@@ -64,8 +67,8 @@ public override void RewriteRelativePathsToAbsolute(string sourceFullPath)
                     string[] splitRelativePathAndSerializedType = valueNodeOfFileRef.Value.Split(';');
                     string resourceRelativePath = splitRelativePathAndSerializedType[0].Replace('\\', Path.DirectorySeparatorChar);
 
-                    string absolutePath = Path.Combine(Path.GetDirectoryName(sourceFullPath), resourceRelativePath);
-                    splitRelativePathAndSerializedType[0] = absolutePath;
+                    string absoluteResourcePath = Path.GetFullPath(Path.Combine(sourceDir, resourceRelativePath));
+                    splitRelativePathAndSerializedType[0] = MakeRelativePath(outputDir, absoluteResourcePath);
 
                     valueNodeOfFileRef.Value = string.Join(";", splitRelativePathAndSerializedType);
                 }

src/Microsoft.DotNet.XliffTasks/Model/TranslatableDocument.cs

@@ -62,11 +62,39 @@ public void Translate(IReadOnlyDictionary<string, string> translations)
        }
 
         // rewrite nodes that point to external files (used often for icons, etc.)
-        // these will have relative paths adjusted to absolute path.
-        public virtual void RewriteRelativePathsToAbsolute(string sourceFullPath)
+        // these will have relative paths adjusted to a path relative to the output file.
+        public virtual void RewriteRelativePathsForOutputPath(string sourceFullPath, string outputFullPath)
         {
         }
 
+        /// <summary>
+        /// Computes a relative path from <paramref name="fromDirectory"/> to <paramref name="toPath"/>.
+        /// Falls back to an absolute path if the paths are on different drives.
+        /// </summary>
+        protected static string MakeRelativePath(string fromDirectory, string toPath)
+        {
+            // Ensure fromDirectory ends with a separator so Uri treats it as a directory
+            if (!fromDirectory.EndsWith(Path.DirectorySeparatorChar) &&
+                !fromDirectory.EndsWith(Path.AltDirectorySeparatorChar))
+            {
+                fromDirectory += Path.DirectorySeparatorChar;
+            }
+
+            Uri fromUri = new Uri(fromDirectory);
+            Uri toUri = new Uri(toPath);
+
+            // If on different drives (Windows), fall back to absolute path
+            if (fromUri.Scheme != toUri.Scheme || fromUri.Host != toUri.Host)
+            {
+                return toPath;
+            }
+
+            Uri relativeUri = fromUri.MakeRelativeUri(toUri);
+            string relativePath = Uri.UnescapeDataString(relativeUri.ToString());
+
+            return relativePath.Replace('/', Path.DirectorySeparatorChar);
+        }
+
         protected abstract void LoadCore(TextReader reader);
 
         protected abstract void SaveCore(TextWriter writer);

src/Microsoft.DotNet.XliffTasks/Model/VsctDocument.cs

@@ -74,8 +74,11 @@ private HashSet<string> FindNonUniqueIds()
             return conflictingIds;
         }
 
-        public override void RewriteRelativePathsToAbsolute(string sourceFullPath)
+        public override void RewriteRelativePathsForOutputPath(string sourceFullPath, string outputFullPath)
         {
+            string sourceDir = Path.GetDirectoryName(sourceFullPath);
+            string outputDir = Path.GetDirectoryName(outputFullPath);
+
             foreach (XElement imageTag in Document.Descendants(Document.Root.Name.Namespace + "Bitmap"))
             {
                 XAttribute hrefAttribute = imageTag.Attribute("href");
@@ -84,9 +87,8 @@ public override void RewriteRelativePathsToAbsolute(string sourceFullPath)
                 {
                     string resourceRelativePath = hrefAttribute.Value.Replace('\\', Path.DirectorySeparatorChar);
 
-                    string absolutePath = Path.Combine(Path.GetDirectoryName(sourceFullPath), resourceRelativePath);
-
-                    imageTag.Attribute("href").Value = absolutePath;
+                    string absoluteResourcePath = Path.GetFullPath(Path.Combine(sourceDir, resourceRelativePath));
+                    imageTag.Attribute("href").Value = MakeRelativePath(outputDir, absoluteResourcePath);
                 }
             }
         }

src/Microsoft.DotNet.XliffTasks/Tasks/TranslateSource.cs

@@ -38,7 +38,7 @@ protected override void ExecuteCore()
 
             Directory.CreateDirectory(Path.GetDirectoryName(translatedFullPath));
 
-            sourceDocument.RewriteRelativePathsToAbsolute(Path.GetFullPath(sourcePath));
+            sourceDocument.RewriteRelativePathsForOutputPath(Path.GetFullPath(sourcePath), Path.GetFullPath(translatedFullPath));
             sourceDocument.Save(translatedFullPath);
         }
     }