Enable long paths on ResolveComReference task

dotnet · Dec 3, 2018 · e435d47 · e435d47
1 parent a836f05
commit e435d47
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Showing 2 changed files with 23 additions and 12 deletions.
diff --git a/src/Tasks.UnitTests/ComReference_Tests.cs b/src/Tasks.UnitTests/ComReference_Tests.cs
@@ -45,6 +45,8 @@ public void TestStripTypeLibNumber()
                 return; // "COM is only found on Windows"
             }
 
+            Assert.Equal(null, ComReference.StripTypeLibNumberFromPath(null, new FileExists(FileExistsMock)));
+            Assert.Equal("", ComReference.StripTypeLibNumberFromPath("", new FileExists(FileExistsMock)));
             Assert.Equal(@"C:\test\typelib1.dll", ComReference.StripTypeLibNumberFromPath(@"C:\test\typelib1.dll", new FileExists(FileExistsMock)));
             Assert.Equal(@"C:\test\typelib2\2.dll", ComReference.StripTypeLibNumberFromPath(@"C:\test\typelib2\2.dll", new FileExists(FileExistsMock)));
             Assert.Equal(@"C:\test\typelib3.\3dll", ComReference.StripTypeLibNumberFromPath(@"C:\test\typelib3.\3dll", new FileExists(FileExistsMock)));

diff --git a/src/Tasks/ComReference.cs b/src/Tasks/ComReference.cs
@@ -386,18 +386,7 @@ internal static string StripTypeLibNumberFromPath(string typeLibPath, FileExists
                 {
                     try
                     {
-                        var sb = new StringBuilder(NativeMethodsShared.MAX_PATH);
-                        System.Runtime.InteropServices.HandleRef handleRef = new System.Runtime.InteropServices.HandleRef(sb, libraryHandle);
-                        int len = NativeMethodsShared.GetModuleFileName(handleRef, sb, sb.Capacity);
-                        if ((len != 0) &&
-                            ((uint)Marshal.GetLastWin32Error() != NativeMethodsShared.ERROR_INSUFFICIENT_BUFFER))
-                        {
-                            typeLibPath = sb.ToString();
-                        }
-                        else
-                        {
-                            typeLibPath = "";
-                        }
+                        typeLibPath = GetModuleFileName(libraryHandle);
                     }
                     finally
                     {
@@ -413,6 +402,26 @@ internal static string StripTypeLibNumberFromPath(string typeLibPath, FileExists
             return typeLibPath;
         }
 
+        private static string GetModuleFileName(IntPtr handle)
+        {
+            bool success = false;
+            var buffer = new StringBuilder();
+
+            // Try increased buffer sizes if on longpath-enabled Windows
+            for (int bufferSize = NativeMethodsShared.MAX_PATH; !success && bufferSize <= NativeMethodsShared.MaxPath; bufferSize *= 2)
+            {
+                buffer.EnsureCapacity(bufferSize);
+
+                var handleRef = new System.Runtime.InteropServices.HandleRef(buffer, handle);
+                int pathLength = NativeMethodsShared.GetModuleFileName(handleRef, buffer, buffer.Capacity);
+
+                bool isBufferTooSmall = ((uint)Marshal.GetLastWin32Error() == NativeMethodsShared.ERROR_INSUFFICIENT_BUFFER);
+                success = pathLength != 0 && !isBufferTooSmall;
+            }
+
+            return success ? buffer.ToString() : string.Empty;
+        }
+
         /// <summary>
         /// Gets the type lib path for given type lib attributes(reused almost verbatim from vsdesigner utils code)
         /// NOTE:  If there's a typelib number at the end of the path, does NOT strip it.