Don't change the file name if the text is invalid

src/EditorFeatures/Core.Wpf/InlineRename/Dashboard/DashboardViewModel.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Linq;
@@ -31,6 +30,7 @@ internal class DashboardViewModel : INotifyPropertyChanged, IDisposable
         private bool _defaultRenameInCommentsFlag;
         private bool _defaultRenameFileFlag;
         private bool _defaultPreviewChangesFlag;
+        private bool _isReplacementTextValid;
 
         public DashboardViewModel(InlineRenameSession session)
         {
@@ -52,6 +52,7 @@ public DashboardViewModel(InlineRenameSession session)
 
             // Set the flag to true by default if we're showing the option. Use
             // the property so we correctly update the session as well
+            _isReplacementTextValid = true;
             DefaultRenameFileFlag = session.OptionSet.GetOption(RenameOptions.RenameFile) || AllowFileRename;
         }
 
@@ -70,7 +71,7 @@ private void OnReplacementsComputed(object sender, IInlineRenameReplacementInfo
             var session = (InlineRenameSession)sender;
             _resolvableConflictCount = 0;
             _unresolvableConflictCount = 0;
-
+            _isReplacementTextValid = DefaultRenameFileFlag = result.ReplacementTextValid;
             if (result.ReplacementTextValid)
             {
                 _errorText = null;
@@ -154,7 +155,7 @@ private void UpdateSeverity()
 
         public DashboardSeverity Severity => _severity;
 
-        public bool AllowFileRename => _session.FileRenameInfo == InlineRenameFileRenameInfo.Allowed;
+        public bool AllowFileRename => _session.FileRenameInfo == InlineRenameFileRenameInfo.Allowed && _isReplacementTextValid;
         public bool ShowFileRename => _session.FileRenameInfo != InlineRenameFileRenameInfo.NotAllowed;
         public string FileRenameString => _session.FileRenameInfo switch
         {

src/Workspaces/Core/Portable/Rename/ConflictEngine/ConflictResolver.Session.cs

@@ -25,7 +25,7 @@ namespace Microsoft.CodeAnalysis.Rename.ConflictEngine
     internal static partial class ConflictResolver
     {
         /// <summary>
-        /// Helper class to track the state necessary for finding/resolving conflicts in a 
+        /// Helper class to track the state necessary for finding/resolving conflicts in a
         /// rename session.
         /// </summary>
         private class Session
@@ -84,7 +84,7 @@ private class Session
 
             private struct ConflictLocationInfo
             {
-                // The span of the Node that needs to be complexified 
+                // The span of the Node that needs to be complexified
                 public readonly TextSpan ComplexifiedSpan;
                 public readonly DocumentId DocumentId;
 
@@ -129,7 +129,7 @@ public async Task<MutableConflictResolution> ResolveConflictsAsync()
                             // If the 1st phase results in conflict then we perform then:
                             //      2nd phase is to expand and simplify only the reference locations with conflicts
                             //      3rd phase is to expand and simplify all the conflict locations (both reference and non-reference)
-                            // If there are unresolved Conflicts after the 3rd phase then in 4th phase, 
+                            // If there are unresolved Conflicts after the 3rd phase then in 4th phase,
                             //      We complexify and resolve locations that were resolvable and for the other locations we perform the normal token replacement like the first the phase.
                             // If the OptionSet has RenameFile to true, we rename files with the type declaration
                             for (var phase = 0; phase < 4; phase++)
@@ -209,7 +209,7 @@ public async Task<MutableConflictResolution> ResolveConflictsAsync()
                         }
                     }
 
-                    // This rename could break implicit references of this symbol (e.g. rename MoveNext on a collection like type in a 
+                    // This rename could break implicit references of this symbol (e.g. rename MoveNext on a collection like type in a
                     // foreach/for each statement
                     var renamedSymbolInNewSolution = await GetRenamedSymbolInCurrentSolutionAsync(conflictResolution).ConfigureAwait(false);
 
@@ -238,7 +238,7 @@ public async Task<MutableConflictResolution> ResolveConflictsAsync()
 #endif
 
                     // Step 5: Rename declaration files
-                    if (_optionSet.RenameFile)
+                    if (_optionSet.RenameFile && _replacementTextValid)
                     {
                         var definitionLocations = _renameLocationSet.Symbol.Locations;
                         var definitionDocuments = definitionLocations
@@ -248,7 +248,7 @@ public async Task<MutableConflictResolution> ResolveConflictsAsync()
                         if (definitionDocuments.Count() == 1)
                         {
                             // At the moment, only single document renaming is allowed
-                            conflictResolution.RenameDocumentToMatchNewSymbol(definitionDocuments.Single());
+                            conflictResolution.TryRenameDocumentToMatchNewSymbol(definitionDocuments.Single());
                         }
                     }
 
@@ -265,7 +265,7 @@ private async Task DebugVerifyNoErrorsAsync(MutableConflictResolution conflictRe
             {
                 var documentIdErrorStateLookup = new Dictionary<DocumentId, bool>();
 
-                // we only check for the documentIds we add annotations to, which is a subset of the ones we're going 
+                // we only check for the documentIds we add annotations to, which is a subset of the ones we're going
                 // to change the syntax in.
                 foreach (var documentId in documents)
                 {
@@ -284,7 +284,7 @@ private async Task DebugVerifyNoErrorsAsync(MutableConflictResolution conflictRe
                 {
                     foreach (var documentId in documents)
                     {
-                        // only check documents that had no errors before rename (we might have 
+                        // only check documents that had no errors before rename (we might have
                         // fixed them because of rename).  Also, don't bother checking if a custom
                         // callback was provided.  The caller might be ok with a rename that introduces
                         // errors.
@@ -298,7 +298,7 @@ private async Task DebugVerifyNoErrorsAsync(MutableConflictResolution conflictRe
 #endif
 
             /// <summary>
-            /// Find conflicts in the new solution 
+            /// Find conflicts in the new solution
             /// </summary>
             private async Task<bool> IdentifyConflictsAsync(
                 HashSet<DocumentId> documentIdsForConflictResolution,
@@ -314,7 +314,7 @@ private async Task DebugVerifyNoErrorsAsync(MutableConflictResolution conflictRe
                     var renamedSymbolInNewSolution = await GetRenamedSymbolInCurrentSolutionAsync(conflictResolution).ConfigureAwait(false);
 
                     // if the text replacement is invalid, we just did a simple token replacement.
-                    // Therefore we don't need more mapping information and can skip the rest of 
+                    // Therefore we don't need more mapping information and can skip the rest of
                     // the loop body.
                     if (!IsRenameValid(conflictResolution, renamedSymbolInNewSolution))
                     {
@@ -377,9 +377,9 @@ private async Task DebugVerifyNoErrorsAsync(MutableConflictResolution conflictRe
                                 newReferencedSymbols = GetSymbolsInNewSolution(newDocument, newDocumentSemanticModel, conflictAnnotation, tokenOrNode);
 
                                 // The semantic correctness, after rename, for each token of interest in the
-                                // rename context is performed by getting the symbol pointed by each token 
+                                // rename context is performed by getting the symbol pointed by each token
                                 // and obtain the Symbol's First Ordered Location's  Span-Start and check to
-                                // see if it is the same as before from the base solution. During rename, 
+                                // see if it is the same as before from the base solution. During rename,
                                 // the spans would have been modified and so we need to adjust the old position
                                 // to the new position for which we use the renameSpanTracker, which was tracking
                                 // & mapping the old span -> new span during rename
@@ -496,7 +496,7 @@ private async Task DebugVerifyNoErrorsAsync(MutableConflictResolution conflictRe
             }
 
             /// <summary>
-            /// Gets the list of the nodes that were annotated for a conflict check 
+            /// Gets the list of the nodes that were annotated for a conflict check
             /// </summary>
             private IEnumerable<(SyntaxNodeOrToken syntax, RenameActionAnnotation annotation)> GetNodesOrTokensToCheckForConflicts(
                 SyntaxNode syntaxRoot)

src/Workspaces/Core/Portable/Rename/ConflictEngine/MutableConflictResolution.cs

@@ -89,7 +89,7 @@ internal void UpdateCurrentSolution(Solution solution)
                     var document = CurrentSolution.GetDocument(documentId);
                     var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
 
-                    // For the computeReplacementToken and computeReplacementNode functions, use 
+                    // For the computeReplacementToken and computeReplacementNode functions, use
                     // the "updated" node to maintain any annotation removals from descendants.
                     var newRoot = root.ReplaceSyntax(
                         nodes: annotationSet.GetAnnotatedNodes(root),
@@ -106,8 +106,13 @@ internal void UpdateCurrentSolution(Solution solution)
             return intermediateSolution;
         }
 
-        internal void RenameDocumentToMatchNewSymbol(Document document)
+        internal void TryRenameDocumentToMatchNewSymbol(Document document)
         {
+            if (ReplacementText.IndexOfAny(Path.GetInvalidPathChars()) >= 0)
+            {
+                return;
+            }
+
             var extension = Path.GetExtension(document.Name);
             var newName = Path.ChangeExtension(ReplacementText, extension);