5 files changed, 41 insertions, 15 deletions

diff --git a/src/api/wix/WixToolset.Extensibility/Services/IMessaging.cs b/src/api/wix/WixToolset.Extensibility/Services/IMessaging.cs
index fe77f2a4..15e17e63 100644
--- a/src/api/wix/WixToolset.Extensibility/Services/IMessaging.cs
+++ b/src/api/wix/WixToolset.Extensibility/Services/IMessaging.cs
@@ -16,6 +16,12 @@ namespace WixToolset.Extensibility.Services
         bool EncounteredError { get; }
 
         /// <summary>
+        /// Gets the number of errors encountered thus far.
+        /// </summary>
+        /// <value>The number of errors encountered.</value>
+        int ErrorCount { get; }
+
+        /// <summary>
         /// Gets the last error code encountered during messaging.
         /// </summary>
         /// <value>The exit code for the process.</value>
diff --git a/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs b/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
index e63c727c..a00b4b12 100644
--- a/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
+++ b/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
@@ -157,7 +157,7 @@ namespace WixToolset.Core.CommandLine
             {
                 var document = this.Preprocess(preprocessorVariables, sourceFile, includeSearchPaths, cancellationToken);
 
-                if (this.Messaging.EncounteredError)
+                if (document == null)
                 {
                     continue;
                 }
@@ -358,7 +358,7 @@ namespace WixToolset.Core.CommandLine
             {
                 var document = this.Preprocess(preprocessorVariables, loc, includeSearchPaths, cancellationToken);
 
-                if (this.Messaging.EncounteredError)
+                if (document == null)
                 {
                     continue;
                 }
diff --git a/src/wix/WixToolset.Core/ExtensibilityServices/Messaging.cs b/src/wix/WixToolset.Core/ExtensibilityServices/Messaging.cs
index 280d845c..9a7413f4 100644
--- a/src/wix/WixToolset.Core/ExtensibilityServices/Messaging.cs
+++ b/src/wix/WixToolset.Core/ExtensibilityServices/Messaging.cs
@@ -13,7 +13,9 @@ namespace WixToolset.Core.ExtensibilityServices
         private readonly HashSet<int> suppressedWarnings = new HashSet<int>();
         private readonly HashSet<int> warningsAsErrors = new HashSet<int>();
 
-        public bool EncounteredError { get; private set; }
+        public bool EncounteredError => this.ErrorCount > 0;
+
+        public int ErrorCount { get; private set; }
 
         public int LastErrorNumber { get; private set; }
 
@@ -49,7 +51,7 @@ namespace WixToolset.Core.ExtensibilityServices
 
             if (level == MessageLevel.Error)
             {
-                this.EncounteredError = true;
+                ++this.ErrorCount;
                 this.LastErrorNumber = message.Id;
             }
 
diff --git a/src/wix/WixToolset.Core/Preprocessor.cs b/src/wix/WixToolset.Core/Preprocessor.cs
index 084da8d0..a71e5bb7 100644
--- a/src/wix/WixToolset.Core/Preprocessor.cs
+++ b/src/wix/WixToolset.Core/Preprocessor.cs
@@ -141,6 +141,8 @@ namespace WixToolset.Core
         {
             state.CurrentFileStack.Push(state.Helper.GetVariableValue(state.Context, "sys", "SOURCEFILEDIR"));
 
+            var beforeErrorCount = this.Messaging.ErrorCount;
+
             // Process the reader into the output.
             IPreprocessResult result = null;
             try
@@ -150,7 +152,7 @@ namespace WixToolset.Core
                 // Fire event with post-processed document.
                 this.ProcessedStream?.Invoke(this, new ProcessedStreamEventArgs(state.Context.SourcePath, state.Output));
 
-                if (!this.Messaging.EncounteredError)
+                if (beforeErrorCount == this.Messaging.ErrorCount)
                 {
                     result = this.ServiceProvider.GetService<IPreprocessResult>();
                     result.Document = state.Output;
@@ -292,7 +294,7 @@ namespace WixToolset.Core
                 if (XmlNodeType.ProcessingInstruction == reader.NodeType)
                 {
                     var ignore = false;
-                    string name = null;
+                    string name;
 
                     switch (reader.LocalName)
                     {
@@ -423,7 +425,6 @@ namespace WixToolset.Core
                                 break;
                             }
                         }
-
                     }
                     //else
                     //{
@@ -826,7 +827,7 @@ namespace WixToolset.Core
         private string GetNextToken(ProcessingState state, string originalExpression, ref string expression, out bool stringLiteral)
         {
             stringLiteral = false;
-            var token = String.Empty;
+            string token;
             expression = expression.Trim();
             if (0 == expression.Length)
             {
@@ -1280,7 +1281,7 @@ namespace WixToolset.Core
         /// <returns>Boolean to indicate if the expression is true or false</returns>
         private bool EvaluateExpressionRecurse(ProcessingState state, string originalExpression, ref string expression, PreprocessorOperation prevResultOperation, bool prevResult)
         {
-            var expressionValue = false;
+            bool expressionValue;
             expression = expression.Trim();
             if (expression.Length == 0)
             {
diff --git a/src/wix/test/WixToolsetTest.Converters/Mocks/MockMessaging.cs b/src/wix/test/WixToolsetTest.Converters/Mocks/MockMessaging.cs
index 77821a1c..2bc10772 100644
--- a/src/wix/test/WixToolsetTest.Converters/Mocks/MockMessaging.cs
+++ b/src/wix/test/WixToolsetTest.Converters/Mocks/MockMessaging.cs
@@ -12,7 +12,9 @@ namespace WixToolsetTest.Converters.Mocks
     {
         public List<Message> Messages { get; } = new List<Message>();
 
-        public bool EncounteredError { get; private set; }
+        public bool EncounteredError => this.ErrorCount > 0;
+
+        public int ErrorCount { get; private set; }
 
         public int LastErrorNumber { get; }
 
@@ -22,18 +24,33 @@ namespace WixToolsetTest.Converters.Mocks
 
         public bool WarningsAsError { get; set; }
 
-        public void ElevateWarningMessage(int warningNumber) => throw new NotImplementedException();
+        public void ElevateWarningMessage(int warningNumber)
+        {
+            throw new NotImplementedException();
+        }
 
-        public void SetListener(IMessageListener listener) => throw new NotImplementedException();
+        public void SetListener(IMessageListener listener)
+        {
+            throw new NotImplementedException();
+        }
 
-        public void SuppressWarningMessage(int warningNumber) => throw new NotImplementedException();
+        public void SuppressWarningMessage(int warningNumber)
+        {
+            throw new NotImplementedException();
+        }
 
         public void Write(Message message)
         {
             this.Messages.Add(message);
-            this.EncounteredError |= message.Level == MessageLevel.Error;
+            if (message.Level == MessageLevel.Error)
+            {
+                ++this.ErrorCount;
+            }
         }
 
-        public void Write(string message, bool verbose = false) => throw new NotImplementedException();
+        public void Write(string message, bool verbose = false)
+        {
+            throw new NotImplementedException();
+        }
     }
 }