Merge branch 'sharpen'

reference/antlr4

@@ -1 +1 @@
-Subproject commit a1b85fb2ae7d6475ca83559f47978f2fefd13e4f
+Subproject commit 873001d30c2baa6148783f2ce3be1044c5275d7d

runtime/CSharp/Antlr4.Runtime/Dfa/DFAState.cs

@@ -198,6 +198,8 @@ namespace Antlr4.Runtime.Dfa
         }
 
         public virtual DFAState GetTarget(int symbol)
+        {
+            lock (this)
             {
                 if (edges == null)
                 {
@@ -205,6 +207,7 @@ namespace Antlr4.Runtime.Dfa
                 }
                 return edges[symbol];
             }
+        }
 
         public virtual void SetTarget(int symbol, DFAState target)
         {
@@ -231,6 +234,8 @@ namespace Antlr4.Runtime.Dfa
         }
 
         public virtual DFAState GetContextTarget(int invokingState)
+        {
+            lock (this)
             {
                 if (contextEdges == null)
                 {
@@ -242,6 +247,7 @@ namespace Antlr4.Runtime.Dfa
                 }
                 return contextEdges[invokingState];
             }
+        }
 
         public virtual void SetContextTarget(int invokingState, DFAState target)
         {

runtime/CSharp/Antlr4.Runtime/UnbufferedCharStream.cs

@@ -234,7 +234,7 @@ namespace Antlr4.Runtime
         {
             for (int i = 0; i < n; i++)
             {
-                if (this.n > 0 && data[this.n - 1] == IntStreamConstants.Eof)
+                if (this.n > 0 && data[this.n - 1] == (char)IntStreamConstants.Eof)
                 {
                     return i;
                 }
@@ -278,7 +278,7 @@ namespace Antlr4.Runtime
             {
                 throw new ArgumentOutOfRangeException();
             }
-            if (index > n)
+            if (index >= n)
             {
                 return IntStreamConstants.Eof;
             }
@@ -426,7 +426,7 @@ namespace Antlr4.Runtime
             if (interval.a < bufferStartIndex || interval.b >= bufferStartIndex + n)
             {
                 throw new NotSupportedException("interval " + interval + " outside buffer: " + bufferStartIndex
-                     + ".." + (bufferStartIndex + n));
+                     + ".." + (bufferStartIndex + n - 1));
             }
             // convert from absolute to local index
             int i = interval.a - bufferStartIndex;