Fix issue in our binary search for a fuzzy name.

src/Workspaces/Core/Portable/FindSymbols/SymbolTree/SymbolTreeInfo.cs

@@ -16,7 +16,7 @@ internal partial class SymbolTreeInfo
 
         /// <summary>
         /// The list of nodes that represent symbols. The primary key into the sorting of this list is the name.
-        /// They are sorted case-insensitively with the <see cref="s_nodeSortComparer" />. Finding case-sensitive
+        /// They are sorted case-insensitively with the <see cref="s_totalComparer" />. Finding case-sensitive
         /// matches can be found by binary searching for something that matches insensitively, and then searching
         /// around that equivalence class for one that matches.
         /// </summary>
@@ -27,6 +27,8 @@ internal partial class SymbolTreeInfo
         /// </summary>
         private readonly BKTree _bkTree;
 
+        private static readonly StringComparer s_caseInsensitiveComparer = CaseInsensitiveComparison.Comparer;
+
         // We first sort in a case insensitive manner.  But, within items that match insensitively, 
         // we then sort in a case sensitive manner.  This helps for searching as we'll walk all 
         // the items of a specific casing at once.  This way features can cache values for that
@@ -35,16 +37,14 @@ internal partial class SymbolTreeInfo
         // they're searching for.  However, with this sort of comparison we now get 
         // "prop, prop, Prop, Prop".  Features can take advantage of that by caching their previous
         // result and reusing it when they see they're getting the same string again.
-        private static readonly Comparison<string> s_nodeSortComparer = (s1, s2) =>
+        private static readonly Comparison<string> s_totalComparer = (s1, s2) =>
         {
-            var diff = CaseInsensitiveComparison.Comparer.Compare(s1, s2);
+            var diff = s_caseInsensitiveComparer.Compare(s1, s2);
             return diff != 0
                 ? diff
                 : StringComparer.Ordinal.Compare(s1, s2);
         };
 
-        private static readonly StringComparer s_nodeEquals = CaseInsensitiveComparison.Comparer;
-
         private SymbolTreeInfo(VersionStamp version, IReadOnlyList<Node> orderedNodes, BKTree bkTree)
         {
             _version = version;
@@ -132,10 +132,9 @@ private IEnumerable<int> FindNodes(string name, StringComparer comparer)
                 }
 
                 int position = startingPosition;
-                while (position > 0 && s_nodeEquals.Equals(_nodes[position - 1].Name, name))
+                while (position > 0 && s_caseInsensitiveComparer.Equals(_nodes[position - 1].Name, name))
                 {
                     position--;
-
                     if (comparer.Equals(_nodes[position].Name, name))
                     {
                         yield return position;
@@ -143,7 +142,7 @@ private IEnumerable<int> FindNodes(string name, StringComparer comparer)
                 }
 
                 position = startingPosition;
-                while (position + 1 < _nodes.Count && s_nodeEquals.Equals(_nodes[position + 1].Name, name))
+                while (position + 1 < _nodes.Count && s_caseInsensitiveComparer.Equals(_nodes[position + 1].Name, name))
                 {
                     position++;
                     if (comparer.Equals(_nodes[position].Name, name))
@@ -155,7 +154,7 @@ private IEnumerable<int> FindNodes(string name, StringComparer comparer)
         }
 
         /// <summary>
-        /// Searches for a name in the ordered list that matches per the <see cref="s_nodeSortComparer" />.
+        /// Searches for a name in the ordered list that matches per the <see cref="s_caseInsensitiveComparer" />.
         /// </summary>
         private int BinarySearch(string name)
         {
@@ -166,7 +165,7 @@ private int BinarySearch(string name)
             {
                 int mid = min + ((max - min) >> 1);
 
-                var comparison =  s_nodeSortComparer(_nodes[mid].Name, name);
+                var comparison =  s_caseInsensitiveComparer.Compare(_nodes[mid].Name, name);
                 if (comparison < 0)
                 {
                     min = mid + 1;
@@ -280,7 +279,7 @@ private static Node[] SortNodes(List<Node> nodes)
 
         private static int CompareNodes(Node x, Node y, IReadOnlyList<Node> nodeList)
         {
-            var comp = s_nodeSortComparer(x.Name, y.Name);
+            var comp = s_totalComparer(x.Name, y.Name);
             if (comp == 0)
             {
                 if (x.ParentIndex != y.ParentIndex)