fixes wrongful bail-out

Author: retailcoder

Rubberduck.Core/AutoComplete/Service/SelfClosingPairHandler.cs

@@ -63,7 +63,7 @@ public override CodeString Handle(AutoCompleteEventArgs e, AutoCompleteSettings
                     result = result.ReplaceLine(result.CaretPosition.StartLine, currentLine.TrimEnd());
                 }
 
-                if (e.Character != '\b' && !result.CaretLine.EndsWith($"{pair.OpeningChar}{pair.ClosingChar}"))
+                if (pair.OpeningChar == '(' && e.Character != '\b' && !result.CaretLine.EndsWith($"{pair.OpeningChar}{pair.ClosingChar}"))
                 {
                     // VBE eats it. just bail out.
                     return null;

RubberduckTests/AutoComplete/SelfClosingPairCompletionTests.cs

@@ -34,6 +34,18 @@ public void PlacesCaretBetweenOpeningAndClosingChars()
             Assert.AreEqual(expected, result);
         }
 
+        [Test]
+        public void PlacesCaretBetweenOpeningAndClosingChars_NestedPair()
+        {
+            var pair = new SelfClosingPair('"', '"');
+            var input = pair.OpeningChar;
+            var original = "MsgBox (|)".ToCodeString();
+            var expected = "MsgBox (\"|\")".ToCodeString();
+
+            var result = Run(pair, original, input);
+            Assert.AreEqual(expected, result);
+        }
+
         [Test]
         public void PlacesCaretBetweenOpeningAndClosingChars_PreservesPosition()
         {