From 0b4669621a979423127a000550ec462c866b302b Mon Sep 17 00:00:00 2001
From: Jermolene <jeremy@jermolene.com>
Date: Sun, 27 Nov 2016 14:51:51 +0000
Subject: [PATCH] Return all tiddlers when "is" filter operand is missing

---
 core/modules/filters/is.js               | 17 +++++++++++++----
 editions/tw5.com/tiddlers/filters/is.tid |  4 ++--
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/core/modules/filters/is.js b/core/modules/filters/is.js
index 0db243044..514443a62 100644
--- a/core/modules/filters/is.js
+++ b/core/modules/filters/is.js
@@ -28,11 +28,20 @@ Export our filter function
 exports.is = function(source,operator,options) {
 	// Dispatch to the correct isfilteroperator
 	var isFilterOperators = getIsFilterOperators();
-	var isFilterOperator = isFilterOperators[operator.operand];
-	if(isFilterOperator) {
-		return isFilterOperator(source,operator.prefix,options);
+	if(operator.operand) {
+		var isFilterOperator = isFilterOperators[operator.operand];
+		if(isFilterOperator) {
+			return isFilterOperator(source,operator.prefix,options);
+		} else {
+			return [$tw.language.getString("Error/IsFilterOperator")];
+		}
 	} else {
-		return [$tw.language.getString("Error/IsFilterOperator")];
+		// Return all tiddlers if the operand is missing
+		var results = [];
+		source(function(tiddler,title) {
+			results.push(title);
+		});
+		return results;
 	}
 };
 
diff --git a/editions/tw5.com/tiddlers/filters/is.tid b/editions/tw5.com/tiddlers/filters/is.tid
index c274e3a86..113af22c8 100644
--- a/editions/tw5.com/tiddlers/filters/is.tid
+++ b/editions/tw5.com/tiddlers/filters/is.tid
@@ -1,5 +1,5 @@
 created: 20140410103123179
-modified: 20150220161001000
+modified: 20161127142329969
 tags: [[Filter Operators]] [[Common Operators]] [[Negatable Operators]]
 title: is Operator
 type: text/vnd.tiddlywiki
@@ -23,7 +23,7 @@ The parameter <<.place C>> is one of the following fundamental categories:
 |^`tag` |is in use as a tag |
 |^`tiddler` |exists as a non-shadow tiddler |
 
-If <<.place C>> is anything else, the output is an error message.
+If <<.place C>> is anything else an error message is returned. <<.from-version "5.1.14"> if <<.place C>> is blank, the output is passed through unchanged (in earlier versions an error message was returned).
 
 `!is[tiddler]` is a synonym for `is[missing]`, and vice versa.