Options of type Array will now override the default option

Close #876
`triggerStart: []` does not override the default settings.
Options of type `Array` will now override the default option. Before, arrays were merged with the default.

CHANGELOG.md

@@ -4,6 +4,9 @@
     fancytree-drag-remove class not removed on drop/dragend
   * [Fixed] #875 ext-dnd5: Unwanted expanding of folder node when a node is dragged
     before/after it
+  * [Fixed] #876 `triggerStart: []` does not override the default settings.<br>
+    **NOTE:** Options of type `Array` will now override the default option.
+    Before, arrays were merged with the default.
   * [Fixed] ext-ariagrid default actions
 
 # 2.29.0 / 2018-06-16

src/jquery.fancytree.js

@@ -151,6 +151,62 @@ function isVersionAtLeast(dottedVersion, major, minor, patch){
 	return true;
 }
 
+
+/**
+ * Deep-merge a list of objects (but replace array-type options).
+ *
+ * jQuery's $.extend(true, ...) method does a deep merge, that also merges Arrays.
+ * This variant is used to merge extension defaults with user options, and should
+ * merge objects, but override arrays (for example the `triggerStart: [...]` option
+ * of ext-edit). Also `null` values are copied over and not skipped.
+ *
+ * See issue #876
+ *
+ * Example:
+ * _simpleDeepMerge({}, o1, o2);
+ */
+ function _simpleDeepMerge() {
+	var options, name, src, copy, clone,
+		target = arguments[ 0 ] || {},
+		i = 1,
+		length = arguments.length;
+
+	// Handle case when target is a string or something (possible in deep copy)
+	if ( typeof target !== "object" && !$.isFunction( target ) ) {
+		target = {};
+	}
+	if ( i === length ) {
+		throw "need at least two args";
+	}
+	for ( ; i < length; i++ ) {
+		// Only deal with non-null/undefined values
+		if ( ( options = arguments[ i ] ) != null ) {
+			// Extend the base object
+			for ( name in options ) {
+				src = target[ name ];
+				copy = options[ name ];
+				// Prevent never-ending loop
+				if ( target === copy ) {
+					continue;
+				}
+				// Recurse if we're merging plain objects
+				// (NOTE: unlike $.extend, we don't merge arrays, but relace them)
+				if ( copy && jQuery.isPlainObject( copy ) ) {
+					clone = src && jQuery.isPlainObject( src ) ? src : {};
+					// Never move original objects, clone them
+					target[ name ] = _simpleDeepMerge( clone, copy );
+					// Don't bring in undefined values
+				} else if ( copy !== undefined ) {
+					target[ name ] = copy;
+				}
+			}
+		}
+	}
+	// Return the modified object
+	return target;
+}
+
+
 /** Return a wrapper that calls sub.methodName() and exposes
  *  this             : tree
  *  this._local      : tree.ext.EXTNAME
@@ -4911,7 +4967,15 @@ $.widget("ui.fancytree",
 			}
 			// Add extension options as tree.options.EXTENSION
 //			_assert(!this.tree.options[extName], "Extension name must not exist as option name: " + extName);
-			this.tree.options[extName] = $.extend(true, {}, extension.options, this.tree.options[extName]);
+
+			// console.info("extend " + extName, extension.options, this.tree.options[extName])
+			// issue #876: we want to replace custom array-options, not merge them
+			this.tree.options[extName] = _simpleDeepMerge({}, extension.options, this.tree.options[extName]);
+			// this.tree.options[extName] = $.extend(true, {}, extension.options, this.tree.options[extName]);
+
+			// console.info("extend " + extName + " =>", this.tree.options[extName])
+			// console.info("extend " + extName + " org default =>", extension.options)
+
 			// Add a namespace tree.ext.EXTENSION, to hold instance data
 			_assert(this.tree.ext[extName] === undefined, "Extension name must not exist as Fancytree.ext attribute: '" + extName + "'");
 //			this.tree[extName] = extension;