Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 5401)
+++ /CKEditor/trunk/CHANGES.html	(revision 5402)
@@ -155,4 +155,6 @@
 		<li><a href="http://dev.fckeditor.net/ticket/4836">#4836</a> : Using SCAYT result in fragile elements when applying inline styles.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/5425">#5425</a> : [Opera] Disable SCAYT plugin for Opera browser.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/5450">#5450</a> : [FireFox] Press enter on 'replace' button result wrong.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/5121">#5121</a> : recognizes the <br /> tag as a separator when apply block styles in enter_br mode.</li>
 		<li>Updated the following language files:<ul>
 			<li><a href="http://dev.fckeditor.net/ticket/5326">#5326</a> : Catalan;</li>
Index: /CKEditor/trunk/_source/plugins/dialogui/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/dialogui/plugin.js	(revision 5401)
+++ /CKEditor/trunk/_source/plugins/dialogui/plugin.js	(revision 5402)
@@ -508,5 +508,5 @@
 							element.on( 'keydown', function( evt )
 								{
-									if ( evt.data.getKeystroke() in { 32:1, 13:1 } )
+									if ( evt.data.getKeystroke() in { 32:1 } )
 									{
 										me.click();
Index: /CKEditor/trunk/_source/plugins/format/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/format/plugin.js	(revision 5401)
+++ /CKEditor/trunk/_source/plugins/format/plugin.js	(revision 5402)
@@ -22,4 +22,5 @@
 			var tag = tags[ i ];
 			styles[ tag ] = new CKEDITOR.style( config[ 'format_' + tag ] );
+			styles[ tag ]._.enterMode = editor.config.enterMode;
 		}
 
Index: /CKEditor/trunk/_source/plugins/styles/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/styles/plugin.js	(revision 5401)
+++ /CKEditor/trunk/_source/plugins/styles/plugin.js	(revision 5402)
@@ -753,4 +753,8 @@
 		var iterator = range.createIterator();
 		iterator.enforceRealBlocks = true;
+		
+		// make recognize <br /> tag as a separator in ENTER_BR mode (#5121)
+		if ( this._.enterMode ) 
+			iterator.enlargeBr = ( this._.enterMode != CKEDITOR.ENTER_BR );
 
 		var block;
Index: /CKEditor/trunk/_source/plugins/stylescombo/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/stylescombo/plugin.js	(revision 5401)
+++ /CKEditor/trunk/_source/plugins/stylescombo/plugin.js	(revision 5402)
@@ -35,4 +35,5 @@
 							style = styles[ styleName ] = new CKEDITOR.style( styleDefinition );
 							style._name = styleName;
+							style._.enterMode = config.enterMode;
 
 							stylesList.push( style );