diff --git a/moo/mooedit/gtksourceview/upstream/gtksourcecontextengine.c b/moo/mooedit/gtksourceview/upstream/gtksourcecontextengine.c
index ed6c14cc..a9221022 100644
--- a/moo/mooedit/gtksourceview/upstream/gtksourcecontextengine.c
+++ b/moo/mooedit/gtksourceview/upstream/gtksourcecontextengine.c
@@ -134,7 +134,8 @@ typedef enum {
 	GTK_SOURCE_CONTEXT_ENGINE_ERROR_INVALID_WHERE,
 	GTK_SOURCE_CONTEXT_ENGINE_ERROR_INVALID_START_REF,
 	GTK_SOURCE_CONTEXT_ENGINE_ERROR_INVALID_REGEX,
-	GTK_SOURCE_CONTEXT_ENGINE_ERROR_INVALID_STYLE
+	GTK_SOURCE_CONTEXT_ENGINE_ERROR_INVALID_STYLE,
+	GTK_SOURCE_CONTEXT_ENGINE_ERROR_BAD_FILE
 } GtkSourceContextEngineError;
 
 typedef enum {
@@ -2255,13 +2256,9 @@ gtk_source_context_engine_attach_buffer (GtkSourceEngine *engine,
 		main_definition = LOOKUP_DEFINITION (ce->priv->ctx_data, root_id);
 		g_free (root_id);
 
-		if (main_definition == NULL)
-		{
-			g_warning (_("Missing main language "
-				     "definition (id = \"%s\".)"),
-				   ENGINE_ID (ce));
-			return;
-		}
+		/* If we don't abort here, we will crash later (#485661). But it should
+		 * never happen, _gtk_source_context_data_finish_parse checks main context. */
+		g_assert (main_definition != NULL);
 
 		ce->priv->root_context = context_new (NULL, main_definition, NULL, NULL, FALSE);
 		ce->priv->root_segment = create_segment (ce, NULL, ce->priv->root_context, 0, 0, TRUE, NULL);
@@ -6183,8 +6180,11 @@ _gtk_source_context_data_finish_parse (GtkSourceContextData *ctx_data,
 				       GError		   **error)
 {
 	struct ResolveRefData data;
+	gchar *root_id;
+	ContextDefinition *main_definition;
 
 	g_return_val_if_fail (ctx_data != NULL, FALSE);
+	g_return_val_if_fail (ctx_data->lang != NULL, FALSE);
 	g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
 
 	while (overrides != NULL)
@@ -6209,10 +6209,23 @@ _gtk_source_context_data_finish_parse (GtkSourceContextData *ctx_data,
 		g_propagate_error (error, data.error);
 		return FALSE;
 	}
-	else
+
+	/* Engine will crash without main context, check it here (#485661) */
+	root_id = g_strdup_printf ("%s:%s", ctx_data->lang->priv->id, ctx_data->lang->priv->id);
+	main_definition = LOOKUP_DEFINITION (ctx_data, root_id);
+	g_free (root_id);
+
+	if (main_definition == NULL)
 	{
-		return TRUE;
+		g_set_error (error, GTK_SOURCE_CONTEXT_ENGINE_ERROR,
+			     GTK_SOURCE_CONTEXT_ENGINE_ERROR_BAD_FILE,
+			     _("Missing main language "
+			       "definition (id = \"%s\".)"),
+			     ctx_data->lang->priv->id);
+		return FALSE;
 	}
+
+	return TRUE;
 }
 
 static void
diff --git a/moo/mooedit/gtksourceview/upstream/gtksourcestyleschememanager.h b/moo/mooedit/gtksourceview/upstream/gtksourcestyleschememanager.h
index 29b94175..ecac3fe1 100644
--- a/moo/mooedit/gtksourceview/upstream/gtksourcestyleschememanager.h
+++ b/moo/mooedit/gtksourceview/upstream/gtksourcestyleschememanager.h
@@ -58,11 +58,11 @@ struct _GtkSourceStyleSchemeManagerClass
 
 GType			 gtk_source_style_scheme_manager_get_type		(void) G_GNUC_CONST;
 
-GtkSourceStyleSchemeManager
-			*gtk_source_style_scheme_manager_new			(void);
+GtkSourceStyleSchemeManager *
+			 gtk_source_style_scheme_manager_new			(void);
 
-GtkSourceStyleSchemeManager
-			*gtk_source_style_scheme_manager_get_default		(void);
+GtkSourceStyleSchemeManager *
+			 gtk_source_style_scheme_manager_get_default		(void);
 
 void			 gtk_source_style_scheme_manager_set_search_path	(GtkSourceStyleSchemeManager	*manager,
 						    				 gchar			       **path);
diff --git a/moo/mooedit/language-specs/csharp.lang b/moo/mooedit/language-specs/csharp.lang
index 79f770da..7c2fb9d7 100644
--- a/moo/mooedit/language-specs/csharp.lang
+++ b/moo/mooedit/language-specs/csharp.lang
@@ -126,6 +126,7 @@
       <keyword>out</keyword>
       <keyword>override</keyword>
       <keyword>params</keyword>
+      <keyword>partial</keyword>
       <keyword>private</keyword>
       <keyword>protected</keyword>
       <keyword>public</keyword>
diff --git a/moo/mooedit/language-specs/javascript.lang b/moo/mooedit/language-specs/javascript.lang
index 91e3285b..50641a8f 100644
--- a/moo/mooedit/language-specs/javascript.lang
+++ b/moo/mooedit/language-specs/javascript.lang
@@ -25,7 +25,7 @@
 -->
 <language id="js" _name="Javascript" version="2.0" _section="Scripts">
     <metadata>
-        <property name="mimetypes">application/x-javascript;text/x-javascript;text/javascript;text/x-js</property>
+        <property name="mimetypes">application/javascript;application/x-javascript;text/x-javascript;text/javascript;text/x-js</property>
         <property name="globs">*.js</property>
         <property name="line-comment-start">//</property>
         <property name="block-comment-start">/*</property>
diff --git a/moo/mooedit/language-specs/latex.lang b/moo/mooedit/language-specs/latex.lang
index f4904f75..f50ce11a 100644
--- a/moo/mooedit/language-specs/latex.lang
+++ b/moo/mooedit/language-specs/latex.lang
@@ -101,6 +101,22 @@
             <match>\\[a-zA-Z]+</match>
         </context>
 
+        <context id="in-math">
+            <include>
+                <context ref="common-commands"/>
+                <context ref="specials-symbol"/>
+                <context ref="command"/>
+            </include>
+        </context>
+
+        <context id="in-inline-math">
+            <include>
+                <context ref="common-commands"/>
+                <context ref="specials-symbol"/>
+                <context ref="command"/>
+            </include>
+        </context>
+
         <context id="latex">
             <include>
 
@@ -120,27 +136,43 @@
                     </include>
                 </context>
 
-                <context id="math" style-ref="math">
+                <context id="math-1" style-ref="math">
                     <start>\$\$</start>
                     <end>\$\$</end>
                     <include>
                         <context sub-pattern="0" where="start" style-ref="math-bound"/>
                         <context sub-pattern="0" where="end" style-ref="math-bound"/>
-                        <context ref="common-commands"/>
-                        <context ref="specials-symbol"/>
-                        <context ref="command"/>
+                        <context ref="in-math"/>
                     </include>
                 </context>
 
-                <context id="inline-math" style-ref="inline-math">
+                <context id="math-2" style-ref="math">
+                    <start>\\\[</start>
+                    <end>\\\]</end>
+                    <include>
+                        <context sub-pattern="0" where="start" style-ref="math-bound"/>
+                        <context sub-pattern="0" where="end" style-ref="math-bound"/>
+                        <context ref="in-math"/>
+                    </include>
+                </context>
+
+                <context id="inline-math-1" style-ref="inline-math">
                     <start>\$</start>
                     <end>\$</end>
                     <include>
                         <context sub-pattern="0" where="start" style-ref="math-bound"/>
                         <context sub-pattern="0" where="end" style-ref="math-bound"/>
-                        <context ref="common-commands"/>
-                        <context ref="specials-symbol"/>
-                        <context ref="command"/>
+                        <context ref="in-inline-math"/>
+                    </include>
+                </context>
+
+                <context id="inline-math-2" style-ref="inline-math">
+                    <start>\\\(</start>
+                    <end>\\\)</end>
+                    <include>
+                        <context sub-pattern="0" where="start" style-ref="math-bound"/>
+                        <context sub-pattern="0" where="end" style-ref="math-bound"/>
+                        <context ref="in-inline-math"/>
                     </include>
                 </context>
 
diff --git a/moo/mooedit/language-specs/po.lang b/moo/mooedit/language-specs/po.lang
index ec6294b1..aca20b90 100644
--- a/moo/mooedit/language-specs/po.lang
+++ b/moo/mooedit/language-specs/po.lang
@@ -41,6 +41,11 @@
       <include>
         <context ref="def:escape"/>
         <context ref="def:line-continue"/>
+        <context ref="c:printf"/>
+        <context ref="python:format"/>
+        <context id="mnemonic" style-ref="def:special-char">
+          <match>[&amp;_][a-zA-Z]</match>
+        </context>
       </include>
     </context>
     <context id="format" style-ref="comment" end-at-line-end="true">