fix command line Shift+Insert paste on Linux

Clear the completion preview before pasting, otherwise it gets
converted to regular input.

Additionally, update the completion preview after paste so the
behavior is similar to pasting with Ctrl+v or the mouse.

Author: benoit-pierre

common/content/editor.js

@@ -70,6 +70,10 @@ const Editor = Module("editor", {
                 return;
             }
 
+            // clear completion preview so it does not get turned into regular text
+            if (commandline._completions)
+                commandline._completions.previewClear();
+
             let elem = liberator.focus;
 
             if (elem.setSelectionRange && util.readFromClipboard()) {
@@ -91,6 +95,10 @@ const Editor = Module("editor", {
                 elem.scrollTop = curTop;
                 elem.scrollLeft = curLeft;
             }
+
+            // update completion preview as would happen with Ctrl+v or mouse paste
+            if (commandline._completions && options.autocomplete)
+                commandline._completions.complete(true, false);
     },
 
     // count is optional, defaults to 1