3 files changed, 22 insertions, 1 deletions
diff --git a/cocoa/ScintillaCocoa.h b/cocoa/ScintillaCocoa.h
index 0c0448118..5aaa386d2 100644
--- a/cocoa/ScintillaCocoa.h
+++ b/cocoa/ScintillaCocoa.h
@@ -198,7 +198,8 @@ public:
   virtual void IdleWork();
   virtual void QueueIdleWork(WorkNeeded::workItems items, int upTo);
   int InsertText(NSString* input);
-  
+  void SelectOnlyMainSelection();
+
   bool KeyboardInput(NSEvent* event);
   void MouseDown(NSEvent* event);
   void MouseMove(NSEvent* event);
diff --git a/cocoa/ScintillaCocoa.mm b/cocoa/ScintillaCocoa.mm
index e348488ff..dfe2e47d1 100644
--- a/cocoa/ScintillaCocoa.mm
+++ b/cocoa/ScintillaCocoa.mm
@@ -1917,6 +1917,21 @@ int ScintillaCocoa::InsertText(NSString* input)
 //--------------------------------------------------------------------------------------------------
 
 /**
+ * Used to ensure that only one selection is active for input composition as composition
+ * does not support multi-typing.
+ * Also drop virtual space as that is not supported by composition.
+ */
+void ScintillaCocoa::SelectOnlyMainSelection()
+{
+  SelectionRange mainSel = sel.RangeMain();
+  mainSel.ClearVirtualSpace();
+  sel.SetSelection(mainSel);
+  Redraw();
+}
+
+//--------------------------------------------------------------------------------------------------
+
+/**
  * Called by the owning view when the mouse pointer enters the control.
  */
 void ScintillaCocoa::MouseEntered(NSEvent* event)
diff --git a/cocoa/ScintillaView.mm b/cocoa/ScintillaView.mm
index f9496cac1..48ccdf1ef 100644
--- a/cocoa/ScintillaView.mm
+++ b/cocoa/ScintillaView.mm
@@ -401,6 +401,11 @@ static NSCursor *cursorFromEnum(Window::Cursor cursor)
                          value: mMarkedTextRange.location + mMarkedTextRange.length];
     currentPosition = mMarkedTextRange.location;
   }
+  else
+  {
+    // Ensure only a single selection
+    mOwner.backend->SelectOnlyMainSelection();
+  }
 
   // Keep Scintilla from collecting undo actions for the composition task.
   undoCollectionWasActive = [mOwner getGeneralProperty: SCI_GETUNDOCOLLECTION] != 0;