Double click in list in "Open with..." dialog does the same as clicking on "OK" button.

src/Main/SharpDevelop/Workbench/DisplayBinding/OpenWithDialog.Designer.cs

@@ -77,6 +77,7 @@ namespace ICSharpCode.SharpDevelop.Workbench
 			this.programListBox.Size = new System.Drawing.Size(268, 156);
 			this.programListBox.TabIndex = 1;
 			this.programListBox.SelectedIndexChanged += new System.EventHandler(this.ProgramListBoxSelectedIndexChanged);
+			this.programListBox.DoubleClick += new System.EventHandler(this.ProgramListBoxDoubleClicked);
 			// 
 			// addButton
 			// 

src/Main/SharpDevelop/Workbench/DisplayBinding/OpenWithDialog.cs

@@ -122,6 +122,11 @@ namespace ICSharpCode.SharpDevelop.Workbench
 			}
 		}
 		
+		void ProgramListBoxDoubleClicked(object sender, EventArgs e)
+		{
+			okButton.PerformClick();
+		}
+		
 		void RemoveButtonClick(object sender, EventArgs e)
 		{
 			SD.DisplayBindingService.RemoveExternalProcessDisplayBinding((ExternalProcessDisplayBinding)SelectedBinding.GetLoadedBinding());