### Eclipse Workspace Patch 1.0
#P org.eclipse.pde.ui
Index: src/org/eclipse/pde/internal/ui/parts/SharedPartWithButtons.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/parts/SharedPartWithButtons.java,v
retrieving revision 1.12
diff -u -r1.12 SharedPartWithButtons.java
--- src/org/eclipse/pde/internal/ui/parts/SharedPartWithButtons.java	8 Jun 2007 16:45:07 -0000	1.12
+++ src/org/eclipse/pde/internal/ui/parts/SharedPartWithButtons.java	24 Oct 2007 07:38:44 -0000
@@ -44,6 +44,19 @@
 			fButtons[index].setEnabled(enabled);
 		}
 	}
+	
+	/**
+	 * Set the specified button's visibility.
+	 * Fix for defect 190717.
+	 * @param index The index of the button to be changed
+	 * @param visible true if the button is to be shown, false if hidden
+	 */
+	public void setButtonVisible(int index, boolean visible) {
+		if (fButtons != null && index >= 0 && fButtons.length > index) {
+			fButtons[index].setVisible(visible);
+		}
+	}
+		
 	protected abstract void createMainControl(Composite parent, int style,
 			int span, FormToolkit toolkit);
 	protected abstract void buttonSelected(Button button, int index);
Index: src/org/eclipse/pde/internal/ui/editor/target/ContentSection.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/editor/target/ContentSection.java,v
retrieving revision 1.19
diff -u -r1.19 ContentSection.java
--- src/org/eclipse/pde/internal/ui/editor/target/ContentSection.java	23 May 2007 18:41:01 -0000	1.19
+++ src/org/eclipse/pde/internal/ui/editor/target/ContentSection.java	24 Oct 2007 07:38:44 -0000
@@ -290,6 +290,16 @@
 		boolean pluginTab = (fLastTab == 0);
 		table.setButtonEnabled(3, isEditable() && pluginTab && !useAllPlugins);
 		table.setButtonEnabled(4, isEditable() && pluginTab && !useAllPlugins && hasItems);
+
+		
+		// Fix for defect 190717
+		// Only show the working set and required buttons on the plugin tab
+		// (retaining the existing enablement logic in the rare case the 
+		// platform doesn't support control.visible=false; I can't imagine
+		// how this would happen, but better to be safe?)
+		table.setButtonVisible(3, pluginTab);
+		table.setButtonVisible(4, pluginTab);
+
 	}
 	
 	protected boolean canPaste(Object target, Object[] objects) {