Bug 286949 [Browser] Bad usage of URL#equals(Object) in WebBrowserEditorInput
HEAD WebBrowserEditorInput#equals(..) calls URL#equals(Object), but the latter resolves the host of the URLs via DNS lookups, which is most of the time not what you want. You should instead compare the strings from URL#toExternalForm(). Furthermore, WebBrowserEditorInput should also override hashCode() (equal objects must have equal hash codes). Note that URL#hashCode() is also broken, so you should use URL#toExternalForm() there as well.
bundles/org.eclipse.ui.browser/src/org/eclipse/ui/internal/browser/WebBrowserEditorInput.java
public WebBrowserEditorInput(URL url, int style, String browserId) {
		super();
		this.url = url;
		this.style = style;
		this.id = browserId;
	}
	/**
	 * WebBrowserEditorInput constructor comment.
	 */
	public WebBrowserEditorInput(URL url, boolean b) {
		this(url);
	}
	public void setName(String n) {
		name = n;
	}
	public void setToolTipText(String t) {
		tooltip = t;
	}
	/**
	 * Returns true if this page can reuse the browser that the given input is
	 * being displayed in, or false if it should open up in a new page.
	 * 
	 * @param input
	 *            org.eclipse.ui.internal.browser.IWebBrowserEditorInput
	 * @return boolean
	 */
	public boolean canReplaceInput(WebBrowserEditorInput input) {
		Trace.trace(Trace.FINEST, "canReplaceInput " + this + " " + input);