Infinite loop in SearchEngine.replaceAll if a DocumentFilter blocks replace attempt

[paul-griffith]

e.g in SSCCE FindReplaceDemoApp on
https://github.com/paul-griffith/RSyntaxTextArea/tree/restricted-document-filter

The gist:

1. Create a text area, add a document filter that doesn't allow replacement within a certain subsection.

		textArea.setSyntaxEditingStyle(SyntaxConstants.SYNTAX_STYLE_JAVA);
		textArea.setText("public static void main(String[] args) {\n\t// does nothing\n}");
		RSyntaxDocument document = (RSyntaxDocument) textArea.getDocument();
		document.setDocumentFilter(new DocumentFilter() {
			@Override
			public void replace(FilterBypass fb, int offset, int length, String text, AttributeSet attrs)
				throws BadLocationException {
				if (offset >= 40) {
					super.replace(fb, offset, length, text, attrs);
				}
			}
		});

2. Call SearchEngine.replaceAll for some search text that's in the 'restricted' area, i.e. public, static, void, main in the above snippet.
3. UI thread will block indefinitely due to an infinite loop. From thread dumps, it looks like the replace "context" never moves past the restricted area, so SearchEngine keeps trying to replace the same text infinitely.

"AWT-EventQueue-0@1189" prio=6 tid=0x14 nid=NA runnable
  java.lang.Thread.State: RUNNABLE
	  at java.security.AccessController.getStackAccessControlContext(AccessController.java:-1)
	  at java.security.AccessController.getContext(AccessController.java:833)
	  at java.awt.AWTEvent.<init>(AWTEvent.java:115)
	  at java.awt.event.InvocationEvent.<init>(InvocationEvent.java:286)
	  at java.awt.event.InvocationEvent.<init>(InvocationEvent.java:172)
	  at java.awt.EventQueue.invokeLater(EventQueue.java:1313)
	  at javax.swing.SwingUtilities.invokeLater(SwingUtilities.java:1421)
	  at javax.swing.text.DefaultCaret.changeCaretPosition(DefaultCaret.java:1299)
	  at javax.swing.text.DefaultCaret.handleMoveDot(DefaultCaret.java:1110)
	  at javax.swing.text.DefaultCaret$DefaultFilterBypass.moveDot(DefaultCaret.java:1951)
	  at javax.swing.text.NavigationFilter.moveDot(NavigationFilter.java:79)
	  at org.fife.ui.rtextarea.ConfigurableCaret$FoldAwareNavigationFilter.moveDot(ConfigurableCaret.java:730)
	  at javax.swing.text.DefaultCaret.moveDot(DefaultCaret.java:1101)
	  at javax.swing.text.DefaultCaret.moveDot(DefaultCaret.java:1072)
	  at javax.swing.text.JTextComponent.moveCaretPosition(JTextComponent.java:1563)
	  at javax.swing.text.JTextComponent.select(JTextComponent.java:1934)
	  at javax.swing.text.JTextComponent.setSelectionStart(JTextComponent.java:1852)
	  at org.fife.ui.rsyntaxtextarea.RSyntaxUtilities.selectAndPossiblyCenter(RSyntaxUtilities.java:1337)
	  at org.fife.ui.rtextarea.SearchEngine.find(SearchEngine.java:146)
	  at org.fife.ui.rtextarea.SearchEngine.replace(SearchEngine.java:941)
	  at org.fife.ui.rtextarea.SearchEngine.replaceAll(SearchEngine.java:1026)
	  at org.fife.ui.rsyntaxtextarea.demo.FindAndReplaceDemo.actionPerformed(FindAndReplaceDemo.java:97)
	  at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
	  at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
	  at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
	  at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
	  at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)
	  at java.awt.Component.processMouseEvent(Component.java:6635)
	  at javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
	  at java.awt.Component.processEvent(Component.java:6400)
	  at java.awt.Container.processEvent(Container.java:2263)
	  at java.awt.Component.dispatchEventImpl(Component.java:5011)
	  at java.awt.Container.dispatchEventImpl(Container.java:2321)
	  at java.awt.Component.dispatchEvent(Component.java:4843)
	  at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918)
	  at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4547)
	  at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488)
	  at java.awt.Container.dispatchEventImpl(Container.java:2307)
	  at java.awt.Window.dispatchEventImpl(Window.java:2772)
	  at java.awt.Component.dispatchEvent(Component.java:4843)
	  at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
	  at java.awt.EventQueue$4.run(EventQueue.java:721)
	  at java.awt.EventQueue$4.run(EventQueue.java:715)
	  at java.security.AccessController.doPrivileged(AccessController.java:-1)
	  at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	  at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
	  at java.awt.EventQueue$5.run(EventQueue.java:745)
	  at java.awt.EventQueue$5.run(EventQueue.java:743)
	  at java.security.AccessController.doPrivileged(AccessController.java:-1)
	  at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	  at java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	  at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	  at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	  at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	  at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

[paul-griffith]

I've been working on trying to patch this as a consumer for a little while and had no success. Even within RSyntaxTextArea, it seems like a thorny problem; hoping you might have some ideas. I'll keep working at it and contribute a PR if I come up with anything.

[DevCharly]

Also had recently a endless loop in SearchEngine.replaceAll().
In my case, I had search wrap enabled, which caused the endless loop.

The fix was:

context.setSearchWrap( false );

@bobbylight I think SearchEngine.replaceAll() should ignore the wrap flag

[bobbylight]

Thanks for the bug report, fixed in the latest 3.1.4-SNAPSHOT. Note that SearchResult.getCount() will be wrong in the case of a DocumentFilter silently preventing certain edits to the document. It'll just be the number of matches and (attempted) replacements. I'm not sure how to get around that, but maybe it's not such a big deal - if either of you have any thoughts about that, let me know :)