Bug 89020 [Undo] Operation throws assertion failure if undo limit is set to 0
I20050324-0800 Unfortunately existing clients of text's undo manager were allowed to set any number without failing. This is no longer possible: an assertion failure occurrs if the limit is smaller than 1. I will add code on my side that will handle the negative numbers but the operation history must allow 0.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
status = operation.execute(monitor, info);
		} catch (OperationCanceledException e) {
			status = Status.CANCEL_STATUS;
		} catch (ExecutionException e) {
			notifyNotOK(operation);
			throw e;
		} catch (Exception e) {
			notifyNotOK(operation);
			throw new ExecutionException(
					"While executing the operation, an exception occurred", e); 
		}
		
		
		if (!merging) {
			if (status.isOK()) {
				notifyDone(operation);
				
				 
				 
				  
				
				if (operation.canUndo()) {
					add(operation);
				}
			} else {
				notifyNotOK(operation);
			}
		} else {
			
			operation.dispose();