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
if (limit > 0) forceUndoLimit(contexts[i], limit - 1);
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#dispose(org.eclipse.core.commands.operations.IUndoContext, boolean, boolean, boolean)
	 */
	public void dispose(IUndoContext context, boolean flushUndo,
			boolean flushRedo, boolean flushContext) {
		
		
		if (flushContext) {
			if (DEBUG_OPERATION_HISTORY_DISPOSE) {
				System.out.print("OPERATIONHISTORY >>> Flushing context ");  
				System.out.print(context);
				System.out.println();
			}
			limits.remove(context);
			flushUndo(context);
			flushRedo(context);
			return;
		}
		if (flushUndo)
			flushUndo(context);
		if (flushRedo)
			flushRedo(context);
	}
	/**
	 * Perform the redo. All validity checks have already occurred.