Bug 120389 [quick fix] replace conditional with if-else removes + from +=
Using Build I20051102-1600. I create a class [snip] package bla; class Bla { void bla() { boolean cond = true; int i = 42; i += ( cond ) ? 1 : 2; } } [snap] Now I move the cursor over the second cond and trigger the Quickfix 'Replace conditional with if-else'. This results in [snip] int i = 42; if (cond) i = 1; else i = 2; [snap] i.e. replaces the '+=' with '='. (Credit to Jordi Boehme for finding this.)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/correction/AdvancedQuickAssistProcessor.java
InfixExpression expression = (InfixExpression) node;
						InfixExpression.Operator operator = expression.getOperator();
						needParenthesis = (operator == InfixExpression.Operator.LESS)
								|| (operator == InfixExpression.Operator.GREATER)
								|| (operator == InfixExpression.Operator.LESS_EQUALS)
								|| (operator == InfixExpression.Operator.GREATER_EQUALS)
								|| (operator == InfixExpression.Operator.EQUALS)
								|| (operator == InfixExpression.Operator.NOT_EQUALS);
					}
					if (node instanceof InstanceofExpression) {
						needParenthesis = true;
					}
					if (!needParenthesis) {
						return;
					}
					
					ParenthesizedExpression parenthesizedExpression = ast.newParenthesizedExpression();
					Expression expressionPlaceholder = (Expression) rewrite.createCopyTarget(node);
					parenthesizedExpression.setExpression(expressionPlaceholder);
					rewrite.replace(node, parenthesizedExpression, null);
					changedNodes.add(node);
				}
			});
		}
		
		if (changedNodes.isEmpty())
			return false;
		if (resultingCollections == null) {
			return true;
		}