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
private static Expression combineOperands(ASTRewrite rewrite, Expression existing, Expression nodeToAdd, boolean removeParenthesis, Operator operator) {
		if (existing == null && removeParenthesis) {
			while (nodeToAdd instanceof ParenthesizedExpression) {
				nodeToAdd= ((ParenthesizedExpression) nodeToAdd).getExpression();
			}
		}
		Expression newRight= (Expression) rewrite.createMoveTarget(nodeToAdd);
		if (existing == null) {
			return newRight;
		}
		AST ast= rewrite.getAST();
		InfixExpression infix= ast.newInfixExpression();
		infix.setOperator(operator);
		infix.setLeftOperand(existing);
		infix.setRightOperand(newRight);
		return infix;
	}
	private static boolean getCastAndAssignIfStatementProposals(IInvocationContext context, ASTNode node, Collection resultingCollections) {
		if (!(node instanceof InstanceofExpression)) {
			return false;
		}
		InstanceofExpression expression= (InstanceofExpression) node;
		
		while (node.getParent() instanceof Expression) {
			node= node.getParent();
		}
		StructuralPropertyDescriptor locationInParent= node.getLocationInParent();
		Statement body= null;
		if (locationInParent == IfStatement.EXPRESSION_PROPERTY) {