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
}
		
		if ((covering instanceof ParenthesizedExpression)
			&& (covering.getParent() instanceof PrefixExpression)
			&& (((PrefixExpression) covering.getParent()).getOperator() == PrefixExpression.Operator.NOT)) {
			negationExpression= (PrefixExpression) covering.getParent();
			parenthesizedExpression= (ParenthesizedExpression) covering;
		}
		
		if (negationExpression == null) {
			return false;
		}
		
		if (resultingCollections == null) {
			return true;
		}
		
		final AST ast= covering.getAST();
		final ASTRewrite rewrite= ASTRewrite.create(ast);
		
		Expression inversedExpression= getInversedBooleanExpression(ast,
			rewrite,
			parenthesizedExpression.getExpression());
		
		boolean keepParentheses= false;
		if (negationExpression.getParent() instanceof Expression) {
			int parentPrecedence= getExpressionPrecedence((Expression) negationExpression.getParent());
			int inversedExpressionPrecedence= getExpressionPrecedence(inversedExpression);
			keepParentheses= parentPrecedence < inversedExpressionPrecedence;
		}