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
List statements = coveringMetod.getBody().statements();
		int ifIndex = statements.indexOf(ifStatement);
		if (ifIndex == -1) {
			return false;
		}
		
		if (resultingCollections == null) {
			return true;
		}
		
		AST ast = coveringStatement.getAST();
		ASTRewrite rewrite = ASTRewrite.create(ast);
		
		ListRewrite listRewriter = rewrite.getListRewrite(thenBlock,
			(ChildListPropertyDescriptor) ifStatement.getLocationInParent());
		listRewriter.remove((ASTNode) thenStatements.get(thenStatements.size() - 1), null);
		
		Expression conditionPlaceholder = (Expression) rewrite.createMoveTarget(ifStatement.getExpression());
		Statement thenPlaceholder = (Statement) rewrite.createMoveTarget(ifStatement.getThenStatement());
		
		Block elseBlock = ast.newBlock();
		for (int i = ifIndex + 1; i < statements.size(); i++) {
			Statement statement = (Statement) statements.get(i);
			elseBlock.statements().add(rewrite.createMoveTarget(statement));
		}
		
		IfStatement newIf = ast.newIfStatement();
		newIf.setExpression(conditionPlaceholder);
		newIf.setThenStatement(thenPlaceholder);