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
final AST ast= covering.getAST();
		final ASTRewrite rewrite= ASTRewrite.create(ast);
		
		IfStatement firstIfStatement= (IfStatement) coveredNodes.get(0);
		IfStatement firstNewIfStatement= null;
		
		IfStatement prevIfStatement= null;
		for (Iterator I= coveredNodes.iterator(); I.hasNext();) {
			IfStatement ifStatement= (IfStatement) I.next();
			
			IfStatement newIfStatement= ast.newIfStatement();
			newIfStatement.setExpression((Expression) rewrite.createMoveTarget(ifStatement.getExpression()));
			
			Statement thenStatement= (Statement) rewrite.createMoveTarget(ifStatement.getThenStatement());
			if (ifStatement.getThenStatement() instanceof IfStatement) {
				IfStatement ifBodyStatement= (IfStatement) ifStatement.getThenStatement();
				if (ifBodyStatement.getElseStatement() == null) {
					Block thenBlock= ast.newBlock();
					thenBlock.statements().add(thenStatement);
					thenStatement= thenBlock;
				}
			}
			newIfStatement.setThenStatement(thenStatement);
			
			if (prevIfStatement != null) {
				prevIfStatement.setElseStatement(newIfStatement);
				rewrite.remove(ifStatement, null);
			} else {
				firstNewIfStatement= newIfStatement;
			}