String concatenation in lang::java::m3::AST;

[mschouten1]

Describe the bug
A concatenated string loses everything except for the first two parts.
To Reproduce
Define a string in Java:

String test = "Hello" + "beautiful" + "world";

Create an AST using lang::java::m3::Core and lang::java::m3::AST:

 M3 model = createM3FromMavenProject(projectLocation);
    list[Declaration] asts = [
        createAstFromFile(f, true)
        | f <- files(model.containment), isCompilationUnit(f)
    ];

Print the AST node containing the variable declaration statement.

Expected behavior
All parts of the string are present in the AST node.

Observed behavior
Only the first two parts of the string are present in the AST node.

declarationStatement(variables([],simpleType(id(\"String\")),[variable(id(\"test\"),[],plus(stringLiteral(\"\\\"Hello\\\"\"),stringLiteral(\"\\\"beautiful\\\"\")))]))

[Miljoen]

There are quite some people that rely of this function as part of an ongoing university course, specifically an assignment on code clones.

By disregarding information past the second binary operator, this bug essentially yields invalid clones, preventing many to find the correct number of clones.

Many would be helped a lot if this issue gained priority, but regardless, I just wanted to let the Rascal team know why people are running into this issue.

[jurgenvinju]

@Miljoen thank you! I missed this message because we had not releases java-air yet. Will reproduce it here and see where to fix.