WHITESPACE_ONLY/SIMPLE_OPTIMIZATIONS without sourcemaps -> Closure happy, JS broken

[xamde]

WHITESPACE_ONLY/SIMPLE_OPTIMIZATIONS without sourcemaps -> broken js, but Closure is happy

• j2cl build runs fine
• the resulting js does not load in a browser, console says Uncaught SyntaxError: Unexpected token '!' in line 6320.
  The offending line is (added line breaks for readability)

ctor.prototype.$implements__javax_annotation_processing_Generated=true};

Generated.$isInstance=function(instance){
    return instance!=null&&!!instance.$implements__javax_annotation_processing_Generated
};
Generated.$loadModules=function(){};
Generated.$markImplementor(Generated);
$Util.$setClassMetadataForInterface(Generated,"javax.annotation.processing.Generated");
exports=Generated;
return exports});

goog.loadModule(
    function(exports){"use strict";
        goog.module("javax.annotation.processing.Generated");
        goog.require("java.lang.annotation.Annotation");
        goog.require("nativebootstrap.Util");
        var Generated=goog.require("javax.annotation.processing.Generated$impl");
        exports=Generated;
        return exports
});
var global$$module$C_$Users$xamde$_m2$repository$com$vertispan$j2cl$bootstrap$0_10_SNAPSHOT$bootstrap_0_10_SNAPSHOT_jszip_zip!$closure$goog$goog=goog.global;
var require$$module$C_$Users$xamde$_m2$repository$com$vertispan$j2cl$bootstrap$0_10_SNAPSHOT$bootstrap_0_10_SNAPSHOT_jszip_zip!$closure$goog$goog=goog.require;
var define$$module$C_$Users$xamde$_m2$repository$com$vertispan$j2cl$bootstrap$0_10_SNAPSHOT$bootstrap_0_10_SNAPSHOT_jszip_zip!$closure$goog$goog=goog.define;

Running again with SIMPLE_OPTIMIZATIONS leads to the same results. A slightly different js, this time the error is in line 7820.
The browser complains exactly about the ! in NAPSHOT$bootstrap_0_10_SNAPSHOT_jszip_zip!$closure$goog$goog=.
The whole line looks very similar to the one produced from WHITESPACE_ONLY.

Closure logs for both runs end with "success" (marked by maven plugin) and

[INFO]  0 error(s), 0 warning(s)

Full Closure logs for SIMPLE_OPTIMIZATIONS attached in output.log

[niloc132]

Okay, this is almost certainly a non-issue in 0.20 and beyond, since we no longer deal with jszips, but unpack them into a directory to handle them. This was necessary to use some features of closure-compiler, since apparently jszips don't work with features like typedast and others.