Draft compile with compiler.stackMode=strip seems to break stack trace deobfuscation with sourcemaps

[niloc132]

LoggingRPCSuite was apparently written to support running in Chrome with stack mode strip, but still using the "modern" collector (renamed about three years after this commit):

gwt/user/test/com/google/gwt/user/LoggingRPCSuite.gwt.xml

Lines 25 to 40 in 469ef14

	<!-- Turn off emulation to test non-sourcemap mode -->
	<set-property name="compiler.stackMode" value="native"/>
	<!-- when Chrome is enabled, turn off stack trace emulation -->
	<set-property name="compiler.stackMode" value="strip">
	<when-property-is name="user.agent" value="safari"/>
	</set-property>
	<!-- when stack trace stripping is enabled, we need to replace the Null collector
	with one that does something for Chrome -->
	<replace-with class="com.google.gwt.core.client.impl.StackTraceCreator.CollectorChrome">
	<when-type-is class="com.google.gwt.core.client.impl.StackTraceCreator.Collector" />
	<!-- For now, only Chrome provides Error.stack support, so we hijack the
	entire WebKit permutation -->
	<when-property-is name="user.agent" value="safari" />
	<when-property-is name="compiler.useSourceMaps" value="true" />
	</replace-with>

However, this wasn't run since at least ChromeCollector was renamed to ModernCollector (and possibly earlier, haven't confirmed), and running it in recent versions seems to break. When compiled without draft, HtmlUnit is able to send stack traces to the server and have them deobfuscated, so this is likely not a limitation of HtmlUnit vs some other browser.

[niloc132]

Chrome does behave differently than htmlunit here, but still fails the test with draft+stackMode=strip.

Chrome's failure:

expected: <40>, actual: <26>
junit.framework.AssertionFailedError: expected: <40>, actual: <26>
	at java.lang.Throwable.Throwable(com/google/gwt/emul/java/lang/Throwable.java:73)
	at java.lang.Error.Error(com/google/gwt/emul/java/lang/Error.java:30)
	at java.lang.AssertionError.AssertionError(com/google/gwt/emul/java/lang/AssertionError.java:51)
	at com/google/gwt/junit/translatable/junit/framework/AssertionFailedError.java.(com/google/gwt/junit/translatable/junit/framework/AssertionFailedError.java:27)
	at com.google.gwt.jsonp.client.TimeoutException_FieldSerializer.instantiate(TimeoutException_FieldSerializer.java:6)
	at java.lang.Object.$getClass(Object.java:6)
	at com.google.gwt.core.client.impl.Impl.apply(com/google/gwt/user/client/rpc/impl/RequestCallbackAdapter.java:232)
	at com.google.gwt.core.client.impl.AsyncFragmentLoader$HttpDownloadFailure.AsyncFragmentLoader$HttpDownloadFailure(com/google/gwt/http/client/Request.java:227)
	at com/google/gwt/http/client/RequestBuilder.java.(com/google/gwt/http/client/RequestBuilder.java:412)
	at com/google/gwt/xhr/client/XMLHttpRequest.java.(com/google/gwt/xhr/client/XMLHttpRequest.java:329)
	at com.google.gwt.core.client.impl.Impl.apply(com/google/gwt/core/client/impl/Impl.java:299)
	at com.google.gwt.core.client.impl.Impl.entry0(com/google/gwt/core/client/impl/Impl.java:351)
	at com/google/gwt/core/client/impl/Impl.java.(com/google/gwt/core/client/impl/Impl.java:78)

Chrome's actual exception after deobf:

java.lang.RuntimeException: Runtime Exception
	at java.lang.Throwable.Throwable(com/google/gwt/emul/java/lang/Throwable.java:66)
	at java.lang.Exception.Exception(com/google/gwt/emul/java/lang/Exception.java:29)
	at com/google/gwt/emul/java/lang/RuntimeException.java.(com/google/gwt/emul/java/lang/RuntimeException.java:29)
	at com.google.gwt.jsonp.client.TimeoutException_FieldSerializer.$clinit(com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/ModuleUtils.java:39)
	at com.google.gwt.core.client.CodeDownloadException$Reason.valueOf(com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/ModuleUtils.java:35)
	at com.google.gwt.core.client.impl.JavaScriptExceptionBase.$clinit(com/google/gwt/core/client/impl/AsyncFragmentLoader.java:582)
	at com.google.gwt.core.client.impl.AsyncFragmentLoader.onLoad(com/google/gwt/core/client/impl/AsyncFragmentLoader.java:276)
	at com.google.gwt.core.client.impl.Impl.apply(com/google/gwt/core/client/impl/Impl.java:299)
	at com.google.gwt.core.client.impl.Impl.entry0(com/google/gwt/core/client/impl/Impl.java:351)
	at com/google/gwt/core/client/impl/Impl.java.(com/google/gwt/core/client/impl/Impl.java:78)
	at gen/com/google/gwt/user/client/rpc/LoggingRPCTestService_Proxy.java.(gen/com/google/gwt/user/client/rpc/LoggingRPCTestService_Proxy.java:26)
	at Unknown.__installRunAsyncCode(http://localhost:10000/com.google.gwt.user.LoggingRPCSuite.JUnit/com.google.gwt.user.LoggingRPCSuite.JUnit.nocache.js@241:11)
	at Unknown.__gwtInstallCode(com.google.gwt.user.LoggingRPCSuite.JUnit-0.js@584:1)
	at com.google.gwt.core.client.impl.LoadingStrategyBase.gwtInstallCode(com/google/gwt/core/client/impl/LoadingStrategyBase.java:173)
	at com.google.gwt.core.client.JsArrayString.$length(com/google/gwt/core/client/impl/LoadingStrategyBase.java:150)
	at com.google.gwt.core.client.impl.ScriptTagLoadingStrategy.asyncCallback(com/google/gwt/core/client/impl/ScriptTagLoadingStrategy.java:60)
	at com/google/gwt/core/client/impl/ScriptTagLoadingStrategy.java.(com/google/gwt/core/client/impl/ScriptTagLoadingStrategy.java:85)
	at com.google.gwt.core.client.impl.Impl.apply(com/google/gwt/core/client/impl/Impl.java:299)
	at com.google.gwt.core.client.impl.Impl.entry0(com/google/gwt/core/client/impl/Impl.java:351)
	at com/google/gwt/core/client/impl/Impl.java.(com/google/gwt/core/client/impl/Impl.java:78)
	at com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/CollapsedPropertyHolder.java.(com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/CollapsedPropertyHolder.java:32)

Chrome's exception after deobf when not using draft:

java.lang.RuntimeException: Runtime Exception
	at java.lang.Throwable.Throwable(com/google/gwt/emul/java/lang/Throwable.java:66)
	at java.lang.Exception.Exception(com/google/gwt/emul/java/lang/Exception.java:29)
	at com/google/gwt/emul/java/lang/RuntimeException.java.(com/google/gwt/emul/java/lang/RuntimeException.java:29)
	at com.google.gwt.user.client.rpc.LoggingRPCTest.$throwException(com/google/gwt/user/client/rpc/LoggingRPCTest.java:40)
	at java.lang.Throwable.Throwable(com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/ModuleUtils.java:62)
	at com.google.gwt.core.client.impl.AsyncFragmentLoader.$onLoadImpl(com/google/gwt/core/client/impl/AsyncFragmentLoader.java:582)
	at com.google.gwt.core.client.impl.AsyncFragmentLoader.onLoad(com/google/gwt/core/client/impl/AsyncFragmentLoader.java:276)
	at com.google.gwt.core.client.impl.Impl.apply(com/google/gwt/core/client/impl/Impl.java:299)
	at com.google.gwt.core.client.impl.Impl.entry0(com/google/gwt/core/client/impl/Impl.java:351)
	at com/google/gwt/core/client/impl/Impl.java.(com/google/gwt/core/client/impl/Impl.java:78)
	at Unknown.anonymous(com.google.gwt.user.LoggingRPCSuite.JUnit-1.js@7:8)
	at Unknown.__installRunAsyncCode(http://localhost:10000/com.google.gwt.user.LoggingRPCSuite.JUnit/com.google.gwt.user.LoggingRPCSuite.JUnit.nocache.js@241:11)
	at com/google/web/bindery/event/shared/UmbrellaException.java.(com/google/web/bindery/event/shared/UmbrellaException.java:27)
	at com.google.gwt.core.client.impl.LoadingStrategyBase$RequestData.$tryInstall(com/google/gwt/core/client/impl/LoadingStrategyBase.java:173)
	at com.google.gwt.core.client.impl.ScriptTagLoadingStrategy.asyncCallback(com/google/gwt/core/client/impl/ScriptTagLoadingStrategy.java:59)
	at com/google/gwt/core/client/impl/ScriptTagLoadingStrategy.java.(com/google/gwt/core/client/impl/ScriptTagLoadingStrategy.java:85)
	at com.google.gwt.core.client.impl.Impl.apply(com/google/gwt/core/client/impl/Impl.java:299)
	at com.google.gwt.core.client.impl.Impl.entry0(com/google/gwt/core/client/impl/Impl.java:351)
	at com/google/gwt/core/client/impl/Impl.java.(com/google/gwt/core/client/impl/Impl.java:78)
	at Unknown.anonymous(http://localhost:10000/com.google.gwt.user.LoggingRPCSuite.JUnit/deferredjs/474E62227CCEEC7D5C90D27E197E3557/1.cache.js@48:1)

The expected line is

	at com.google.gwt.user.client.rpc.LoggingRPCTest.$throwException(com/google/gwt/user/client/rpc/LoggingRPCTest.java:40)

but going by counting stack frames, we instead get

	at com.google.gwt.jsonp.client.TimeoutException_FieldSerializer.$clinit(com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/ModuleUtils.java:39)

which looks like nonsense (or confusion from merging too many functions due to strip mode).