'JsonProtocolParseException: null input' is thrown sometimes during evaluation of object properties

SDK/Debugger version: 0.3.2
Eclipse version: Helios Service Release 2
Google Chrome/V8 Embedder + version: 16.0.912.75
OS + version: Ubuntu 11.10

What steps will reproduce the problem?
1. Open some page in Chrome (e.g. testwebsite/main.html from the chromedevtools 
sources).
2. Start 'WebKit Protocol' debug configuration in Eclipse using WIP Backend 
97678.
3. Stop on a breakpoint
4. Evaluate 'chrome.app' expression (without quotes) in 'Expressions' view.
5. Expand the 'chrome.app' node.

What is the expected result?
Properties of 'chrome.app' object should be shown.

What happens instead?
'Failed to read variables' message is shown.

Please provide any additional information below. If possible, attach a
(reduced) test-case.
The messages from 'Console' view are shown below. It seems that '"set": null' 
property causes 'JsonProtocolParseException: null input' exception.

> Sent to Chrome:
%000{"id":15,"method":"Runtime.getProperties","params":{"ownProperties":true,"ob
jectId":"{\"injectedScriptId\":2,\"id\":70}"}}%00/
> end of message

> Received from Chrome:
%000{"result":{"result":[{"value":{"type":"function","objectId":"{\"injectedScri
ptId\":2,\"id\":71}","className":"Object","description":"function Install() { 
[native code] 
}"},"writable":true,"enumerable":true,"configurable":true,"name":"install"},{"va
lue":{"type":"object","objectId":"{\"injectedScriptId\":2,\"id\":72}","className
":"Object","description":"Object"},"writable":true,"enumerable":true,"configurab
le":true,"name":"experimental"},{"value":{"type":"function","objectId":"{\"injec
tedScriptId\":2,\"id\":73}","className":"Object","description":"function 
GetDetailsForFrame() { [native code] 
}"},"writable":true,"enumerable":true,"configurable":true,"name":"getDetailsForF
rame"},{"value":{"type":"function","objectId":"{\"injectedScriptId\":2,\"id\":74
}","className":"Object","description":"function GetDetails() { [native code] 
}"},"writable":true,"enumerable":true,"configurable":true,"name":"getDetails"},{
"get":{"type":"function","objectId":"{\"injectedScriptId\":2,\"id\":75}","classN
ame":"Object","description":"function GetIsInstalled() { [native code] 
}"},"set":null,"enumerable":true,"configurable":true,"name":"isInstalled"},{"nam
e":"__proto__","value":{"type":"object","objectId":"{\"injectedScriptId\":2,\"id
\":76}","className":"Object","description":"Object"},"writable":true,"configurab
le":true,"enumerable":false}]},"id":15}%00/
> end of message

Original issue reported on code.google.com by nikolay....@gmail.com on 23 Jan 2012 at 9:20

The stacktrace from 'Error Log' view:

java.lang.RuntimeException: Exception occured in callback
at org.chromium.sdk.CallbackSemaphore.tryAcquire(CallbackSemaphore.java:68)
at 
org.chromium.sdk.CallbackSemaphore.tryAcquireDefault(CallbackSemaphore.java:33)
at org.chromium.sdk.CallbackSemaphore.acquireDefault(CallbackSemaphore.java:40)
at 
org.chromium.sdk.internal.wip.WipValueLoader.loadRawPropertiesSync(WipValueLoade
r.java:313)
at 
org.chromium.sdk.internal.wip.WipValueLoader.access$3(WipValueLoader.java:278)
at 
org.chromium.sdk.internal.wip.WipValueLoader$2.runSync(WipValueLoader.java:238)
at org.chromium.sdk.util.AsyncFuture$SyncOperation.execute(AsyncFuture.java:167)
at 
org.chromium.sdk.internal.wip.WipValueLoader.loadPropertiesInFuture(WipValueLoad
er.java:262)
at 
org.chromium.sdk.internal.wip.WipValueLoader.loadJsObjectPropertiesInFuture(WipV
alueLoader.java:70)
at 
org.chromium.sdk.internal.wip.WipValueBuilder$ObjectTypeBase$JsObjectBase.doLoad
Properties(WipValueBuilder.java:258)
at 
org.chromium.sdk.internal.wip.WipValueBuilder$ObjectTypeBase$JsObjectBase.getLoa
dedProperties(WipValueBuilder.java:240)
at 
org.chromium.sdk.internal.wip.WipValueBuilder$ObjectTypeBase$JsObjectBase.getPro
perties(WipValueBuilder.java:203)
at org.chromium.debug.core.model.Value.getVariables(Value.java:73)
at 
org.eclipse.debug.internal.ui.model.elements.VariableContentProvider.getValueChi
ldren(VariableContentProvider.java:166)
at 
org.eclipse.debug.internal.ui.model.elements.VariableContentProvider.getAllChild
ren(VariableContentProvider.java:83)
at 
org.eclipse.debug.internal.ui.model.elements.VariableContentProvider.getChildCou
nt(VariableContentProvider.java:48)
at 
org.eclipse.debug.internal.ui.model.elements.ElementContentProvider.retrieveChil
dCount(ElementContentProvider.java:114)
at 
org.eclipse.debug.internal.ui.model.elements.ElementContentProvider$2.run(Elemen
tContentProvider.java:63)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)
Caused by: java.lang.Exception: Exception saved from callback
at org.chromium.sdk.CallbackSemaphore.callbackDone(CallbackSemaphore.java:80)
at 
org.chromium.sdk.internal.BaseCommandProcessor.callThemBack(BaseCommandProcessor
.java:141)
at 
org.chromium.sdk.internal.BaseCommandProcessor.processIncoming(BaseCommandProces
sor.java:104)
at 
org.chromium.sdk.internal.wip.WipCommandProcessor.acceptResponse(WipCommandProce
ssor.java:105)
at 
org.chromium.sdk.internal.wip.WipTabImpl$2.textMessageRecieved(WipTabImpl.java:9
7)
at 
org.chromium.sdk.internal.websocket.WsConnection$7$1.dispatch(WsConnection.java:
210)
at 
org.chromium.sdk.internal.websocket.WsConnection$8.runImpl(WsConnection.java:271
)
at org.chromium.sdk.internal.websocket.WsConnection$8.run(WsConnection.java:262)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.RuntimeException: 
org.chromium.sdk.internal.protocolparser.JsonProtocolParseException: Failed to 
parse field result
at 
org.chromium.sdk.internal.wip.WipCommandProcessor$6.onSuccess(WipCommandProcesso
r.java:89)
at 
org.chromium.sdk.internal.wip.WipCommandCallback$Default.messageReceived(WipComm
andCallback.java:30)
at 
org.chromium.sdk.internal.wip.WipCommandCallback$Default.messageReceived(WipComm
andCallback.java:1)
at 
org.chromium.sdk.internal.BaseCommandProcessor$3.call(BaseCommandProcessor.java:
100)
at 
org.chromium.sdk.internal.BaseCommandProcessor$3.call(BaseCommandProcessor.java:
1)
at 
org.chromium.sdk.internal.BaseCommandProcessor.callThemBack(BaseCommandProcessor
.java:134)
... 7 more
Caused by: org.chromium.sdk.internal.protocolparser.JsonProtocolParseException: 
Failed to parse field result
at 
org.chromium.sdk.internal.wip.protocol.GeneratedWipProtocolParser$Value_94.<init
>(GeneratedWipProtocolParser.java:7115)
at 
org.chromium.sdk.internal.wip.protocol.GeneratedWipProtocolParser$Value_94.parse
(GeneratedWipProtocolParser.java:7083)
at 
org.chromium.sdk.internal.wip.protocol.GeneratedWipProtocolParser.parseRuntimeGe
tPropertiesData(GeneratedWipProtocolParser.java:124)
at 
org.chromium.sdk.internal.wip.protocol.output.runtime.GetPropertiesParams.parseR
esponse(GetPropertiesParams.java:29)
at 
org.chromium.sdk.internal.wip.protocol.output.runtime.GetPropertiesParams.parseR
esponse(GetPropertiesParams.java:1)
at 
org.chromium.sdk.internal.wip.WipCommandProcessor$6.onSuccess(WipCommandProcesso
r.java:87)
... 12 more
Caused by: org.chromium.sdk.internal.protocolparser.JsonProtocolParseException: 
Failed to parse field set
at 
org.chromium.sdk.internal.wip.protocol.GeneratedWipProtocolParser$Value_95.<init
>(GeneratedWipProtocolParser.java:7198)
at 
org.chromium.sdk.internal.wip.protocol.GeneratedWipProtocolParser$Value_95.parse
(GeneratedWipProtocolParser.java:7130)
at 
org.chromium.sdk.internal.wip.protocol.GeneratedWipProtocolParser$Value_94.<init
>(GeneratedWipProtocolParser.java:7108)
... 17 more
Caused by: org.chromium.sdk.internal.protocolparser.JsonProtocolParseException: 
null input
at 
org.chromium.sdk.internal.wip.protocol.GeneratedWipProtocolParser$Value_95.<init
>(GeneratedWipProtocolParser.java:7192)
... 19 more

Original comment by nikolay....@gmail.com on 23 Jan 2012 at 10:59

yinxianwei / chromedevtools

'JsonProtocolParseException: null input' is thrown sometimes during evaluation of object properties #58