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  1. Jenkins
  2. JENKINS-5769

RobustReflectionConverter is not used in some cases

    • Icon: Improvement Improvement
    • Resolution: Done
    • Icon: Minor Minor
    • core
    • None

      There are a few cases where XStream internally passes its default instance of ReflectionConverter to other converter instances. When these converters drill down into their fields, they do not use RobustReflectionConverter and the overall conversion becomes subject to the same failures that RobustReflectionConverter was created to avoid. Here is a list of converters that are passed the default ReflectionConverter in XStream 1.3.1:

      ThrowableConverter
      RegexPatternConverter
      SerializableConverter
      LookAndFeelConverter
      SelfStreamingInstanceChecker

      In our case, the fact that the ThrowableConverter was not calling RobustReflectionConvert combined with an error in class member munging described in JENKINS-5768 to cause our build.xml deserializable to fail, cause the build in question to not be loaded into memory on startup.

          [JENKINS-5769] RobustReflectionConverter is not used in some cases

          Alan Harder added a comment -

          I don't think convertAnother can be used, as it will just come back to ThrowableConverter, creating an infinite loop.. know a way around this?

          Alan Harder added a comment - I don't think convertAnother can be used, as it will just come back to ThrowableConverter, creating an infinite loop.. know a way around this?

          mdillon added a comment -

          That must be why they maintain the direct reference to the default converter. You're right that using convertAnother would not be workable. An alternative change for XStream that might be helpful would be for them to add a "protected Converter createReflectionConverter()" on the XStream class. That would let XStream2 replace the default reflection converter with RobustReflectionConverter.

          Putting aside the discussion of what could be changed in XStream itself, does my patch for Hudson seem workable? Aside from the nastiness of having to know the priority associated with the original converters and the lack of the ability to simply replace those converters directly, it seems like a workable approach to me.

          mdillon added a comment - That must be why they maintain the direct reference to the default converter. You're right that using convertAnother would not be workable. An alternative change for XStream that might be helpful would be for them to add a "protected Converter createReflectionConverter()" on the XStream class. That would let XStream2 replace the default reflection converter with RobustReflectionConverter. Putting aside the discussion of what could be changed in XStream itself, does my patch for Hudson seem workable? Aside from the nastiness of having to know the priority associated with the original converters and the lack of the ability to simply replace those converters directly, it seems like a workable approach to me.

          Alan Harder added a comment -

          Yes, both solutions are workable.. we already have a forked XStream, and I'm on the fence about whether to add another custom change in there. But I do like that createReflectionConverter (or maybe createDefaultConverter) idea, as it would make the full registry of converters a bit cleaner.. "replacing" ThrowableConverter, etc. actually leaves the original instances in the registry, though I guess they'd never be used.
          Pattern is a final class, so I'd expect RegexPatternConverter to always work.. SelfStreamingInstanceChecker is for serializing XStream[2] objects which I doubt we'd ever do.. so really only ThrowableConverter matters here, though I guess we can replace them all just for completeness (or modify XStream as you suggested and then they'll all have the right default converter anyway).

          Alan Harder added a comment - Yes, both solutions are workable.. we already have a forked XStream, and I'm on the fence about whether to add another custom change in there. But I do like that createReflectionConverter (or maybe createDefaultConverter) idea, as it would make the full registry of converters a bit cleaner.. "replacing" ThrowableConverter, etc. actually leaves the original instances in the registry, though I guess they'd never be used. Pattern is a final class, so I'd expect RegexPatternConverter to always work.. SelfStreamingInstanceChecker is for serializing XStream [2] objects which I doubt we'd ever do.. so really only ThrowableConverter matters here, though I guess we can replace them all just for completeness (or modify XStream as you suggested and then they'll all have the right default converter anyway).

          Alan Harder added a comment -

          Alan Harder added a comment - Going with createDefaultConverter(). http://github.com/hudson/xstream/commit/b52438619b90231ce6fc37b4d0053079a98567e4

          mdillon added a comment -

          Looks great.

          Also, FWIW, I came to the same conclusion with respect to RegexPatternConverter and SelfStreamingInstanceChecker.

          mdillon added a comment - Looks great. Also, FWIW, I came to the same conclusion with respect to RegexPatternConverter and SelfStreamingInstanceChecker.

          Alan Harder added a comment -

          Waiting on Kohsuke to release XStream 1.3.1-hudson-6 so I can commit the fix.

          Alan Harder added a comment - Waiting on Kohsuke to release XStream 1.3.1-hudson-6 so I can commit the fix.

          mdillon added a comment -

          I noticed in the diff that you changed the pom.xml from 1.3.1-hudson-2 to 1.3.1-hudson-6. Did you happen to check whether the sources in github were otherwise up-to-date with 1.3.1-hudson-5 first?

          mdillon added a comment - I noticed in the diff that you changed the pom.xml from 1.3.1-hudson-2 to 1.3.1-hudson-6. Did you happen to check whether the sources in github were otherwise up-to-date with 1.3.1-hudson-5 first?

          Alan Harder added a comment -

          Yes, I first committed to the "master" branch and noticed the same thing.. looked around and found the "patched" branch which had -hudson-5. Got the commit merged over there before Kohsuke did the release. Thanks for checking

          Alan Harder added a comment - Yes, I first committed to the "master" branch and noticed the same thing.. looked around and found the "patched" branch which had -hudson-5. Got the commit merged over there before Kohsuke did the release. Thanks for checking

          Alan Harder added a comment -
          r28141 | mindless | 2010-03-02 10:55:42 -0800 (Tue, 02 Mar 2010) | 8 lines
          Changed paths:
             M /trunk/hudson/main/core/pom.xml
             M /trunk/hudson/main/core/src/main/java/hudson/util/XStream2.java
             M /trunk/hudson/main/core/src/test/java/hudson/util/XStream2Test.java
             M /trunk/www/changelog.html
          
          [FIXED JENKINS-5769] Update to XStream 1.3.1-hudson-6 where I added 
          protected Converter createDefaultConverter().  This allows a subclass
          to override the default converter (was hardcoded to ReflectionConverter)
          which is also given to the constructor of a few other converters,
          most notably ThrowableConverter.  Override this method in XStream2 to
          provide a RobustReflectionConverter so missing fields in classes
          extending Throwable are handled properly.
          

          Alan Harder added a comment - r28141 | mindless | 2010-03-02 10:55:42 -0800 (Tue, 02 Mar 2010) | 8 lines Changed paths: M /trunk/hudson/main/core/pom.xml M /trunk/hudson/main/core/src/main/java/hudson/util/XStream2.java M /trunk/hudson/main/core/src/test/java/hudson/util/XStream2Test.java M /trunk/www/changelog.html [FIXED JENKINS-5769] Update to XStream 1.3.1-hudson-6 where I added protected Converter createDefaultConverter(). This allows a subclass to override the default converter (was hardcoded to ReflectionConverter) which is also given to the constructor of a few other converters, most notably ThrowableConverter. Override this method in XStream2 to provide a RobustReflectionConverter so missing fields in classes extending Throwable are handled properly.

          Code changed in hudson
          User: : mindless
          Path:
          trunk/hudson/main/core/pom.xml
          trunk/hudson/main/core/src/main/java/hudson/util/XStream2.java
          trunk/hudson/main/core/src/test/java/hudson/util/XStream2Test.java
          trunk/www/changelog.html
          http://jenkins-ci.org/commit/28141
          Log:
          [FIXED JENKINS-5769] Update to XStream 1.3.1-hudson-6 where I added
          protected Converter createDefaultConverter(). This allows a subclass
          to override the default converter (was hardcoded to ReflectionConverter)
          which is also given to the constructor of a few other converters,
          most notably ThrowableConverter. Override this method in XStream2 to
          provide a RobustReflectionConverter so missing fields in classes
          extending Throwable are handled properly.

          SCM/JIRA link daemon added a comment - Code changed in hudson User: : mindless Path: trunk/hudson/main/core/pom.xml trunk/hudson/main/core/src/main/java/hudson/util/XStream2.java trunk/hudson/main/core/src/test/java/hudson/util/XStream2Test.java trunk/www/changelog.html http://jenkins-ci.org/commit/28141 Log: [FIXED JENKINS-5769] Update to XStream 1.3.1-hudson-6 where I added protected Converter createDefaultConverter(). This allows a subclass to override the default converter (was hardcoded to ReflectionConverter) which is also given to the constructor of a few other converters, most notably ThrowableConverter. Override this method in XStream2 to provide a RobustReflectionConverter so missing fields in classes extending Throwable are handled properly.

            mindless Alan Harder
            md5 Mike Dillon
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              Created:
              Updated:
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