[jboss-jira] [JBoss JIRA] (JASSIST-146) ClassFile.compact mangles large class files

[Shigeru Chiba (Commented) (JIRA)]

    [ https://issues.jboss.org/browse/JASSIST-146?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12640097#comment-12640097 ] 

Shigeru Chiba commented on JASSIST-146:
---------------------------------------

The constant pool had been overflowed after executing compact() in the test case
since too many redundant constant pool items were added.
I modified the ConstPool class so that it would not add a duplicated item.
                
> ClassFile.compact mangles large class files
> -------------------------------------------
>
>                 Key: JASSIST-146
>                 URL: https://issues.jboss.org/browse/JASSIST-146
>             Project: Javassist
>          Issue Type: Bug
>    Affects Versions: 3.15.0-GA
>         Environment: Fedora Linux 14 x86_64, Java 1.6.0_27
>            Reporter: Paul Rupe
>            Assignee: Shigeru Chiba
>
> I have a large .class file (1307829 bytes).  Simply reading it in using javassist, calling ClassFile.compact(), then writing it out to a new file creates an invalid class file that is substantially larger (1996560 bytes).
> javap -c throws an EOFException:
> java.io.EOFException
>         at java.io.DataInputStream.readFully(DataInputStream.java:197)
>         at java.io.DataInputStream.readFully(DataInputStream.java:169)
>         at sun.tools.javap.AttrData.read(AttrData.java:54)
>         at sun.tools.javap.FieldData.read(FieldData.java:91)
>         at sun.tools.javap.ClassData.readFields(ClassData.java:211)
>         at sun.tools.javap.ClassData.read(ClassData.java:114)
>         at sun.tools.javap.ClassData.<init>(ClassData.java:70)
>         at sun.tools.javap.JavapPrinter.<init>(JavapPrinter.java:48)
>         at sun.tools.javap.Main.displayResults(Main.java:208)
>         at sun.tools.javap.Main.perform(Main.java:79)
>         at sun.tools.javap.Main.entry(Main.java:67)
>         at sun.tools.javap.Main.main(Main.java:52)
> javassist throws an exception trying to read back the class file it just created:
> java.lang.ClassCastException: javassist.bytecode.FieldrefInfo cannot be cast to javassist.bytecode.Utf8Info
>         at javassist.bytecode.ConstPool.getUtf8Info(ConstPool.java:615)
>         at javassist.bytecode.AttributeInfo.read(AttributeInfo.java:76)
>         at javassist.bytecode.FieldInfo.read(FieldInfo.java:253)
>         at javassist.bytecode.FieldInfo.<init>(FieldInfo.java:63)
>         at javassist.bytecode.ClassFile.read(ClassFile.java:783)
>         at javassist.bytecode.ClassFile.<init>(ClassFile.java:109)
>         at Test.compact(Test.java:21)
>         at Test.main(Test.java:12)
> Attempting to use the new class file in an application results in
> java.lang.ClassFormatError: Invalid this class index 537 in constant pool in class file WorldGenCreateGuild

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