Possible incorrect TypeVariable resolution in TypeParameterResolver #1794

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1. harawata commented on Dec 31, 2019

   

   harawata

   on Dec 31, 2019

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   Please explain how to reproduce the problem.
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3. huan0huan commented on Dec 31, 2019

   

   huan0huan

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   I load mapper on my first visit after startup, which may occur when multithreaded access occurs
4. harawata commented on Dec 31, 2019

   

   harawata

   on Dec 31, 2019

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   Please create a small demo project so that we can replicate the issue on our end.
   Here are some project templates to start with. https://github.com/harawata/mybatis-issues
5. huan0huan commented on Dec 31, 2019

   

   huan0huan

   on Dec 31, 2019

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   I've uploaded it。see https://github.com/huan0huan/all-problem
6. harawata

   changed the title [-]Get return value question？[/-] [+]Possible incorrect TypeVariable resolution in TypeParameterResolver[/+] on Dec 31, 2019
7. harawata

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9. harawata

   added this to the 3.5.4 milestone on Dec 31, 2019
10. harawata

    added a commit that references this issue on Dec 31, 2019

    Fix for #1794 Comparing TypeVariable must be done by `equals()`

    7c06b25
11. harawata commented on Dec 31, 2019

    

    harawata

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    Thank you very much for the repro, @huan0huan !

    You are right. The javadoc says:

    Multiple objects may be instantiated at run-time to represent a given type variable. Even though a type variable is created only once, this does not imply any requirement to cache instances representing the type variable. However, all instances representing a type variable must be equal() to each other. As a consequence, users of type variables must not rely on the identity of instances of classes implementing this interface.

    The fix is in the latest 3.5.4-SNAPSHOT.
    Please let me know if you noticed anything!
12. harawata

    closed this as completedon Dec 31, 2019
13. piotrponikowski

    added a commit that references this issue on Jan 4, 2020

    Fix for mybatis#1794 Comparing TypeVariable must be done by `equals()`

    02716da