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Bug 319603

Summary: [1.5][compiler] eclipse fails with 2 generics methods with the same name while javac succeeds
Product: [Eclipse Project] JDT Reporter: Missing name <contact>
Component: CoreAssignee: Srikanth Sankaran <srikanth_sankaran>
Status: VERIFIED FIXED QA Contact:
Severity: normal    
Priority: P3 CC: Olivier_Thomann, satyam.kandula
Version: 3.7Flags: Olivier_Thomann: review+
Target Milestone: 3.6.1   
Hardware: PC   
OS: Windows XP   
Whiteboard:
Attachments:
Description Flags
ant build.xml
none
Class exhibiting the bug
none
Patch under consideration none

Description Missing name CLA 2010-07-12 11:58:23 EDT 
Build Identifier: 20100617-1415

If a class has two methods with generic arguments, one with arguments being subclasses of the other, e.g. :

<T> Collection<T> inter(Collection<T> a, Collection<T> b)
<T> Set<T> inter(Set<T> a, Set<T> b)

then eclipse forgets about the type parameter : in the second method return inter(b, a); yields "Type mismatch: cannot convert from Set<Object> to Set<T>". javac has no problem with this code.


If you rename the first method the problem goes away.

Reproducible: Always

Steps to Reproduce:
1. download both build.xml and CollectionUtils.java
2. put CollectionUtils.java in folder named "src"
3. run ant
4. you should see "CollectionUtils.main() success"
5. try to compile the same class with Eclipse
6. Type mismatch: cannot convert from Set<Object> to Set<T> at line 36
Comment 1 Missing name CLA 2010-07-12 11:59:48 EDT 
Created attachment 174060 [details]
ant build.xml
Comment 2 Missing name CLA 2010-07-12 12:01:02 EDT 
Created attachment 174061 [details]
Class exhibiting the bug
Comment 3 Missing name CLA 2010-07-12 12:05:34 EDT 
I forgot to add that this used to work in eclipse-jee-galileo-SR1. It stopped working in eclipse-jee-galileo-SR2
Comment 4 Srikanth Sankaran CLA 2010-07-13 07:22:27 EDT 
(In reply to comment #3)
> I forgot to add that this used to work in eclipse-jee-galileo-SR1. It stopped
> working in eclipse-jee-galileo-SR2

Regression introduced by the fix for bug 287592.
Under investigation.
Comment 5 Srikanth Sankaran CLA 2010-07-13 11:33:33 EDT 
Created attachment 174167 [details]
Patch under consideration
Comment 6 Srikanth Sankaran CLA 2010-07-13 11:37:41 EDT 
Olivier, please review for 3.6.1
This is a regression introduced in 3.5.2 & 3.6 M3.
Comment 7 Srikanth Sankaran CLA 2010-07-14 01:07:03 EDT 
(In reply to comment #6)
> Olivier, please review for 3.6.1

Easier to review if you start with  ParameterizedGenericMethodBinding.java
and then look at Scope.java. Other changes logically follow from there.
Comment 8 Olivier Thomann CLA 2010-07-21 11:47:47 EDT 
Looks good.
Comment 9 Srikanth Sankaran CLA 2010-07-22 00:29:25 EDT 
Released in HEAD for 3.7 M1
Released in 3.6 maintenance stream for 3.6.1
Comment 10 Satyam Kandula CLA 2010-08-05 01:33:36 EDT 
Verified for 3.7M1 using build I20100802-1800
Comment 11 Srikanth Sankaran CLA 2010-08-05 02:43:03 EDT 
Change status to RESOLVED rather than VERIFIED as this
fix needs to be re-verified for 3.6.1
Comment 12 Frederic Fusier CLA 2010-08-26 09:23:04 EDT 
Verified for 3.6.1 using build M20100825-0800.