Talk given at ICSM 2008 Conference in Beijing, China. Duplicate Bug reports are commonly to pollute bug reporting systems and have negative effects on a development teams' productivity. Therefore, duplicate bug reports are ignored, once identified. The findings in this research work show, that duplicate reports actually contain extra information that is not present in the original bug reports and developers can potentially benefit from this information. We conduct experiments and a case study on ECLIPSE to quantify the amount of extra information. We show that this extra information can be used to enhance techniques related to bug fixing, such as triaging.

1. Duplicate Bug Reports
Considered Harmful ...
Really?!
Nicolas Bettenburg Rahul Premraj Tom Zimmermann Sunghun Kim
Saarland University Saarland University University of Calgary MIT CSAIL
Queenʼs University Vrije Uni. Amsterdam Microsoft Research Hong Kong University

2. 2

3. Duplicate Bug Reports
# 2271
A
Bug Database
3

4. Duplicate Bug Reports
BUG # 2271
A
Bug Database
3

5. Duplicate Bug Reports
# 2271 # 3219
A B
Bug Database
3

6. Duplicate Bug Reports
# 2271 # 3219
A B
Bug Database
4

7. Duplicate Bug Reports
# 2271 # 3219
A B
Bug Database
4

8. What are the
reasons for duplicates?
5

9. Inexperienced Users
6

10. Poor Search Feature
7

11. Multiple Failures - One Defect
8

12. Accidental Resubmission
9

13. FIX THAT BUG!
Intentional Resubmission
10

14. ECLIPSE
20% Duplicates
371 per month
11

15. Duplicate reports are
usually ignored
once identified!
12

16. But Wait!
Is this really
the right
thing to do?
13

17. “Duplicates [...] often
add useful information.
[It is unfortunate that
this information is filed
in a new report.]”
Developer
What Makes a Good Bug Report?
to appear in FSE 2008
14

18. Alan Page
Director of Test Excellence, Microsoft
15

19. Bug duplicates can provide
valuable information [...]
Alan Page
Director of Test Excellence, Microsoft
15

20. Experiment 1
Do duplicate bug reports
contain additional
information?
2 EXPERIMENTS
Experiment 2
Can additional
information improve
bug triaging?
16

21. Experiment 1
Do duplicate bug reports contain additional information?
17

22. The infoZilla Tool
Detects and Extracts
Bug 137808
Summary: Exceptions from createFromString lock-up the editor
Product: [Modeling] EMF Reporter: Patrick Sodre <psodre@gmail.com>
Component: Core Assignee: Marcelo Paternostro <marcelop@ca.ibm.com>
Status: VERIFIED FIXED QA Contact:
Severity: normal
Structural Information:
Priority: P3 CC: merks@ca.ibm.com
Version: 2.2
Target Milestone: ---
Hardware: PC
OS: Windows XP
Whiteboard:
Opened: 2006-04-20 14:25 -
Description:
0400
As discussed on the newsgroup under the Thread with the same name I am opening
this bug entry. Here is a history of the thread.
-- From Ed Merks
Patrick,
The value is checked before it's applied and can't be applied until it's valid.
But this BigDecimal cases behaves oddly because the exception thrown by
new BigDecimal(quot;badvaluequot;)
has a null message and the property editor relies on returning a non-null
SCREENSHOTS
message string to indicate there is an error.
Please open a bugzilla which I'll fix like this:
### Eclipse Workspace Patch 1.0
#P org.eclipse.emf.edit.ui
Index: src/org/eclipse/emf/edit/ui/provider/PropertyDescriptor.java
===================================================================
RCS file:
/cvsroot/tools/org.eclipse.emf/plugins/org.eclipse.emf.edit.ui/src/org/eclipse/emf/edit/ui/provider/PropertyDescriptor.java,v
retrieving revision 1.10
diff -u -r1.10 PropertyDescriptor.java
--- src/org/eclipse/emf/edit/ui/provider/PropertyDescriptor.java 21 Mar 2006
SOURCE CODE
16:42:30 -0000 1.10
+++ src/org/eclipse/emf/edit/ui/provider/PropertyDescriptor.java 20 Apr 2006
11:59:10 -0000
@@ -162,7 +162,8 @@
}
catch (Exception exception)
{
- return exception.getMessage();
+ String message = exception.getMessage();
+ return message == null ? exception.toString() : message;
}
}
Diagnostic diagnostic =
Diagnostician.INSTANCE.validate(EDataTypeCellEditor.this.eDataType, value);
Patrick Sodre wrote:
Hi,
It seems that if the user inputs an invalid parameter that gets created from
quot;createFromStringquot; the Editor locks-up until the user explicitly calls quot;restore
Default Valuequot;.
Is this the expected behavior or could something better be done? For
PATCHES
instance if an exception is thrown restore the value back to what it was before
after displaying a pop-up error message.
I understand that for DataTypes defined by the user he/she should take care
of catching the exceptions but for the default ones like BigInteger/BigDecimal
I think the EMF runtime could do some of the grunt work...
If you think this is something worth pursuing I could post an entry in
Bugzilla.
Regards,
Patrick Sodre
Below is the stack trace that I got from the Editor...
java.lang.NumberFormatException
at java.math.BigDecimal.<init>(BigDecimal.java:368)
at java.math.BigDecimal.<init>(BigDecimal.java:647)
at
org.eclipse.emf.ecore.impl.EcoreFactoryImpl.createEBigDecimalFromString(EcoreFactoryImpl.java:559)
at
org.eclipse.emf.ecore.impl.EcoreFactoryImpl.createFromString(EcoreFactoryImpl.java:116)
at
org.eclipse.emf.edit.ui.provider.PropertyDescriptor$EDataTypeCellEditor.doGetValue(PropertyDescriptor.java:183)
STACK TRACES
at org.eclipse.jface.viewers.CellEditor.getValue(CellEditor.java:449)
at
org.eclipse.ui.views.properties.PropertySheetEntry.applyEditorValue(PropertySheetEntry.java:135)
at
org.eclipse.ui.views.properties.PropertySheetViewer.applyEditorValue(PropertySheetViewer.java:249)
at
------- Comment #1 From Ed Merks 2006-04-20 15:09:23 -0400 -------
The fix has been committed to CVS. Thanks for reporting this problem.
Extracting Structural Information from Bug Reports
MSR 2008

23. Experimental Setup
BUGthisasd
asdlknasdklnasdlk
askdnaklsdn
aksdnlaksdnlkasdkn
asd
sadddda
asdaddasd
aksdnlaskdnlkansd
Master Report Elements
BUGthisasd
asdlknasdklnasdlk
infoZilla
askdnaklsdn
aksdnlkasdkn
asdasdasdasdasd
a
s adddda
a
daddasd
asdasdasdasdasd
askdnlkansd
Duplicate Report Elements
19

24. Experimental Setup
compare
Elements Elements
BUGthisasd
asdlknasdklnasdlk
BUGthisasd
askdnaklsdn asdlknasdklnasdlk
askdnaklsdn
aksdnlaksdnlkasdkn
aksdnlaksdnlkasdkn asd
sadddda
asdaddasd
aksdnlaskdnlkansd
asd BUGthisasd
asdlknasdklnasdlk
askdnaklsdn
sadddda aksdnlkasdkn
asdasdasdasdasd
a
asdaddasd s
adddda
a
aksdnlaskdnlkansd daddasd
asdasdasdasdasd
askdnlkansd
Master Report Extended Report
20

25. ECLIPSE
21

26. 16,511 Master Reports
ECLIPSE
21

27. 16,511 Master Reports
ECLIPSE
27,838 Duplicate Reports
21

28. 16,511 Master Reports
ECLIPSE
27,838 Duplicate Reports
Unique elements per report:
Master Extended 21

29. 16,511 Master Reports
ECLIPSE
27,838 Duplicate Reports
Unique elements per report:
2.5
1.94
2.0 1.83
1.5 1.42
1.0
0.50
0.5 0.29
0.14
0
Patches Stacktraces Screenshots
Master Extended 21

30. Experiment 1
Do duplicate bug reports contain additional information?
22

31. Experiment 1
Do duplicate bug reports contain additional information?
They do!
22

32. Experiment 2
Can additional information improve bug triaging?
23

33. Bug Triage
Developer
24

34. Bug Triage
BUG
Report Developer
24

35. Bug Triage
BUG
Developer
✓BUG
Fixed
Report
24

36. Bug Triage
BUG
BUG
✓
BUG
BUG
BUG BUG
BUG
BUG
Report
BUG Developer Fixed
24

37. Bug Triage
BUG
BUG
✓
BUG
BUG
BUG BUG
BUG
BUG
Report
BUG Triager Developer Fixed
24

38. Experimental Setup
•Machine learning to predict developers
•Train using master reports
•Train using extended reports
•10 Runs
25

39. Results for predicting Top-5 developers
Precision
70.00
65
61 60 60
61.25 58
57 57 56 56
55
52 53 52 52
52.50 51 51
47 47 47 48 48
43.75 42
Run 1 2 3 4 5 6 7 8 9 10 All
Master Extended
26

40. Experiment 2
Can additional information improve bug triaging?
27

41. Experiment 2
Can additional information improve bug triaging?
They can!
27

42. Duplicate reports are
usually ignored
once identified!
28

43. Duplicate reports are
usually ignored
X
once identified!
Merge Reports
28

44. 29

45. 29

46. 29

47. 29

48. 29