Studying Late Propagations in Code Clone Evolution Using Software Repository Mining Presented at the 8th International Workshop on Software Clones (IWSC 2014) held in Antwerp, Belgium Paper by Hsiao Hui Mui, Andy Zaidman & Martin Pinzger

1. I, Clone
The paper formerly known as
“Studying Late Propagations in Code Clone
Evolution Using Software Repository Mining”
by Hsiao Hui Mui, Andy Zaidman, Martin Pinzger
Delft University of Technology
IWSC 2014, Antwerp, Belgium

2. What you should know…
Hsiao Hui Mui
Former MSc student
Now working in industry
 Main driver behind this research!

3. I, Robot

4. Plot
A robot goes against his “programming”…
…thereby disobeying the “three laws”1
1. A robot may not injure a human being
2. A robot must obey orders given by a human
3. A robot must protect its own existence
1. By Isaac Asimov

5. • D’oh!!!
• (wrong movie)

6. Plot
A robot goes against his “programming”…
…thereby disobeying the “three laws”1
1. A robot may not injure a programmer
2. A robot must obey orders given by a programmer
3. A robot must protect its own existence
1. By Andy Zaidman

7. I, Late Propagation

8. Law 1:
A clone may not injure a programmer
 Do late propagations cause bugs?
Answer: this paper

9. Law 2:
A clone must obey orders given by a
programmer
 Do late propagations obey?
Answer: code clone management???

10. Law 3:

A clone must protect its own existence
Do late propagations survive, or do they
become inconsistent?
Answer: this paper (partially)

11. Study
System
Revisions
# Clone
Sets
Short-term
Late
Propagations
Long-term
Late
Propagations
#
Bugs
Subclipse
1946
632
1
6
2
JEdit
2481
696
30
5
8
FreeCol
4935
311
8
0
0
Seam
3005
584
0
0
0

12. Q1: Are late propagations frequently occurring?
System
Revisions
# Clone
Sets
Short-term
Late
Propagations
Long-term
Late
Propagations
#
Bugs
Subclipse
1946
632
1
6
2
JEdit
2481
696
30
5
8
FreeCol
4935
311
8
0
0
Seam
3005
584
0
0
0

13. Q2: Do late propagations induce bugs?
System
Revisions
# Clone
Sets
Short-term
Late
Propagations
Long-term
Late
Propagations
#
Bugs
Subclipse
1946
632
1
6
2
JEdit
2481
696
30
5
8
FreeCol
4935
311
8
0
0
Seam
3005
584
0
0
0

14. Q3: Package distance of clone pairs involved in
late propagations?

15. I clone, you clone, we clone…
Questions?