CodeShovel-error.md

Steps to reproduce the incorrect behaviour of CodeShovel

You first need to run the docker container using the provided image file. See README.md.

The error is occurred while extracting the history of the method equals in src/main/java/org/apache/commons/lang3/StringUtils.java:

    public static boolean equals(CharSequence cs1, CharSequence cs2) { // 781
        return cs1 == null ? cs2 == null : cs1.equals(cs2);            // 782
    }                                                                  // 783

To reproduce the error, first check out the buggy version of Lang-14b to /tmp/Lang-14b.

# in a bash session of the container
defects4j checkout -p Lang -v 14b -w /tmp/Lang-14b
cd /tmp/Lang-14b
git reset --hard c8afaa3e869cc8c25577641553e0d0b5bdac78b5

If you use git log to retrieve the method histories:

git log -L781,783:src/main/java/org/apache/commons/lang3/StringUtils.java

it returns three commits:

• cf2e48a05c250feb636dd337dae1ffb7a1d9d411
• f349629500ff5a85683dff0a807ff8e9b5b88809
• d23b22c78078ee7468e797e80188ae9508c0eee0

Now, let us run CodeShovel to retrieve the histories:

java -Xmx2g -jar /root/workspace/tools/codeshovel-1.0.0-SNAPSHOT.jar -repopath /tmp/Lang-14b -filepath src/main/java/org/apache/commons/lang3/StringUtils.java -methodname equals -startline 781 -outfile output.json

The output then is as follows:

#########################################################################
STARTING ANALYSIS FOR FILE src/main/java/org/apache/commons/lang3/StringUtils.java
-------------------------------------------------------------------------
STARTING ANALYSIS FOR METHOD equals
====================================================
Running Analysis
Commit: HEAD
Method: equals
Lines: 781-783
====================================================

CodeShovel Change History:
fec5e47638aeb2860a604daa0f424a91dbd9a166:Yintroduced(fec5e4:equals:752)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%% RESULT %%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
"fec5e47638aeb2860a604daa0f424a91dbd9a166": "Yintroduced",
FINISHED ANALYSIS FOR METHOD equals
RESULT FILE WRITTEN TO output.json
-------------------------------------------------------------------------
FINISHED ANALYSIS FOR FILE src/main/java/org/apache/commons/lang3/StringUtils.java
#########################################################################
Total duration: 11373

The retrieved commit fec5e47 is actually not related to the target method:

diff --git a/src/main/java/org/apache/commons/lang3/StringUtils.java b/src/main/java/org/apache/commons/lang3/StringUtils.java
index 73aabe4..1ecf255 100644
--- a/src/main/java/org/apache/commons/lang3/StringUtils.java
+++ b/src/main/java/org/apache/commons/lang3/StringUtils.java
@@ -6491,14 +6491,4 @@ public class StringUtils {
         }
     }
 
-    static boolean regionMatchesSequence(CharSequence cs, boolean ignoreCase, int thisStart, 
-                                         CharSequence substring, int start, int length)
-    {
-        if (cs instanceof String) {
-            return ((String) cs).regionMatches(ignoreCase, thisStart, substring, start, length);
-        } else {
-            // TODO: Implement rather than convert to String
-            return cs.toString().regionMatches(ignoreCase, thisStart, substring, start, length);
-    }
-
 }