Review

Detector:	MuDetect
Target:	project ' lucene ' version 1918
Misuse:	misuse ' tikanga-1c '
Tags:

Misuse Details

Details about the known misuse from the MUBench dataset.

Description:	In line 48, `SegmentInfos.info()` is called without prior check that there are sufficiently many elements in the `merge.segments` collection. This is the same problem as identified by `tikanga-1`.
Fix Description:
Violation Types:	missing/condition/value_or_state
In File:	org/apache/lucene/index/MergeDocIDRemapper.java
In Method:	MergeDocIDRemapper(SegmentInfos, int[][], int[], OneMerge, int)
Code with Misuse:	`class MergeDocIDRemapper {` `public MergeDocIDRemapper(SegmentInfos infos, int[][] docMaps, int[] delCounts, MergePolicy.OneMerge merge, int mergedDocCount) {` `this.docMaps = docMaps;` `SegmentInfo firstSegment = merge.segments.info(0);` `int i = 0;` `while(true) {` `SegmentInfo info = infos.info(i);` `if (info.equals(firstSegment))` `break;` `minDocID += info.docCount;` `i++;` `}` `int numDocs = 0;` `for(int j=0;j<docMaps.length;i++,j++) {` `numDocs += infos.info(i).docCount;` `assert infos.info(i).equals(merge.segments.info(j));` `}` `maxDocID = minDocID + numDocs;` `starts = new int[docMaps.length];` `newStarts = new int[docMaps.length];` `starts[0] = minDocID;` `newStarts[0] = minDocID;` `for(i=1;i<docMaps.length;i++) {` `final int lastDocCount = merge.segments.info(i-1).docCount;` `starts[i] = starts[i-1] + lastDocCount;` `newStarts[i] = newStarts[i-1] + lastDocCount - delCounts[i-1];` `}` `docShift = numDocs - mergedDocCount;` `// There are rare cases when docShift is 0. It happens` `// if you try to delete a docID that's out of bounds,` `// because the SegmentReader still allocates deletedDocs` `// and pretends it has deletions ... so we can't make` `// this assert here` `// assert docShift > 0;` `// Make sure it all adds up:` `assert docShift == maxDocID - (newStarts[docMaps.length-1] + merge.segments.info(docMaps.length-1).docCount - delCounts[docMaps.length-1]);` `}` `}`

Potential Hits

Findings of the detector that identify an anomaly in the same file and method as the known misuse.

Hit	Rank	Confidence	Confidence String	Pattern Examples	Pattern Support	Pattern Violation	Target Environment Mapping
No	4	0.22417582417582418	(overlap = 12.00 / 13.00)(pattern support = 17 / 70)(violation support = 1 / 1)	lucene/1918/build/src/java/org/apache/lucene/index/DocumentsWriter.java#applyDeletes(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#addIndexesNoOptimize(Directory[]) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#commitMergedDeletes(OneMerge, SegmentReader) lucene/1918/build/src/java/org/apache/lucene/index/LogMergePolicy.java#findMerges(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#applyDeletes()	17
No	8	0.20549450549450549	(overlap = 11.00 / 13.00)(pattern support = 17 / 70)(violation support = 1 / 1)	lucene/1918/build/src/java/org/apache/lucene/index/DocumentsWriter.java#applyDeletes(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#addIndexesNoOptimize(Directory[]) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#commitMergedDeletes(OneMerge, SegmentReader) lucene/1918/build/src/java/org/apache/lucene/index/LogMergePolicy.java#findMerges(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#applyDeletes()	17
No	11	0.16999999999999998	(overlap = 7.00 / 10.00)(pattern support = 17 / 70)(violation support = 1 / 1)	lucene/1918/build/src/java/org/apache/lucene/index/DocumentsWriter.java#applyDeletes(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#addIndexesNoOptimize(Directory[]) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#commitMergedDeletes(OneMerge, SegmentReader) lucene/1918/build/src/java/org/apache/lucene/index/LogMergePolicy.java#findMerges(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#applyDeletes()	17
No	24	0.1349206349206349	(overlap = 5.00 / 9.00)(pattern support = 17 / 70)(violation support = 1 / 1)	lucene/1918/build/src/java/org/apache/lucene/index/DocumentsWriter.java#applyDeletes(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#addIndexesNoOptimize(Directory[]) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#commitMergedDeletes(OneMerge, SegmentReader) lucene/1918/build/src/java/org/apache/lucene/index/LogMergePolicy.java#findMerges(SegmentInfos) lucene/1918/build/src/java/org/apache/lucene/index/IndexWriter.java#applyDeletes()	17

Reviewer Name:	sven
Comment: