Merge pull request #228 from andrewparmet/fix/unified-diff-delta-types

wumpz · web-flow · commit 61deff7a0f4c · 2026-05-16T22:30:40.000+02:00
Fix UnifiedDiffReader to use correct DeltaType
diff --git a/java-diff-utils/src/main/java/com/github/difflib/unifieddiff/UnifiedDiffReader.java b/java-diff-utils/src/main/java/com/github/difflib/unifieddiff/UnifiedDiffReader.java
@@ -15,8 +15,12 @@
  */
 package com.github.difflib.unifieddiff;
 
+import com.github.difflib.patch.AbstractDelta;
 import com.github.difflib.patch.ChangeDelta;
 import com.github.difflib.patch.Chunk;
+import com.github.difflib.patch.DeleteDelta;
+import com.github.difflib.patch.EqualDelta;
+import com.github.difflib.patch.InsertDelta;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
@@ -298,23 +302,41 @@ private void processSimilarityIndex(MatchResult match, String line) {
 		private int delLineIdx = 0;
 		private int addLineIdx = 0;
 
-		private void finalizeChunk() {
-				if (!originalTxt.isEmpty() || !revisedTxt.isEmpty()) {
-						actualFile
-										.getPatch()
-										.addDelta(new ChangeDelta<>(
-														new Chunk<>(old_ln - 1, originalTxt, delLineIdxList),
-														new Chunk<>(new_ln - 1, revisedTxt, addLineIdxList)));
-						old_ln = 0;
-						new_ln = 0;
-						originalTxt.clear();
-						revisedTxt.clear();
-						addLineIdxList.clear();
-						delLineIdxList.clear();
-						delLineIdx = 0;
-						addLineIdx = 0;
-				}
-		}
+	private void finalizeChunk() {
+			if (!originalTxt.isEmpty() || !revisedTxt.isEmpty()) {
+					boolean hasDeletes = !delLineIdxList.isEmpty();
+					boolean hasInserts = !addLineIdxList.isEmpty();
+					boolean hasContext = originalTxt.size() != delLineIdxList.size()
+								|| revisedTxt.size() != addLineIdxList.size();
+					AbstractDelta<String> delta;
+					if (hasContext || (hasDeletes && hasInserts)) {
+							delta = new ChangeDelta<>(
+										new Chunk<>(old_ln - 1, originalTxt, delLineIdxList),
+										new Chunk<>(new_ln - 1, revisedTxt, addLineIdxList));
+					} else if (hasDeletes) {
+							delta = new DeleteDelta<>(
+										new Chunk<>(old_ln - 1, originalTxt, delLineIdxList),
+										new Chunk<>(new_ln - 1, revisedTxt, addLineIdxList));
+					} else if (hasInserts) {
+							delta = new InsertDelta<>(
+										new Chunk<>(old_ln - 1, originalTxt, delLineIdxList),
+										new Chunk<>(new_ln - 1, revisedTxt, addLineIdxList));
+					} else {
+							delta = new EqualDelta<>(
+										new Chunk<>(old_ln - 1, originalTxt, delLineIdxList),
+										new Chunk<>(new_ln - 1, revisedTxt, addLineIdxList));
+					}
+					actualFile.getPatch().addDelta(delta);
+					old_ln = 0;
+					new_ln = 0;
+					originalTxt.clear();
+					revisedTxt.clear();
+					addLineIdxList.clear();
+					delLineIdxList.clear();
+					delLineIdx = 0;
+					addLineIdx = 0;
+			}
+	}
 
 		private void processNormalLine(MatchResult match, String line) {
 				String cline = line.substring(1);
diff --git a/java-diff-utils/src/test/java/com/github/difflib/unifieddiff/UnifiedDiffReaderTest.java b/java-diff-utils/src/test/java/com/github/difflib/unifieddiff/UnifiedDiffReaderTest.java
@@ -275,7 +275,7 @@ public void testParseIssue104() throws IOException {
 				assertThat(file.getToFile()).isEqualTo("doc/samba_data_tool_path.xml.in");
 
 				assertThat(file.getPatch().toString())
-								.isEqualTo("Patch{deltas=[[ChangeDelta, position: 0, lines: [] to [@SAMBA_DATA_TOOL@]]]}");
+								.isEqualTo("Patch{deltas=[[InsertDelta, position: 0, lines: [@SAMBA_DATA_TOOL@]]]}");
 
 				assertThat(diff.getTail()).isEqualTo("2.14.4");
 		}

Original file line number	Diff line number	Diff line change
`@@ -275,7 +275,7 @@ public void testParseIssue104() throws IOException {`
`275`	`275`	`assertThat(file.getToFile()).isEqualTo("doc/samba_data_tool_path.xml.in");`
`276`	`276`
`277`	`277`	`assertThat(file.getPatch().toString())`
`278`		`- .isEqualTo("Patch{deltas=[[ChangeDelta, position: 0, lines: [] to [@SAMBA_DATA_TOOL@]]]}");`
	`278`	`+ .isEqualTo("Patch{deltas=[[InsertDelta, position: 0, lines: [@SAMBA_DATA_TOOL@]]]}");`
`279`	`279`
`280`	`280`	`assertThat(diff.getTail()).isEqualTo("2.14.4");`
`281`	`281`	`}`