From 4d7cb9c9fdaac2a1533ce622238640d67e2e4b57 Mon Sep 17 00:00:00 2001
From: Greg Oledzki <greg.oledzki@moderne.io>
Date: Wed, 26 Aug 2026 14:22:46 +0200
Subject: [PATCH] Don't add a newline to a file which doesn't end with a
 newline

---
 .../openrewrite/jgit/api/ApplyCommand.java    |  5 ++-
 .../jgit/api/ApplyCommandTest.java            | 39 +++++++++++++++++++
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/jgit/src/main/java/org/openrewrite/jgit/api/ApplyCommand.java b/jgit/src/main/java/org/openrewrite/jgit/api/ApplyCommand.java
index d9ea89f7e..e6078af66 100644
--- a/jgit/src/main/java/org/openrewrite/jgit/api/ApplyCommand.java
+++ b/jgit/src/main/java/org/openrewrite/jgit/api/ApplyCommand.java
@@ -702,7 +702,10 @@ && canApplyAt(hunkLines, newLines, 0)) {
 			}
 			afterLastHunk = applyAt;
 		}
-		if (!isNoNewlineAtEndOfFile(fh)) {
+		boolean noNewlineAtEnd = afterLastHunk < newLines.size()
+				? rt.isMissingNewlineAtEnd()
+				: isNoNewlineAtEndOfFile(fh);
+		if (!noNewlineAtEnd) {
 			newLines.add(null);
 		}
 		if (!rt.isMissingNewlineAtEnd()) {
diff --git a/jgit/src/test/java/org/openrewrite/jgit/api/ApplyCommandTest.java b/jgit/src/test/java/org/openrewrite/jgit/api/ApplyCommandTest.java
index 237fd9fb9..0e473ddab 100644
--- a/jgit/src/test/java/org/openrewrite/jgit/api/ApplyCommandTest.java
+++ b/jgit/src/test/java/org/openrewrite/jgit/api/ApplyCommandTest.java
@@ -165,6 +165,45 @@ void multiHunkPatchWithMismatchedContextIsRejected()
 				.hasMessageContaining("hunk");
 	}
 
+	/**
+	 * Test that applying a mid-file hunk to a file that has no trailing newline
+	 * preserves the missing trailing newline, matching {@code git apply}.
+	 */
+	@Test
+	void midFileHunkPreservesMissingTrailingNewline() throws Exception {
+		// given
+		StringBuilder fileContent = new StringBuilder();
+		for (int i = 1; i <= 20; i++) {
+			fileContent.append("Line ").append(i);
+			if (i < 20) {
+				fileContent.append('\n');
+			}
+		}
+		writeFileAndCommit("test.txt", fileContent.toString());
+
+		String patch = "diff --git a/test.txt b/test.txt\n"
+				+ "--- a/test.txt\n"
+				+ "+++ b/test.txt\n"
+				+ "@@ -5,6 +5,7 @@\n"
+				+ " Line 5\n"
+				+ " Line 6\n"
+				+ " Line 7\n"
+				+ "+New Line\n"
+				+ " Line 8\n"
+				+ " Line 9\n"
+				+ " Line 10\n";
+
+		// when
+		ApplyResult result = applyPatch(patch);
+
+		// then
+		assertThat(result.getUpdatedFiles()).isNotEmpty();
+		String resultContent = readFile("test.txt");
+		assertThat(resultContent).contains("New Line");
+		assertThat(resultContent).doesNotEndWith("\n");
+		assertThat(resultContent).endsWith("Line 20");
+	}
+
 	private String multiHunkPatch(String eol) {
 		return "diff --git a/test.txt b/test.txt" + eol
 				+ "--- a/test.txt" + eol