Merge branch 'stable-5.2' into stable-5.3

* stable-5.2:
  Prepare 5.1.15-SNAPSHOT builds
  JGit v5.1.14.202011251942-r
  GC#deleteOrphans: log warning for deleted orphaned files
  GC#deleteOrphans: handle failure to list files in pack directory
  Ensure that GC#deleteOrphans respects pack lock
  Update API warning filters
  Remove unused imports

Change-Id: Id9386846a202b5ae98dd602744963f8897ddaa8c

4 files changed, 15 insertions, 7 deletions

diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
index 43946265ce..324302c14b 100644
--- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
+++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
@@ -204,6 +204,7 @@ deepenNotWithDeepen=Cannot combine deepen with deepen-not
 deepenSinceWithDeepen=Cannot combine deepen with deepen-since
 deleteBranchUnexpectedResult=Delete branch returned unexpected result {0}
 deleteFileFailed=Could not delete file {0}
+deletedOrphanInPackDir=Deleted orphaned file {}
 deleteRequiresZeroNewId=Delete requires new ID to be zero
 deleteTagUnexpectedResult=Delete tag returned unexpected result {0}
 deletingNotSupported=Deleting {0} not supported.
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
index d51e052b03..59e6d24ca2 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
@@ -265,6 +265,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String deepenSinceWithDeepen;
 	/***/ public String deleteBranchUnexpectedResult;
 	/***/ public String deleteFileFailed;
+	/***/ public String deletedOrphanInPackDir;
 	/***/ public String deleteRequiresZeroNewId;
 	/***/ public String deleteTagUnexpectedResult;
 	/***/ public String deletingNotSupported;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/GC.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/GC.java
index 7400308c86..104d8d4364 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/GC.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/GC.java
@@ -148,6 +148,8 @@ public class GC {
 
 	private static final String INDEX_EXT = "." + PackExt.INDEX.getExtension(); //$NON-NLS-1$
 
+	private static final String KEEP_EXT = "." + PackExt.KEEP.getExtension(); //$NON-NLS-1$
+
 	private static final int DEFAULT_AUTOPACKLIMIT = 50;
 
 	private static final int DEFAULT_AUTOLIMIT = 6700;
@@ -978,11 +980,15 @@ public class GC {
 			fileNames = files.map(path -> path.getFileName().toString())
 					.filter(name -> (name.endsWith(PACK_EXT)
 							|| name.endsWith(BITMAP_EXT)
-							|| name.endsWith(INDEX_EXT)))
+							|| name.endsWith(INDEX_EXT)
+							|| name.endsWith(KEEP_EXT)))
+					// sort files with same base name in the order:
+					// .pack, .keep, .index, .bitmap to avoid look ahead
 					.sorted(Collections.reverseOrder())
 					.collect(Collectors.toList());
-		} catch (IOException e1) {
-			// ignore
+		} catch (IOException e) {
+			LOG.error(e.getMessage(), e);
+			return;
 		}
 		if (fileNames == null) {
 			return;
@@ -990,12 +996,14 @@ public class GC {
 
 		String base = null;
 		for (String n : fileNames) {
-			if (n.endsWith(PACK_EXT)) {
+			if (n.endsWith(PACK_EXT) || n.endsWith(KEEP_EXT)) {
 				base = n.substring(0, n.lastIndexOf('.'));
 			} else {
 				if (base == null || !n.startsWith(base)) {
 					try {
-						Files.delete(packDir.resolve(n));
+						Path delete = packDir.resolve(n);
+						Files.delete(delete);
+						LOG.warn(JGitText.get().deletedOrphanInPackDir, delete);
 					} catch (IOException e) {
 						LOG.error(e.getMessage(), e);
 					}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/GitmoduleEntry.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/GitmoduleEntry.java
index bded527519..4f2e558b26 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/GitmoduleEntry.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/GitmoduleEntry.java
@@ -42,8 +42,6 @@
  */
 package org.eclipse.jgit.lib;
 
-import org.eclipse.jgit.lib.AnyObjectId;
-
 /**
  * A .gitmodules file found in the pack. Store the blob of the file itself (e.g.
  * to access its contents) and the tree where it was found (e.g. to check if it