From d464313d60f4e29c38527334d872879f270a7fbf Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 15 Jan 2026 19:46:34 +0000
Subject: [PATCH] Fix Windows path handling for S3 storage driver

Add pathRel helper method to ImageStore that handles path operations correctly for both local and non-local storage drivers. For S3 and other non-local drivers, use forward slashes consistently to avoid Windows path separator issues where filepath.Rel fails when paths use forward slashes but Windows expects backslashes.

This fixes the memory exhaustion and high CPU usage issue on Windows when using S3 storage, which was caused by infinite loops in GetRepositories and related methods.

Co-authored-by: rchincha <45800463+rchincha@users.noreply.github.com>
---
 pkg/storage/imagestore/imagestore.go | 37 +++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/pkg/storage/imagestore/imagestore.go b/pkg/storage/imagestore/imagestore.go
index da2a6c09..bcf2f903 100644
--- a/pkg/storage/imagestore/imagestore.go
+++ b/pkg/storage/imagestore/imagestore.go
@@ -67,6 +67,35 @@ func (is *ImageStore) DirExists(d string) bool {
 	return is.storeDriver.DirExists(d)
 }
 
+// pathRel computes the relative path from basepath to targpath.
+// For non-local storage drivers (S3, etc.), it uses forward slashes consistently
+// to avoid Windows path separator issues. For local storage, it uses filepath.Rel.
+func (is *ImageStore) pathRel(basepath, targpath string) (string, error) {
+	// For non-local storage drivers (like S3), paths always use forward slashes
+	// regardless of the OS. On Windows, filepath.Rel expects backslashes, which
+	// causes it to fail when working with S3 paths that use forward slashes.
+	// To fix this, we use path package (which always uses /) for non-local drivers.
+	if is.storeDriver.Name() != storageConstants.LocalStorageDriverName {
+		// Ensure both paths use forward slashes
+		basepath = path.Clean(basepath)
+		targpath = path.Clean(targpath)
+
+		// Check if targpath starts with basepath
+		if !strings.HasPrefix(targpath, basepath) {
+			return "", fmt.Errorf("%w: path %s is not under base path %s", zerr.ErrBadConfig, targpath, basepath)
+		}
+
+		// Remove basepath prefix and leading slash
+		rel := strings.TrimPrefix(targpath, basepath)
+		rel = strings.TrimPrefix(rel, "/")
+
+		return rel, nil
+	}
+
+	// For local storage, use filepath.Rel which is platform-aware
+	return filepath.Rel(basepath, targpath)
+}
+
 // NewImageStore returns a new image store backed by cloud storages.
 // see https://github.com/docker/docker.github.io/tree/master/registry/storage-drivers
 // Use the last argument to properly set a cache database, or it will default to boltDB local storage.
@@ -304,7 +333,7 @@ func (is *ImageStore) GetNextRepositories(lastRepo string, maxEntries int, filte
 			return driver.ErrSkipDir
 		}
 
-		rel, err := filepath.Rel(is.rootDir, fileInfo.Path())
+		rel, err := is.pathRel(is.rootDir, fileInfo.Path())
 		if err != nil {
 			return nil //nolint:nilerr // ignore paths that are not under root dir
 		}
@@ -378,7 +407,7 @@ func (is *ImageStore) GetRepositories() ([]string, error) {
 			return driver.ErrSkipDir
 		}
 
-		rel, err := filepath.Rel(is.rootDir, fileInfo.Path())
+		rel, err := is.pathRel(is.rootDir, fileInfo.Path())
 		if err != nil {
 			return nil //nolint:nilerr // ignore paths that are not under root dir
 		}
@@ -429,7 +458,7 @@ func (is *ImageStore) GetNextRepository(processedRepos map[string]struct{}) (str
 			return nil
 		}
 
-		rel, err := filepath.Rel(is.rootDir, fileInfo.Path())
+		rel, err := is.pathRel(is.rootDir, fileInfo.Path())
 		if err != nil {
 			return nil //nolint:nilerr // ignore paths not relative to root dir
 		}
@@ -1305,7 +1334,7 @@ func (is *ImageStore) GetAllDedupeReposCandidates(digest godigest.Digest) ([]str
 	for _, blobPath := range blobsPaths {
 		// these can be both full paths or relative paths depending on the cache options
 		if !is.cache.UsesRelativePaths() && path.IsAbs(blobPath) {
-			blobPath, _ = filepath.Rel(is.rootDir, blobPath)
+			blobPath, _ = is.pathRel(is.rootDir, blobPath)
 		}
 
 		blobsDirIndex := strings.LastIndex(blobPath, "/blobs/")